Title of Invention

'A REAL TIME FLIGHT MONITORING SYSTEM'

Abstract

The present invention, is a state —o f — art res1 time f1ight monitoring system, which is capable of providing unified, coordinated and accurate flight safety decision related to airborne vehicles in a real time manner using all the necessary flight date. The flight monitoring system of the present invention is particularly useful for monitoring the flight of unmanned airborne vehicles, which are under development. The flight monitoring system fo the present invention is capable of providing real time flight safety decision on a single video display based on information of trajectory data and strack status data. The real time flight trajectory data are obtained from various instruments like ground-based radars, electro-optic trackign instruments, and on-board sensors, e.g. inertial navigation system and global positioning systems. In addition to this the flight health parameters (chamber pressure, body rates etc.) are received through telemetry system. The system is hightly compact, portable, easier to implement and cheaper to make and it can also be used s s a simultating system for training purposes. Further, it can be interfaced with different haridware (e.g. Personal Computer, Workstation etc.) and operating systems (like UNIX, Windows 95, Windows NT etc.). The aalgorithm of the system is designed and coded in such a way that it is easy to understand, handle, maintain and update. The system of the present invention utilises new technologies in the field of data processing, taret tracking and estimation , dats sssociation , artificial intelligence, high speed tracking, high speed computer system etc:,

Full Text

Field of Invention: This invention relates to a real time flight monitoring systems for airborne vehicles, particularly to the field of flight monitoring systems for non-passenger airborne vehicles, which are under development. Prior Art: The launch of airborne vehicles requires monitoring, at the ground station, the conformity of the performance of the airborne vehicle with the expected one in order to protect human life and property in case of any failure. This is particularly important for launch of non-passenger airborne vehicles,. which are under development. By analyzing the real time position and impact point data of the airborne vehicle, a decision can be taken at the ground station whether to continue or to terminate the flight of the errant non-passenger airborne vehicle within a very short time. The process of decision making should be very fast (within 3-4 sec) and accurate, as any error or delay in such crucial decision may lead to catastrophic effect to human life and property or termination of a high cost serviceable vehicle. In general, following sets of data are generated for the monitoring of the flight of any airborne vehicle at the ground station: (i) The real time flight trajectory data (ii) The flight vehicle health parameter data (iii) The ground tracking instruments status data The real time flight trajectory data is required to ensure that the airborne vehicle stays on the predefined flight trajectory and does not deviate from it during the flight time. Normally, the flight pattern of the airborne vehicle is monitored with the help of a radar, electro-optic tracking system (EOTS) as well as on-board inertial navigation system (INS) and differential global positioning systems. A flight trajectory display system is required to display the above parameters for visualization of the events in real time on the ground station for performance evaluation and safety decision making. The trajectory display system displays the various instruments trajectory in a nominal background plot in different colours. The trajectory data are received from central computer after filtering and processing the data received from various instruments like ground based radars, EOTS, telemetry and on-board inertial navigation and global positioning systems. The airborne vehicle health parameter data is required to ensure that all the on board parameters are within the permissible limit and the vehicle is operating under the normal manner. This set of data essentially comprises combustion chamber temperature and pressure, pitch yaw and roll behavior and other on board events. This set of data is generated through a variety of sensors, which are positioned on board and are transmitted from the vehicle to the ground station via radio waves for real time monitoring. The on-board parameter display system comprises on INS velocity profile display on background nominal velocity profile. On-board computer time, chamber pressures, flight body rates (yaw, pitch and roll) behaviors and other on-board events. Additionally, one more of set of data is required to be monitored on a continuous manner. This set of data is generated for monitoring the tracking status of the ground tracking instruments. This set of data, displayed in another monitor, ensures that the ground based tracking instruments are functioning in a desired fashion. The ground-tracking-system-status-display unit provides the details of the tracking status of the tracking instruments like radar, EOTS telemetry etc. The parameters displayed are range, azimuth and altitude of the flight vehicle at any instant of time as well as track loss, re-acquisition of the trajectory of any tracking instruments and whether the track is auto or manual at any time instant. The following main critical areas are involved in any real time flight monitoring system development for an airborne vehicle. (i) Clear understanding of flight safety monitoring criteria and contingencies in view of geographical area and flight corridor restrictions (ii) Understanding of in-flight vehicle dynamics and subsystem functioning and cumulative effect of subsystem failure on final trajectory output. (iii) Understanding of various tracking sensors with their capabilities and limitations (iv) Acquisition of expert's exact knowledge and generation of knowledge base (v) Implementation of knowledge base along with inferencing scheme in real time (vi) Study and implementation of different filtering method and technique (vii) Study and implementation of similar and dissimilar sensor fusion methods and techniques for obtaining best estimated data for decision making. (viii) Design and implementation of graphic display of consolidated flight safety decision along with audio alarm. The are various systems, known in the prior art, for monitoring the flight of airborne vehicles. The conventional systems, known in the art, basically comprise of graphical display of position, impact point and critical health parameters of the vehicle on the ground station, which has to be monitored visually and analysed mentally in real time to take flight safety decision in real time. The conventional flight Safety Network is shown in flow chart. 1 Typically, these data pertaining to the position, attitude, flight heading, instrument track status, safety aspects etc of the flight vehicle are displayed on different video monitors which are analysed to determine whether the airborne vehicle is on the pre-determine path or not. In case of any deviation from the predetermined flight trajectory and thereby threat to any security, the flight itself may be aborted. But the process of decision making has to be very fast and accurate. Any delay in such a crucial decision may lead to catastrophic effect to human life and property in addition to the cost of air borne vehicle itself. However, the conventional systems, available in the prior art, for monitoring these three sets of data suffer from several disadvantages. The main disadvantage of the conventional systems, known in the prior art, for monitoring the flight of airborne vehicles, is that in these systems different sets of data are displayed on different video monitors and these are not integrated at one , place thereby making the task of monitoring and analysing these sets of data very tedious. Another, disadvantage of the conventional systems, known in the prior art, for monitoring the flight of airborne vehicles is that in these systems, nhe response time for the making a decision regarding continuation of the flight is higher as one has to study data at different video terminals on the ground station. Yet further disadvantage of the conventional systems, known in the prior art, for monitoring the flight of airborne vehicles is that human bias, fatigue and panic may effect these systems. Yet another disadvantage of the conventional systems, known in the prior art, for monitoring the flight of airborne vehicles is that(!hese systems are prone to the wrong interpretation of data which may arise due to the low resolution computer display screens, N Objects of the Invention: Primary object of the invention is to provide a real time flight monitoring system for airborne vehicles, which is capable of displaying/real time flight safety decision based on the all critical information pertaining to the airborne vehicle at one place.) Another object of the invention is to provide a real time flight monitoring system for airborne vehicles, which meets the real time requirement in the sense that the decision regarding the safety of the flight can be made in a very short span of time. Yet another object of the invention is to provide a real time flight monitoring system for airborne vehicles, which is immune from human bias and fatigue. Yet further object of the invention is to provide a real time flight monitoring system for airborne vehicles, which is capable of providing error free and fast automated flight safety decision without human intervention. Still further object of the invention is to provide a real time flight monitoring system for airborne vehicles, which is free from inaccurate sensor data interpretation arising from the low resolution of graphic display terminal. Yet further object of the invention is to provide real time flight monitoring system for airborne vehicles, which can be interfaced with different hardware (like personal computer , workstation etc.) and operating systems (like UNIX, Windows 95, Windows NT etc.). Still further object of the invention is to provide real time flight monitoring system for airborne vehicles, which is easy to understand, handle, maintain and update due to the specially designed and coded algorithm. Fig. 1 is a block diagram of the real time flight monitoring system of the present invention; Fig. 2 represents block diagram of the trajectory data acquisition unit; Fig. 3 represents block diagram of the trajectory data acquisition unit; Fig. 4 represents block diagram of the decision making unit. Fig. 5 represents block diagram of real-time-decision-display unit Fig. 6 represents the sample of flight safety display diagram Description of the Invention with Respect to the drawings: Referring to Fig. 1, the real time flight monitoring system of the present invention mainly comprises of five sub-units namely: trajectory data acquisition unit (1), data processing, filtering and fusion unit (2) decision making unit (3), decision output display unit (4) and simulation/post flight analysis unit (5) The trajectory data acquisition unit (1) receives data from various ground based sensors (like Radar, Electro-optical tracking systems etc.) (A) as well as on-board sensors like Inertial Navigation System (INS), Differential Global Positioning System (DGPS) data, (B) validates the data and extract trajectory information in Cartesian coordinated system from angular data (e.g. from Telemetry angular data, EOT data etc.). The data processing, filtering and fusion unit receives the data from the data acquisition unit and processes the valid data and fuses them using Kalman filter fusion algorithm, taking into account the statistics of the measurement noise, process noise and tracking instrument characteristics. This unit sends three channels of filtered and used data to the decision making unit (3) for further processing. After getting all three fused sensor data and health data from above module, the decision making unit computes different flight safety parameters (e.g. critical angle margin, instantaneous impact point margin etc.) for each of the three channels and then processes the rule base for providing flight safety decision. Decision output display unit provides interactive graphic display output as well as audio alarm as output to flight safety monitoring personnel. The graphic display provides main Flight Safety Decision together with alphanumeric displays explanation for the decision) for Flight Safety Decision making. Simulation/Post Flight Analysis unit (5) is used to validate the system before actual real time use for different flight trajectory condition as well as tracking instrument status. Referring to Fig. 2, the trajectory data acquisition Unit (1) comprises of Real Time Data Acquisition Unit (6), angular data trajectory extraction unit (7) and Data Validation unit (8). The real time data acquisition unit (6) receives the raw sensor data from the data source in a certain format through UDP/IP protocol and socket programming. Angular data trajectory extraction unit (7) extracts x, y, z coordinate data (in Cartesian coordinate) using triangulation method from telemetry azimuth, elevation and base distance data. The least Square method (EOTS) angular data also. The Data Validation unit (8) qualifies the acquired sensor data based on instruments tracking status. Referring to Fig.3, the data processing, filtering and fusion unit (2) fuses different measuring instrument track data based on the fusion algorithm. It comprises Kalman dynamic tracking filter (10) and three multi-sensor data fusion module (9). The Caiman dynamic tracking filter (10) provides accurate trajectory estimate by taking into account measurement noise, process noise and state estimation error. It is capable of predicting for 4 seconds for each tracking instrument in case of track loss. This filtering algorithm is implemented by using UD-factored Kalman filter algorithm, which is very stable and efficient for real time use. The UD factor from of Kalman filter retains the positive definiteness of the state error covariance algorithm (which is the basic requirement of Kalman filter) and thus avoids the problem of filter divergence due to loss of symmetry and positive definiteness of error covariance matrices. The algorithm is efficient also in the sense of requirement of less computation. No matrix inversion and less storage space of required in comparison to normal rect Kalman filter implementation and thus fulfills the real time requirement. Multi-sensor data fusion module (9) aims at providing trajectory information (position, velocity and acceleration of flight vehicle) in totality by taking into account different instrument's tracking capability, viz., range of tracking, mode of tracking (optical/ thermal/radio wave etc.), spatial dimension of tracking (e.g. range, range rate etc.), measurement accuracy, etc. Using covariance-based Fusion algorithm, it evaluates three trajectory tracks from the multiple sensor (about 10-8 sensors) trajectory - two trajectory based on fused ground based instruments and one fused on-board instruments and outputs the above fused trajectory data to data integration and decision unit. The three trajectory fusion sub-modules are as follows: (i) Fusion module (11): The fusion module (11) provides trajectory estimation by track to track and track extraction fusion and priority logic. The priority logic is applied on the basis of accuracy, range and availability of the sensor track in real time. The fused data (a) is sent to DSS through UDP/IP protocol in a particular packet format. The data packet contains time, position, velocity, data validity, sensor identity, fusion identity, filter status information. (ii) Fusion Module (12): The fusion module (12) is for the ground based similar sensors. In this case two similar ground based radars are fused. The fused data (b) is sent to DSS through UDP/IP Protocol. The data packet contains time, position, velocity, data validity, sensor identity, fusion identity and filter status information. (iii) Fusion Module (13): The fusion module (13) provides fusion of on-boar sensors (INS and GPS). In this case the Inertial Navigation System (INS) and Global Positioning System (GPS) are fused with proper time synchronisation and the data (c) is sent to DSS through UDP/IP Protocol. The data packet contains time, position, velocity, data validity, sensor identity, fusion identity and filter status information. The above mentioned sensor fusion philosophy is shown in flow chart. 2 Referring to Fig. 4, the decision making unit (3) comprises of code generator sub-module (14) and generated code sub-module or Real Time Decision Display Unit (15). Referring to flow chart (3), the code generator sub-module (14) uses Data Dictionary, Rule Base and parameter file and two system files, i.e. automation file and relational operator file for generating the output code. The Code Generating submodule functions are shown in fig. 5 data Dictionary defines all the variable names with their initial values and subroutine names used in the Rule Base. The data in Data Dictionary is logically classified into following five categories: (i) variable data (all sensor related data) (ii) fixed data (remains fixed during operation) (iii) working variable (computed in real time) (iv) message variable (for displaying messages) (v) Logical variable (sent to TRUE OR FALSE depending on condition and reset to FALSE at every instant of time). Parameter data file contains the fixed value parameters, i.e. maximum length of a rule, mission identification, number of tracking sensors (being used by the decision making unit (3)), sensor identification which are used by the system. The acquisition of knowledge and updating the rule base being a continuous process, special care has been taken to check the syntax of the rules by using Automation File and Relational Operator file. After reading a rule, each character of the rule is checked with the states of automation and thus syntax of rules is checked. The syntax of the Rule Base is analysed and verified character by character by an automation whose state transition information is stored in the automation file. If all the rules are valid the final output code is generated. The Generated Code (15) is used in real-time to access sensor/health data, process the Rule Base and display real time decision. Before using for real time, all the data files are updated using relevant flight related data and the output code is generated by running the Code Generator module. Flow chart.3 shows the Generated Code Sub-module or Real Time Decision Display Sub-module (15). After getting all three fused sensor data and health data from Multi-Sensor-Data-Fusion module (9). Decision Display Sub-module (15) computes different flight safety parameters (e.g. critical angle margin, Instantaneous Impact Point margin etc.) for each of the three channels and then processes the rule Base. The Decision Display Sub-module (15) consists of Sensor-data-sub-module (16), Trajectory Sub-module (17), Nominal trajectory sub-module (18), Critical agnle sub-module (19), Instantaneous Impact Point sub-module (20), Rule Base sub-module (21) and Graphic Display sub-module (22) as shown in Fig. 6. Referring to Fig. 5 sensor-data sub-module (16) acquires data either from the Multi-sensor data fusion module (9) from remote computer or from local data files. It supplies data to trajectory sub-module (17), which computes current flight trajectory parameters based on the data received from module 16. The nominal trajectory sub-module (18) computes the nominal trajectory parameters based on a pre-stored nominal trajectory data base. Critical angle sub-module (19) computes the critical angle parameter based on computation results of module 17 and pre-stored critical angle tables. Instantaneous impact pint sub-module (20) computes instantaneous impact point based on the computation results of sub-module 17 and from pre-stored tables of limit lines it computes the angular margin by which the flight object escapes beyond the limit lines. The Rule base sub-module (21) utilizes parameters computed by all the modules (17, 18, 19, 20) to reach a decision. All the above mentioned modules compute one set of parameters for each of the three channels of data obtained from fusion module (9). Flow chart. (4) & (5) illustrate the decision making process in the Decision Tree. The Rule Base selects the sensor based on majority voting, i.e. incase all the fused data (ground and onboard) agree- it is fused further for inference engine feed back and optimum decision is made based on knowledge bank. In case of non agreement of fused sensor trajectory data, health parameters data are processed using knowledge base for input to inference engine for decision. Fig.8 shows the graphic Display of decision sub-module (22). This provides output in the form of interactive graphic display output as well as audio alarm of the real time flight safety decision. This displays the main Flight Safety Decision together with the reasoning behind the Decision. The main Display window has five sub-windows as shown in Fig. 8. The main decision window (25) displays the most vital information, i.e. decision reached by the decision display unit (15) after processing and analyzing the sensor data. It displays the flight safety decision in the form of 'NORMAL FLIGHT' /ALERT'/ TERMINATE FLIGHT'. Critical Flight safety parameters window (23) displays two critical parameters involved in decision-making, i.e. critical angle margin and impact point margin. Vehicle stage vectors window (27) displays the flight time, down range, altitude, velocity, identity of selected sensor etc. The health window (26) displays the critical health parameters, e.g. propulsion (normal/abnormal), thrust cut time, body rates, status of occurrence of critical events etc. The Miscellaneous window (24) displays the identity of the flight object, date, flight phase, sensor track status. It also contains the display representing the activity of a watchdog timer. The entire display is update at 1 sec interval. Different levels of emergencies are intimated by different colour codes (e.g. green-normal, yellow-alert, red-terminate etc) as well as persistent audio alarm. The real time flight monitoring system of the present invention is capable of operating into real time mode as well as offline simulation mode. In the real time mode, the data is taken from different sensors over the network using UDP/IP protocol in real time during the flight for providing decision aid to Range safety Officer. The system can also be used for training of the personnel, validate the system readiness as well as post flight analysis. In this mode, the data is read from the stored data files. The present embodiment of the invention, which has been set forth above, was for the purpose of illustration and is not intended to limit the scope of the invention. It is to be understood that various changes, adaptations and modifications can be made in the invention described above by those skilled in the art without departing from the scope of the invention which has been defined by following claims. WE CLAIM: 1. A real time flight monitoring system for monitoring of air-borne vehicles in real time and comprising: a trajectory data acquisition unit (1) for receiving data from ground based sensors like radar, electro-optic tracing instruments as well as for receiving data from sensors mounted on the said air-borne vehicles section inertial navigation system and processing the said data; a data processing, filtering and fusion unit (2) coupled with the said trajectory data acquisition unit (1) for receiving the said processed data from the said trajectory, data acquisition unit (1) and further processing and fusing the said processed data using Kolman filter fusion algorithm; a decision making unit (3) coupled with the said data processing, filtering and fusion unit (2) for further receiving the said fused data from the said data processing, filtering and fusion unit (2) and computing the different flight safety parameters and processing the rule base in providing filght safety decision; a decision output display unit (4) coupled with the said decision making unit (3) and providing the interactive graphic display and audio as output of the said real time flight monitoring system; a simulation/post flight unit )(5) compiled with the said decision output display unit (4) for performing post flight analysis. 2. A real time flight monitoring system as claimed in claim (1), wherein the said trajectory date acquisition system (1) comprises a cascaded arrangement of data acquisition unit (6) coupled to angular data trajectory extraction unit (7), said extraction unit (7) couplied to dagta validation unit (8). 3. A real time flight monitoring system as claimed in claim (1), wherein the said data processing, filtering and fusion unit (2) comrpises a kalman dynamic filter (10) a multi sensor fusion module (9) and at least three trajectory fusion sub modules (11), (12) and (13). 4. A real time flight monitoring system as claimed in claims 1 to 3 wherein said fusion module (11) provides fusion for first trajectory estimation by track and track extraction from the priority logic and send the fused data to the said decision support. 5. A real time flight monitoring system as claimed in claims 1 to 3, wherein the said fusion module (12) provides fusion for second trajectory extraction for ground based sensors and send the fused signals to the said decision support system. A real time flight monitoring system as claimed in claim (1), wherein said fusion module (13) provides fusion for third trajectory extraction for sensors like inertial navigation system and global positioning system mounted on the said air borne vehicle and sends the fused data to the said decision support system. A real time flight monitoring system as claimed in claim (1), wherein the said decision making unit (3) comprises a cascaded arrangement of a code generator sub module (14) and a decision display sub module (15). A real time flight monitoring system as claimed in claim (1), substantially as described and illustrated herein.

Documents:

1170-del-2002-abstract.pdf

1170-DEL-2002-Claims-(27-03-2009).pdf

1170-del-2002-claims.pdf

1170-del-2002-complete specification (granted).pdf

1170-DEL-2002-Correspondence-Others-(16-12-2008).pdf

1170-DEL-2002-Correspondence-Others-25-02-2008.pdf

1170-del-2002-correspondence-others.pdf

1170-del-2002-correspondence-po.pdf

1170-DEL-2002-Description (Complete)-(16-12-2008).pdf

1170-del-2002-description (complete).pdf

1170-DEL-2002-Drawings-(16-12-2008).pdf

1170-DEL-2002-Drawings-25-02-2008.pdf

1170-del-2002-drawings.pdf

1170-DEL-2002-Form-1-(16-12-2008).pdf

1170-del-2002-form-1.pdf

1170-del-2002-form-18.pdf

1170-DEL-2002-Form-2-(16-12-2008).pdf

1170-DEL-2002-Form-2-25-02-2008.pdf

1170-del-2002-form-2.pdf

1170-DEL-2002-Form-3-25-02-2008.pdf

1170-del-2002-form-3.pdf

1170-DEL-2002-GPA-(16-12-2008).pdf

1170-DEL-2002-GPA-25-02-2008.pdf