Title of Invention

COMPUTERIZED AUTOMATED DYNAMIC CONTROL SYSTEM FOR SINGLE -TRACK VEHICLES

Abstract Various methods, apparatuses, and systems in which a single-track vehicle has a retractable auxiliary-support wheel assembly and a computer control system. In an embodiment, the single-track vehicle has an elongated body. The retractable auxiliary support wheel assembly mounts on both sides of the elongated body. The computer control system analyzes signals from one or more sensors to dynamically balance the single-track vehicle. (FIG. - 1)
Full Text TECHNICAL FIELD
In general, embodiment of the invention may relate to a single track vehicle
controlled through use of a control algorithms. In particular an aspect of an embodiment
of the invention relates to automated steering control for achieving dynamic balancing of
single-track vehicles.
BACKGROUND OF THE INVENTION
Generally, Single-track vehicles (motorcycles, scooters, mopeds and bicycles).
enjoy significant advantage over dual-track vehicles (such as cars) in terms of handling
(i.e. maneuverability, acceleration, slalom) and energy efficiency. It is obvious when we
compare a typical single-track vehicle with a typical car: The payload to vehicle weight
ratio is 1/20 for a car, while a typical single-track vehicle (i.e. motorcycle) has a payload
to vehicle weight ratio of 1/2, a factor of 10 better. Although automobiles are typically a
very popular choice for tens of millions of commuters everyday, it may be the most
energy inefficient among all man made transportation tools. Carrying of single individual
of 150 Ib by a vehicle of 3000 Ib is simply gross waste of precious energy resources. Due
to their large front profile and four wheels, cars consume much of their power by the
large aerodynamic drag force and large tire friction force at high speed. Cars are also
much wider than single-track vehicles and need a relatively wide road to operate. As a
result the road system occupies large land resource and is expensive to build for
reasonable flow capability.
Energy and time wasting, environment damaging traffic jams are frequent at large
metropolitans during rush hours. The parking lots also have to be large enough to
accommodate the vehicle sizes. All these contribute to large and wasteful land usage.
The excessive weights of vehicles are also dangerous. Dual-track vehicles take much
more brake force to stop them. In addition, dual-track vehicles also produce a much
larger impact force in an accident. The energy, environment and land resource issues
are compounding in the densely populated developing countries. The transportation
needs of tens of billions of people cannot be met by automobiles due to the large
burdens on the energy, environmental and land resources.
The tremendous reduction of body weight of a single-track vehicle makes its
engine much more effective in propelling it to a reasonable acceleration and speed even
with a much smaller engine power. Single-track vehicle can also be more energy efficient
in reduction of aerodynamic-drag, which is a major energy consumption contributor at
high speed. Since the front profile is much smaller than that of a typical car with an
elongated body, single track-vehicle has much smaller aerodynamic drag force.
Combining this with the fact that most single-track vehicles have two main wheels,
single-track vehicle can cruise at high speed with much reduced energy consumption
rate. They are also environmentally friendlier, use less road and parking resources and
release less greenhouse gas. But typically, single-track vehicles require extensive skill to
ride and are considerably more dangerous for inexperienced riders due to their intrinsic
instability. As a result, the mass population does not realize the potential for high fuel
efficiency, environmental safety and high performance of single-track vehicles.
Several types of light vehicles have been proposed to address the above issues
through either inline two wheels (i.e. motorcycle) with two supporting wheels or three
wheels (tricycle). The first type still requires rider to keep balance in normal riding
condition when the supporting wheels are retracted. Therefore, in general, it still requires
complex skill to ride it. The second type is a compromising solution between car and
motorcycle: It has three wheels to keep balance during slow or stop condition. At high
speed some them can balance the vehicle via active tilt control. For example, in U.S.
Pat. No. 5,765,840 (1998) to Braun from Daimler-Benz, U.S. Pat. No. 5,762,351 (1998)
to Soohoo and U.S. Pat. No. 4,903,857 (1990) to Klopfenstein. Europe and Japan also
granted quite a few patents on this area: 560,670 (European Patent Office) to Putin
(1995) and U.S. Pat. No. 5,039,073 to Matsuura from Honda motor (Japanese Patent).
This type of vehicles are self-balanced like cars. But they are heavier compare with
motorcycles, more expensive to make due to their energy drain hydraulic active tilt
control of the vehicle body and consume more power due to increasing of tire road
friction from the extra wheel. The self-balanced vehicle Segway uses two wheels (left
and right) with a dynamic balance to keep vehicle from falling forward or backward. (U.S.
Pat. No. 5,971,091 to Kamen et at). The major limitation is its speed and distance
between cnarges. Due to the centrifugal force during turn and high center of gravity,
Segway cannot go fast during turn. That is why its top speed is less than 20 mph.
SUMMARY OF INVENTION
Various methods, apparatuses, and systems in which a single-track vehicle has a
retractable auxiliary-support wheel assembly and a computer control system. In an
embodiment, the single-track vehicle has an elongated body. The retractable auxiliary-
support wheel assembly mounts on both sides of the elongated body. The computer
control system analyzes signals from one or more sensors to dynamically balance the
single-track vehicle.
BRIEF DESCRIPTION OF THE DRAWINGS
Non-limiting and non-exhaustive embodiments of the present invention are
described with reference to the following figures, wherein like reference numerals refer to
like parts throughout the various views unless otherwise specified.
FIG. 1 illustrates a side view of an example embodiment of an intelligent self-
balanced single-track vehicle.
FIG. 2 illustrates a block diagram of an embodiment of a computer controlled
steering system of self-balanced single-track vehicle.
FIG. 3 illustrates a block diagram of an embodiment of a control chart for the
control system with discrete time step, nonlinear closed loop optimal control.
FIG. 4a illustrates a flow chart of an embodiment of the vehicle control system.
FIG. 4b illustrates a block diagram of an embodiment of the steering
wheel/handle bar assembly of the user control.
FIG. 5 illustrates a block diagram of an embodiment of the vehicle steering
assembly.
FIG. 6 illustrates a block diagram of an embodiment of the auxiliary supporting
wheel assembly.
FIG. 7 illustrates a block diagram of an embodiment of one or two supporting
wheel assemblies in pre-lean condition.
FIG. 8 illustrates a block diagram of an embodiment of another use for the
supporting wheels.
FIG. 9 illustrates a block diagram of an embodiment of integrated control for
brake subsystem.
DRAWINGS-REFERENCE NUMERALS
1 microcomputer
2 Brushless steering motor
3 Electronic flat panel display
4 Steering wheel
5 Right supporting wheel
6 Aerodynamic actuators
7 Front brake
8 Rear brake
9 Right supporting wheel actuator
10 Planetary steering gear
11 Vehicle body
12 Front wheel
13 Rear wheel
14 Steering assembly
15 Integrated roll, yaw, pitch sensors
16 Front wheel speed sensor
17 Rear wheel speed sensor
18 Steering motor encoder
19 Planetary gear for steering
20 Steering wheel encoder
21 Steering wheel motor
22 Steering angle encoder
23 Left supporting wheel
24 Left supporting wheel motor
25 Right supporting wheel sensor
26 Left supporting wheel sensor
27 Right supporting wheel arm
28 Left supporting wheel arm
29 Body lean angle
30 Road torque sensor
31 Microcontroller for brake subsystem
32 Proximity sensor
33 Closed control loop
34 Optimal control
35 Random disturbance
36 Digital recorder
37 Digital IO
38 Brake lever
39 Linear quadratic regulator
40 Steering wheel gear
41 Three-phase inverter for driving brushless DC motor
42 Real time OS (RTOS)
43 Optimal trajectory of single-track vehicle
44 Air speed sensors
Various embodiments of methods, apparatuses, and systems of a seif-baianced
single-track vehicle are described herein. In the following description, some specific
details are given to provide a thorough understanding of embodiments of the invention.
One skilled in the relevant art will recognize, however, that the invention can be practiced
without one or more of the specific details, or with other methods, components,
algorithms, etc. In other instances, well-known structures, materials, or operations are
not shown or described in detail to avoid obscuring aspects of the invention.
DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS
Reference throughout this specification to "one embodiment" or "an embodiment"
means that a particular feature, structure, or characteristic described in connection with
the embodiment is included in at least one embodiment of the present invention. Thus,
the appearances of the phrases "in one embodiment" or "in an embodiment" in various
places throughout this specification are not necessarily all referring to the same
embodiment. Furthermore, the particular features, structures, or characteristics may be
combined in any suitable manner in one or more embodiments.
Figures are merely illustrative and are not necessarily drawn to scale or to the
exact shape. Furthermore, it is to be appreciated that the actual devices utilizing
principles of the invention may vary in shape, size, configuration, and the like, other than
what is shown in the figures, due to different implementation, equipment, design
tolerances, or other practical considerations that result in variations from one vehicle to
another.
In general, a single-track vehicle whose dynamic balance is maintained by a
computer controlled steering system is described. In an embodiment, the single-track
vehicle includes a front wheel and a rear wheel attached to a body frame and a computer
controlled steering motor^ The computer controlled steering system receives a user"s
road intention through a steering wheel/handle bar as an input. It combines the inputs
from a sensor subsystem for the state of variables of the vehicle to keep vehicle balance
and faithfully follows the rider"s intending path using an optimal control technique. The
system further improves the safety and performance through an integrated computer
control for braking subsystem, transmission, engine management and active
aerodynamic for a global optimal status. The vehicle system achieves high energy
efficiency and high maneuverability of a motorcycle, while freeing the rider from keeping
the vehicle balanced. The vehicle system provides the rider an easy, truly car-like driving
experience. The vehicle can be powered by gas, electric, hybrid or human sources. A
battery may exist to supply power to the computer control system and actuators.
In an embodiment, a computer-automated dynamic control system to calculates
the control of vehicle steering and leaning angles to achieve robust dynamic balance
equivalent to the function of an experienced motorcycle rider. In an embodiment of the
single-track vehicle, a rider can drive the single-track vehicle like a car: steering wheel
for steering and foot peddles for acceleration and brake. The computer will take over the
control of the vehicle balance just like an expert motorcycle rider. Computer control of a
vehicle may do even better than an experienced human rider can do because the
physical sensor subsystem may be vastly more sensitive and accurate in measuring the
vehicle dynamic status and computer controlled actuators are so much more precise,
fast and powerful in responding to any changes. The computer control may be much
more consistent than that of human control, and yield a vehicle with significantly
improved safety over traditional single-track vehicles (i.e. motorcycles).
Mechanical designs of ordinary single-track vehicles compromise vehicle
performance by the limitations of human control: limitations of the accuracy of sensing
the vehicle dynamic status, response time, and capable torque. New mechanical
designs, which are not bound by the restrictions of human limitations, can improve
vehicle performance significantly. The normal motorcycle front wheel, for example, is
significantly narrower than the rear wheel in order to reduce steering inertia to a human
controllable amount. As a result, the front wheel has less traction than the rear wheel.
This is a serious compromise between steering control and riding safety because during
braking, the front wheel produces about three times stopping power than the rear wheel
due to motorcycle dynamics. Because it combines narrower geometry with the need for
more stopping power, the front wheel is susceptible to losing traction and causing an
accident.
On the other hand, an embodiment of a computer controlled system can be
equipped with a powerful actuator for steering assembly so that the front wheel can be
made the same width as, or even wider than that of the rear wheel for a safer brake. The
integrated computer control system also optimizes overall performance in safety and
easy of use via control of an integrated brake system, supporting wheels, transmission
and motor management, replacing hands (steering by wire) and feet (computer
controlled supporting wheels subsystem for stability for slow or stopped vehicles). The
average rider can then enjoy the nimble handling and high fuel efficiency of a motorcycle
with stability and easy to drive characteristics of a high performance car.
The system may provide rider comfort. Since the rider will lean together with the
vehicle, the effective force (combination of gravitational and centrifugal forces) on the
rider is aligned with the supporting seat, just like in normal motorcycle riding, with zero
lateral force exerted on the rider. While in a car, centrifugal force throws drivers and
passengers left and right during turns in a winding road. Another safety benefit of single-
track vehicle is due to its light weight. During an accident that involves lightly weighted
single-track vehicles, the impact force is much smaller than that of heavy cars. Suppose
we have a dedicated lane for single-track vehicles, then road will become much safer
place.
During low speed maneuvers and some other maneuvers that require extra
stability during stopping and parking, the integrated computer control system can
automatically deploy, for example, up to two extra supporting wheels for more robust
balance. The system provides the rider with a car-like driving experience without having
to focus on balance under riding/driving conditions.
An embodiment of the computer control may provide a fuel efficient, low cost,
environmentally safe automated balance system for single-track vehicles, freeing riders
from focusing on balancing the vehicle at any speed under substantially any driving
condition.
An embodiment of the computer control may improve the vehicle in terms of
system level performance, safety and ease of operation through an integrated computer
control for steering, balancing, braking, transmission, active aerodynamics and auxiliary
supporting wheels.
An embodiment of the computer control may improve vehicle stability from
external disturbances such as sudden weight shift, wind gust, uneven road surface,
slippery patchs etc, at all speeds.
An embodiment of the computer control may improve brake effectiveness through
integrated control and providing automatic braking capability. The brake subsystem may
prevent wheel skidding, and keep the vehicle balanced during hard braking, avoiding
vehicle flip-over and fall. The subsystem also detects obstacles through sensors, then
activates brake automatically to avoid collision.
An embodiment of the computer control may provide stability for a single-track
vehicle when speed is too low for dynamic balance using, for example, two supporting
wheels, automatically controlled by the computer, which monitors the dynamic state
variables of the vehicle, so that riders don"t have to use their legs for supporting the
vehicle.
An embodiment of the computer control may push the performance envelope by
exploring the superior response characteristics of computer control compared with
human control: A computer control system may be more accurate and complete in
detecting the dynamic status of the vehicle and more precise and rapid in processing the
detected information and much more rapid in actuating the control. In this way the
mechanical design compromises commonly found in a singie-track vehicle can be
removed, resulting in vastly improved performance in mechanical handling of a single-
track vehicle system.
An embodiment of the computer control may further stabiize the single track
vehicle using active aerodynamic control. Similar to an airplane, an embodiment of the
vehicle has an active rudder and aileron control at high speed. The control activates a
rudder and ailerons according to the vehicle dynamic state to provide high performance
and stability.
An embodiment of the computer control may have a computer with optimal
control of the steering assembly using electric motor sensors, and supporting wheels for
single-track vehicles. The steering of the vehicle may be achieved by a computer
controlled electric motor. The computer, equiped with an optimal control algorithm,
balances and leads to the vehicle to the optimal path defined by the rider"s steering input.
The vehicle system may be further improved by integrating all other controls, i.e. braking
subsystem, motor management, supporting wheel subsystem etc, with the automatic
steering control.
FIG. 1 illustrates a side view of an example embodiment of an intelligent self-
balanced single-track vehicle.
Referring to FIG. 1, an embodiment of an intelligent vehicle may be composed of
vehicle body 11, a suspended front wheel 12 that is attached to the front steering
assembly 2, 10 and a rear wheel 13 that is attached to the body. The front steering
assembly 2, 10 and the body are attached with a steering axle 14. A microcomputer 1
serves as the brain for the vehicle balance: it measures the vehicle"s dynamic state with
set of sensors 15,16,17, computes the steering torque in real time to control the body
leaning angle and optimal trajectory according to user"s steering wheel 4 input for
maximum stability. The torque signal from the computer then executes electric motor 2 to
control the steering assembly. In some cases, for example, two supporting wheels 5, 23
can be automatically deployed by the computer to give extra stability at very slow speed,
stopping and starting, or parking conditions. At high speed, the two supporting wheels
may be retracted into the vehicle body and active aerodynamic actuators 6 improve
performance and stability of the vehicle via integrated computer control. The integrated
control is applicable to single-track vehicles driven by a combination of front wheel and
rear wheel, steering by front or rear wheel and powered by gas, electric motor and hybrid
motors.
The above description of illustrated embodiments of the invention, including what
is described in the abstract, is not intended to be exhaustive or to limit the invention to
the precise forms disclosed. While specific embodiments of, and examples for, the
invention are described herein for illustrative purposes, various equivalent modifications
are possible within the scope of the invention, as those skilled in the relevant art will
recognize.
These modifications can be made to the invention in light of the above detailed
description. The terms used in the following claims should not be construed to limit the
invention to the specific embodiments disclosed in the specification and the claims.
Rather, the scope of the invention is to be determined entirely by the following claims,
which are to be construed in accordance with established doctrines of claim
interpretation.
FIG. 2 illustrates a block diagram of an embodiment of a computer controlled
steering system of self-balanced single-track vehicle.
The auto balance, auto steering of the single-track vehicle can be achieved
through an optimal control technique. The control technique may include an optimal
control algorithm residing in a microcomputer or microcontroller, that calculates the multi-
body dynamics of the vehicle. It also includes a set of sensors 15, 16, 17, 22 for
measuring the state variables of the vehicle system, a force feedback steering wheel 4
for rider input, and a computer controlled electric motor 2 for exertion of torque on front
wheel steering assembly 14.
The sensor subsystem 15, 16, 17, 22 measures the dynamic state variables of
the vehicle system such as speed, steering, roll, yaw and pitch angles and their changing
rates, as well as friction, propelling and braking forces on front and rear wheels. The yaw
rate, roll rate and pitch rate can be measured using three orthogonal mounted
gyroscopes. The three gyroscope sensors are integrated with a microcontroller, three
MEMS accelerometers and three magnetometers to measure the three absolute angles
for roll, yaw and pitch as well their changing rates and is available commercially. The
other variables measured are front and back wheel speed 16 and 17 through two optical
encoders and steering angle through optical encoder 22. In an embodiment, the vehicle
uses two simpler incremental encoders to determine the angular rotation rates of the
wheels. In an embodiment, the vehicle measures the absolute value of the steering
angle. In an embodiment, the vehicle uses an absolute encoder to give the steering
wheel"s angle as well as the wheel"s changing rate. An electric potential meter can be
used to replace 20 for steering angle measurement with reduced accuracy, reliability and
more temperature drift. The random torque exerted on the front wheel from the road is
also measured for vehicle control by a force sensor 30 in FIG. 5 and realistic force
feedback to the steering wheel. The measured real time data from sensors streams into
the microcomputer for the calculation of the optimal steering angle, aiming to keep the
vehicle balanced and following the rider"s intended trajectory, defined by his/her steering
wheel/handle bar input. The feedback control loop of the optimal control algorithm
provides robust stability for all riding conditions including straight running, constant
turning, sudden swerving, lane changing and slaloming under braking or acceleration
conditions.
The dynamic state (i.e. speed, roll and yaw rate, steering angle, etc) of the
vehicle is displayed on a monitor 3 in front of the rider. In addition, our display also show
the information of what a normal vehicle displays: tachometer, speedometer, battery
voltage, temperature gauge, turn signal, high/low beam, odometer/tripmeter, fuel gauge
etc. Since a major portion of the vehicle may be controlled by computers, a flat panel
liquid crystal display (LCD), totally replaces the traditional mechanical analog hands. A
back lighted dot matrix super twisted nematic (STN) provides wide viewing angle, easily
readable under all weather light condition. LCD display offers benefit of reducing vehicle
weight, power consumption and system complexity compares with traditional display.
Its dynamic state vs. time may be stored in a non-volatile memory 36 for later
analysis and record keeping. Similar to a black box for aircraft, the digital memory
records continuously the most recent vehicle status (velocity, roll angle, roll rate, steering
angle, engine status, brake force etc.) and user inputs (i.e. steering wheel angle, brake
pedal pressure). The digital memory may have a "first in, first out" (FIFO) architecture.
With this implementation, the most recent data is substantially always stored for book
keeping. It can also be downloaded from vehicle digital IO 37 into off board computer for
later analysis. Digital 10 of the vehicle is also useful for system diagnostic and upgrade
firmware.
Referring to FIG. 1, the energy efficient computer controlled intelligent single-
track vehicle may include auxiliary supporting wheel assemblies and a computer control
system. The single-track vehicle may have an elongated body 11 that produces a small
aerodynamic drag. The auxiliary supporting wheel assemblies 5, 23 may mount on both
sides of the vehicle body for static and low speed balance. The computer control system
1 for automatic dynamic balance of the single-track vehicle may use a linear or non-
linear mathematical model of optimal control and an integrated control for the system
brake to keep the balance of the vehicle while slowing down. The computer control
system 1 for automatic dynamic balance of the single-track vehicle may also use active
aerodynamics to modify balancing at high speeds as well as high wind conditions. The
computer control system 1 for automatic dynamic balance of the single-track vehicle may
also control the auxiliary supporting wheels 5, 23 and transmission, engine management.
The single-track vehicle may also include a front wheel 12, and a rear wheel 13
that attaches to the vehicle body frame 11 through a swinging arm suspension, a front
assembly including a fork with telescope type suspension and a steering column 14. The
front assembly and the vehicle body are attached at a revolute joint through the steering
column. The steering and power can be controlled through different combinations of the
front and rear wheels.
The single-track intelligent vehicle uses human-machine interaction and is
designed to feel similar to driving a car. The single-track intelligent vehicle has a steering
wheel 4 for vehicle direction control, foot pedals for acceleration, brakes, clutch (for
manual transmission only), and a right hand operated handle for gear shift (for automatic
or manual transmission).
The computer control system for automatic dynamic balance and system
integrated control may have control software for sensing, processing and actuating of
optimal control for the single-track vehicle, dynamic balancing, integrated braking,
acceleration, transmission, engine control and auxiliary supporting wheels. The software
may be executed by one or more digital microcomputers, ASICs, and/or microcontrollers.
In an embodiment, the software may be a multi-task real time operation system for
managing the software execution that allocates the CPU and memory resource for
various controlling tasks. A steering wheel 4 for user provides an input signal as to the
desired direction into the controlling computer. A steering wheel 4 may have force
feedback to reflect the real road to front wheel interaction.
A sensor subsystem 15, 16, 17 measure vehicle dynamic states and vehicle-
environment interactions and provides input signals to the computer control system for
automatic dynamic balance. An electric motor 2 receives a control signal from the
computer control system for automatic dynamic balance to turn the steering column. A
set of actuators 9, 21 receive a control signal from the computer control system to
execute the control signals for auxiliary supporting wheels.
The control software uses control models that are based on multi-body dynamics
of the realistic vehicle physical descriptions and optimal control 34.
An advantage of the control software is the software calculates dynamic
balancing for the vehicle with optimal control for the current use conditions, integrates
that determination with feed back to optimize the vehicles stability, and follows the riders
desired direction from the steering wheel input.
In an embodiment, the control software may include control models that are
based on neural network such as Cerebella Model Articulated Control (CMAC) with
adaptive and learning capabilities. In an embodiment, the control software may include
control models that are based on fuzzy logic.
Thus, the computer control system receives input signals from sensors
measuring the vehicle"s dynamic status, then the computer processes the sensor"s and
user"s inputs to control actuators to form a closed loop 33 control. The computer control
system may achieve robust stability, even under the influence of random perturbation
such as sudden weight shift, sudden wind gust, uneven road surface, slippery road
patches.
in an embodiment, the computer control system may include an integrated control
which can use different processing models ranging from centralized computing via a
single powerful processor to distributed processing via many interconnected processors,
each one dedicated to one or more specific controlling tasks. The computer control
system may include computer hardware which contains a digital signal process in order
to obtain efficient dynamic calculations for added control. The computer control system
may perform a self-test on the computer hardware, memory, sensors and actuators.
The sensor subsystem may include the status of the vehicle which is measured
by many sensors 15, 16, 17, gyroscopes for body pitch rate, yaw rate, and rolling rate,
inclinometers for rolling angle, force sensors for steering torque and brake torque, speed
sensors, slip sensors for wheel locking during brake.
The computer controlling the integrated brake system may direct the brake
actuators 7, 8 with optimal force to front and back wheels to stop the vehicle in a
controlled manner. The integrated brake system may include the brake actuators 7, 8 of
front and back wheels that are linked with the controlling computer and sensor
subsystem to prevent the wheels from locking or skidding as well as prevent the vehicle
from loss of balance and flipping over. The integrated brake system may detect potential
collisions in the vehicle"s path through proximity sensors 32 and a computed trajectory,
and the computer issues a control signal to activate the brakes and steers the vehicle
away for automatic collision avoidance.
The computer control system may use a control algorithm for the deployment of
the auxiliary supporting wheels 5, 23 at times such as low speed, when stopped, or when
the dynamic balancing needs additional fixed balancing support. The auxiliary supporting
wheels couple to computer controlled arms 27, 28 which are capable of being set at
different angles. The linkage to the system computer so that the arm angles at the left
and right side of the vehicle body can be set according to optimal values of the vehicle
dynamic states, angle position sensors for computer servo control, and a fail safe
mechanism for deployment of the supporting wheels in case the control system fails.
The control algorithm for the supporting wheel sends signals to the supporting
wheel actuators 9, 21 with optimal deployment angles, reads angle sensor feedback to
confirm that the correct angles have been set and that the supporting wheels have been
deployed or retracted according to the system dynamic balance needs. In the control
algorithm for the supporting wheel, when the vehicle stops on an uneven surface, then
the computer senses the surface condition and deploys the supporting wheels 5, 23 at
calculated angles to keep the vehicle body upright. When the rider stops the vehicle
before an immediate sharp turn, the control algorithm for the supporting wheel
communicates to the computer to actuate the supporting wheel arms to create a pre-lean
in the direction of the turn before or when the vehicle starts to move. The auxiliary
supporting wheels system may include a mechanism capable of fast deployment (during
braking) and slower retraction speed (during start).
The integrated optimal control system may include an integrated active
aerodynamic control that directs the aerodynamic actuators 6 for improving stability and
performance according to the vehicle dynamic states, at high speed. The aerodynamic
control allows the computer to take input from the vehicle dynamic status (speed, yaw
rate, roll rate) and actuates a rudder and aileron control 6 to further stabilize the vehicle
at high speeds and during turns. The integrated optimal control system uses a control
algorithm to compute the optimal combination of engine speed and transmission ratio for
vehicle performance and fuel consumption.
The integrated optimal control system may include a display 3 that shows the
state of the vehicle, such as roll angle, steering angle, vehicle speed, engine rate,
steering angle, transmission status, and supporting wheel status, using a flat panel LCD
display. The display 3 shows the actual rolling angle vs. the vehicle rolling angle limit due
to measured road traction and vehicle geometry, so that the rider can be informed to ride
within the vehicle"s limits in addition to the display may illustrate normal vehicle
information such as engine speed, vehicle speed, battery voltage, and temperature. On
the display, when the rider pushes the vehicle control too close to the vehicle"s hard limit,
the system issues a warning in terms of an audible signal and flashes a message on the
display 3. (Example: sharp turn ahead, too fast speed).
The integrated optimal control system uses a safety control program for safety
equipment, such as deployment of airbag, active restraints, collision sensors 32 which
are linked to the controlling computer 1, and actuators for the safety equipment 7, 8.
The integrated optimal control system may include a non-volatile memory that
continuously stores the most recent vehicle system status and user controls for a fixed
period of time, so that the vehicle status and user control can be analyzed later for
debugging and accident investigation.
The integrated optimal control system may include a digital IO system that
performs input and output to outside computers, for firmware upgrade, system
diagnostics and off-vehicle data analysis.
In an embodiment, the physical design of the single-track vehicle hardware is
optimized for computer control characteristics, instead of human rider interaction. The
single-track vehicle may include a solid enclosure with doors or hatch that can help
provide protection against collision, weather conditions and wind.
FIG. 3 illustrates a block diagram of an embodiment of the control chart for the
control system with discrete time step, nonlinear closed loop optimal control.
In an embodiment, the intelligence of the vehicle, in part, come from its computer
optimal control algorithm (FIG. 3). Optimal control assists in mainataining stability during
operation by use of closed control loop to make the vehicle stable. The vehicle may have
a dynamical system described by a set of coupled non-linear second order differential
algebraic equations (DAEs). The vehicle may be controlled so that it travels close to
user-defined trajectories. The auto-balanced single-track vehicle achieves an optimal
control with random disturbances 35 and statistical noise through a nonlinear control
method. Motorcycle dynamic states can be represented by its yaw, roll and pitch angles,
rotational speeds of wheels, steering angle and front and rear suspension deflections.
From the dynamic behavior of multi-body dynamics of the vehicle, a set of coupled
nonlinear second order differential algebraic equations for motorcycle state variables can
be obtained. This set of DAEs determines the behaviors of the vehicle system. And they
are called dynamic equations. Based on the dynamic equations, the microcontroller
constructs an optimal trajectory 43 aiming to keep the vehicle stable, at the same time
optimally following the rider-defined trajectory 34. Since the system is highly nonlinear, it
is difficult to compute its optimal trajectory due to the restriction of real time and
computer resources. Instead the microcontroller divides the system states into several
smaller domains and linearizes the system using discrete time steps. The nonlinear
optimal control problem becomes several linear quadratic regulators (LQR) 39, each for
a portion of domain. The goal of the control system is to minimize a penalty function,
which is designed to keep the vehicle stable and follow the rider"s intended path as
closely as possible. The feedback loop 33 of the control is very effective in reducing the
impact of random perturbation from road imperfection, wind, modeling and numerical
error and parameter inaccuracies. In an embodiment, the single-track vehicle uses an
optimal control method having balance of inverted pendulum.
Other control methods, such as an artificial neural network (ANN), Cerebella
Model Articulated Control (CW1AC) in particular, and fuzzy control can a\so be used to
replace optimal control method to achieve similar objectives. The effectiveness of an
ANN controller does not depend on detailed and accurate mechanic model of the
vehicle. This can be a major benefit when the system is too complex to build an accurate
model. An additional benefit of ANN is its adaptivity. The control behavior can be easily
and quickly tuned to give optimal response under changing conditions. One example of it
is weight shift of the vehicle. Suppose a load is shifted from one portion of the vehicle to
other, the center of gravity changes. That impacts the vehicle dynamic behavior. By
being able to adapt the change, the vehicle can quickly tune itself to the optimal stable
dynamic states. The vehicle"s dynamic behavior may depend upon training data
The vehicle computer control performs many control tasks (i.e. dynamic balance,
supporting wheel control, active aerodynamics, integrated brake etc.) with a real time
operation system (RTOS) 42. The main purpose of RTOS is to prioritize and manage
CPU and memory resources for different tasks. RTOS may employ a guaranteed time
response so that higher priority tasks are done first under a required time schedule. For
example, the integrate brake control and dynamic balance would be assigned as a
highest priority task.
FIG. 4a illustrates a flow chart of an embodiment of the vehicle control system.
In block 401 the microcomputer calibrates the system. The calibration includes a home
cycle of all encoders and absolute measurement using incremental encoders. The
microcomputer also does a self-test for computer system, wire connections, sensors,
and actuators. If the self-test is not successful the microcomputer aborts the system test
and calls for service in block 402. In block 403, If the test is successful, the
microcomputer reads steering wheel position from rider through an optical encoder. In
block 404 the microcomputer computes the user intended trajectory using his/her
steering information. In block 405, the microcomputer reads vehicle dynamic state such
as roll, yaw and pitch angles and rates, vehicle velocity, vehicle"s actual steering angle.
The vehicle state then classified and assign to a domain in block 406. A specific linear
quadratic regulator is called in block 407 where the microcomputer computes an optimal
control and closed loop feedback stabilization as in FIG. 3. In block 408, the
microcomputer delays until it is time for next time step synchronization and calculation.
Then the microcomputer check the rider power switch in block 409. If user turns off
his/her vehicle, the microcomputer will call stop and parking sequence in block 410,
which evolves slowdown the vehicle, lower the supporting wheels, then turn off computer
control system and vehicle.
FIG. 4b illustrates a block diagram of an embodiment of the steering
wheel/handle bar assembly of the user control. [0113] The steering whee\ assembly may
be mechanically isolated from the steering assembly (FIG. 4b). It communicates only
with the controlling computer, transmitting the rider"s desire for his/her intended path and
sending a signal for road generated force feedback to the rider. Rider directional input in
real time is geared up and digitized through an optical encoder 20 before been fed into
the computer for control signal calculation. Encoder is a device that translates the
steering shaft rotation motion into an electric signal. The optical encoder 20 offers great
reliability and accuracy used by vehicle control. The steering subsystem may behave like
a car"s steering so that many riders who are already familiar with driving a car can
instantly feel comfort in riding the vehicle. Since a typical car steering wheel can turn
from -540 to +540 degree, the vehicle"s steering wheel turn"s more than 360 degree and
the encoder has to be capable of encoding multi-turn signals. Since our steering wheel is
not connected to a steering assembly and front wheel mechanically, the rider cannot feel
random road force exerted on the front wheel. A force feedback may be added to the
steering assembly to help the user feel like he or she is driving a conventional vehicle.
The force feedback is created by an electric motor 21 and gear assembly. The motor
exerts force to the steering wheel according to the road force measured by sensor 30 in
FIG. 5 mounted on the steering assembly.
FIG. 5 illustrates a block diagram of an embodiment of the vehicle steering
assembly.
The steering assembly (FIG. 5) may be controlled by a computer through a
brushless electric motor 2 and planetary gears 19 for matching the desired torque and
speed. The brushless DC motor is excellent in terms of reliability, efficiency and size
compared with other types of electric motor. For example, 33 Watts of peak power may
be sufficient for motorcycle steering. A brushless motor uses a speed sensor to generate
the driving sinusoidal voltage to it"s wiring connectors in the correct timing sequence. The
actual steering angle is measured by an optical encode 22 mounted on the steering axle
14. Planetary gear reduces the normal speed of DC motor from typical 3000 rpm down to
30 rpm of typical vehicle steering speed and increases its steering torque at the same
time.
Planetary gear offers high reliability under large steering torque. The controlling
computer continuously reads the encoder signal 22 for steering angle and outputs an
optimal control signal sequence to the steering motor and gear assembly for the proper
torque over real time to achieve the desired optimal path and state control. The motor
and gear assembly then apply torque to steering axle 14 to achieve actual steering
action.
FIG. 6 illustrates a block diagram of an embodiment of tne auxiliary supporting
wheel assembly.
When the vehicle is too slow to be dynamically balanced, or during parking, the
controlling computer automatically deploys one or more supporting wheete 5, 23 in GIG.
6 mounted along each side of the vehicle for keeping balance. The one or more
independently controlled wheels can also be used during sharp U-turns, or during high
speed turning for extra stability. Each of the supporting wheels has force sensors 25, 25
for feedback control into the main computer, and independent motors 9, 24 to guarantee
the vehicle stability and that the main force is still distributed to front and rear wheels by
adjusting supporting angle and steering angle. The motors 9, 24 also have built-in
encoders to feed back the actual angles of the supporting wheel arms 27, 28 into the
controlling computer.
FIG. 7 illustrates a block diagram of an embodiment of one or two supporting
wheel assemblies in pre-lean condition.
The vehicle body needs to lean at a small angle according to the steering wheel
position during stops for immediate turning, resulting in a more optimal turning trajectory
after the stop (FIG. 7). The computer system achieves this by reading the steering wheel
position from steering wheel encoder 20, computing an optimal lean angle, and actuating
supporting wheel motors 9, 21 to produce the correct amount of body lean angle 29.
FIG. 8 illustrates a block diagram of an embodiment of another use for the
supporting wheels.
The arms 27, 29 of the supporting wheels may be independently controlled by the
microcomputer to any angle. This capability can be useful for maintaining balance when
the vehicie is parked on an uneven surface (FIG. 8). The computer reads the tilt
information from an inclinometer mounted on the vehicle body 15, computes the
necessary angles of the supporting arms 27, 28 and instructs the actuators 9, 24 to
achieve an upright position even when the parking lot is uneven.
FlG. 9 illustrates a block diagram of an embodiment of integrated control for
brake subsystem.
During braking, the system goes one step further than anti-lock brakes. The
microcomputer senses the wheel spin status from the sensors 16, 17 in FIG, 1 mounted
on front and rear wheels, and senses the vehicle body status for possible flip-over (pitch
sensor in sensor group 15 In FJG, 1) or fall (inclinometer 15 in sensor group FIG. 1)
during strong braking. The independent microcontroller 31 for brake control and the main
computer together form a distributed control system. The skidding sensors mounted
directly on front and rear wheels send signais directly to brake controller 31 and it directly
controls the brake actuators for front and rear wheels for fast execution of an ant-lock
function. At the same time main computer 1, which has the knowledge of vehicle status
such as piteh angle, ntf angle and steering ang/e, computes the optimal trajectory and
maximum braking forces for front and rear wheels- that will not destroy vehicle balance. II
communicates the information to the brake controller for activating the brakes. Main
computer 1 also generates an optimal trajectory under the brake condition and directs
the steering assembly 2 to follow it. The main computer can also deploy supporting
wheels with calculated angles in case the system balance cannot be met by dynamic
balance atone. In this way, the vehicle can achieve the shortest possible stopping
distance, in the direction intended by the rider At the same time the vehicle is still kept in
a stable status by dynamic balance and possibly with up to two side supporting wheels
The vehicle can be equipped with an endosuire, air conditioning, and audio
system, just like cars, They offer comfort under different weather condition and crash
protection.
The computer controlled self-balanced motorcycle can inherit all the benefits of
single-track vehicle: power consumption reduction, greenhouse gas reduction, nimble
rnaneuverability, great saving on road and parking resources, and is cheap to make and
maintain compare with automobile At the same time it offers the aability and simply to
operate equally to 4 wheel passenger cars. If widely adapted it will have a large positive
impact on environment, road and parking resource and oil usage for major metropolitan
area and densely populated third world countries.
The above description of illustrated embodiments of the invention, including what
is described in the abstract, is not intended to be exhaustive or to limit the invention to
the precise forms disclosed. While specific embodiments of, and examples for, the
invention are described herein for illustrative purposes, various equivalent modifications
are possible within the scope of the invention, as those skilled in the relevant art will
recognize. These modifications can be made to the invention in light of the above
detailed description. For example, most electronic hardware and computer chip
operations can be emulated by software. The terms used in the following claims should
not be construed to limit the invention to the specific embodiments disclosed in the
specification and the claims. Rather, the scope of the invention is to be determined
entirely by the following claims, which are to be construed in accordance with
established doctrines of claim interpretation.
WE CLAIM
1 An apparatus comprising:
a single track vehide with arv elongated body (11);and
a computer control system (1) to analyze signals from one or more sensors to
dynamically balance the single-track vehicle, characterised in that the computer central
system (1) dynamically balances the vehicle by controlling a steering assembly (14) of the
vehicle by steering actuator.
2 The apparatus as claimed in claim \, wherein a first sensor comprises a gyroscope.
3. The apparatus as claimed in claim 1, wherein a first sensor comprises an gccelerometer
4. The apparatus as claimed in claim 1, wherein a first sensor comprises a magnetometer.
5 The apparatus as claimed in claim 1, wherein the computer control system(1) balances
the single-track vehicle based upon an optimal control algorithm.
6 The apparatus as claimed in claim 1, optionally comprising: a computer controlled braking
subsystem(31) integrated with the computer controlled balance system(1) to maintain
balance on the single-track vehicle while braking
7. The apparatus as claimed in claim 6, wherein the computer controlled braking subsystem
(31) direct the operation of one or more brake actuators (7.8) on 3 front wheel (12,13) and
a back wheel based upon optima) force calculations.
8 The apparatus as claimed in claim 1, optionally comprising an electric motor (21)
controlled by the computer controlled steering system, wherein a sensor detects a position
of the steering wheel (4) of the steering assembly (14) to provide an input signal into the
computer controlled peering system and a control that from the computer controlled
steering system controls a steering column of said steering assembly (14).
9. The apparatus as claimed in claim 1, optionally comprising: a rudder; and an aileron, the
computer control system to control position and alignment of the rudder and the aileron to
further stabilize the single-track vehicle.
10. The apparatus as claimed in claim 1, wherein the computer control system to control
steering and leaning angles of the single-track vehicle based upon the signals from the one
or more sensors.
11. The apparatus as claimed in claim 1, wherein the vehicle has a retractable auxiliary
support wheel assembly (14) and said assembly is attached via the computer control
system.
12. The apparatus as claimed in claim 11, wherein the computer control system to receive
an incline surface condition from the one or more sensors and to deploy the retractable
auxiliary supporting wheel assembly at calculated angles to keep the vehicle body upright.
13. A method, comprising: dynamically balancing a single-track vehicle using a computer
control system (1) based upon receiving and analyzing input signals from one or more
sensors; and using said computer control system to control steering and leaning angles of
the single-track vehicle based upon the signals from one or more sensors.
14. The method as claimed in claim 13, optionally comprising: controlling operation of one or
more brake actuators (7,8) on a front wheel and a back wheel (12,13) of the vehicle based
upon optimal force calculations.
15. The method as claimed in claim 13, optionally comprising: lowering an auxiliary
supporting wheel assembly (14) based upon a sensed dynamic state of the single-track
vehicle.
16. The method as claimed in claim 13, optionally comprising: altering an angle of an
auxiliary supporting wheel assembly based upon a sensed incline of a surface the single-
track vehicle is on.
17. The apparatus as claimed in claim 13, optionally comprising: means for lowering an
auxiliary supporting wheel assembly (14) based upon a sensed speed of the single-track
vehicle.
18. The apparatus as claimed in claim 13, optionally comprising: means for altering an
angle of an auxiliary supporting wheel assembly (14) based upon a sensed incline of a
surface the single-track vehicle is on.
Various methods, apparatuses, and systems in which a single-track vehicle has a
retractable auxiliary-support wheel assembly and a computer control system. In an
embodiment, the single-track vehicle has an elongated body. The retractable auxiliary-
support wheel assembly mounts on both sides of the elongated body. The computer
control system analyzes signals from one or more sensors to dynamically balance the
single-track vehicle.

Documents:

537-kolnp-2005-granted-abstract.pdf

537-kolnp-2005-granted-claims.pdf

537-kolnp-2005-granted-correspondence.pdf

537-kolnp-2005-granted-description (complete).pdf

537-kolnp-2005-granted-drawings.pdf

537-kolnp-2005-granted-examination report.pdf

537-kolnp-2005-granted-form 1.pdf

537-kolnp-2005-granted-form 18.pdf

537-kolnp-2005-granted-form 2.pdf

537-kolnp-2005-granted-form 3.pdf

537-kolnp-2005-granted-form 5.pdf

537-kolnp-2005-granted-letter patent.pdf

537-kolnp-2005-granted-pa.pdf

537-kolnp-2005-granted-reply to examination report.pdf

537-kolnp-2005-granted-specification.pdf


Patent Number 213982
Indian Patent Application Number 537/KOLNP/2005
PG Journal Number 04/2008
Publication Date 25-Jan-2008
Grant Date 23-Jan-2008
Date of Filing 31-Mar-2005
Name of Patentee EVERTEQ
Applicant Address 1185 KEYSTONE COURT SAN JOSE, CALIFIRNIA 95132 USA.
Inventors:
# Inventor's Name Inventor's Address
1 EVERETT,X,WANG 1185 KEYSTONE COURT SAN JOSE, CALIFIRNIA 95132 USA
PCT International Classification Number B62D 61/04
PCT International Application Number PCT/US2002/035335
PCT International Filing date 2003-11-05
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 10/299,612 2002-11-18 U.S.A.