Reconfiguration method for a sensor system comprising at least one set of observers for failure compensation and guaranteeing measured value quality

• US 6,999,906 B2
• Filed: 07/18/2002
• Issued: 02/14/2006
• Est. Priority Date: 07/20/2001
• Status: Active Grant

• Current Assignee: Airbus Defence and Space GmbH
• Original Assignee: EADS Deutschland GmbH (Airbus SE)
• Inventors: Lohmiller, Winfried, Koehler, Thomas
• Primary Examiner(s): Bui, Bryan
• Assistant Examiner(s): LE, JOHN H
• Application Number:
  US10/484,046
• Publication Number:
  US 20040216000A1
• Time in Patent Office: 1,307 Days
• Field of Search: 702/65, 702/79, 702/128, 702/185, 702/186, 702/190, 702193-195, 621/26, 236/35, 714/4, 701/29
• US Class Current: 702/193
• CPC Class Codes: G05B 23/0254 based on a quantitative model, e.g. mathematical relationships between inputs and outputs; functions: observer, Kalman filter, residual calculation, Neural Networks
• CPC Class Codes: G05B 9/03 with multiple-channel loop, i.e. redundant control systems

Abstract

The invention relates to a reconfiguration method designed to be implemented in a computer system, for compensating failures of a sensor system (1). The sensor system includes at least one sensor (2, 50) for measuring (12, 22) system states of an application system (11, 21) and at least one system model (4) for describing the application system, which together form at least one first observer (6) for estimating system states in order to provide system states for an allocated data processing device (14, 24). According to the method, failure states for a first observer are determined from deviations, which occur as a result of the comparison between a number of states measured by the sensor or sensors and a state estimated by the system model.

Claims

1. A reconfiguration method for implementation in a computer system for compensating failures of a sensor system (1) with at least two observers, each observer being formed by at least one sensor (2, 50) for measuring (12, 22) system states of an application system (11, 21) and by at least one system model (4) for estimating of system states of the application system, in order to make system states with a predetermined reliability available to an allocated data processing unit (14, 24), said method comprising the following steps:

(a) ascertaining failure states based on time related deviation values for a first observer by comparing of a number of states measured by said at least one sensor, with a state estimated by said at least one system model,

(b) initiating at least one further observer in response to the reaching of a first threshold level of said deviations, said further observer having a number of past time steps for determining a failure status of the further observer, and

(c) transmitting the system states ascertained by the further observer to the data processing unit (14, 24) for further processing, as soon as the first observer has reached a second threshold value.

2. The reconfiguration method of claim 1, wherein, in response to the first observer exceeding the first threshold value, that further observer is selected which has the smallest deviations of the system states over a predetermined past time interval.

3. The reconfiguration method of claim 1, further comprising selecting a further observer in accordance with a predetermined sequence, when the first observer exceeds the first threshold value.

4. The reconfiguration method of claim 1, wherein the first combination is initiated by the further combination and sending system states for further processing to the data processing unit (14, 24) as soon as the first combination falls below the first threshold value.

5. The reconfiguration method of claim 1, comprising ascertaining the deviations by means of a confidence estimate.

6. The reconfiguration method of claim 5, comprising performing the confidence estimate by means of a Gauss-method or a quadrilateral method.

7. A sensor system for the determination of external states of an application system (11), said sensor system comprising an allocated data processing unit (14) for receiving said external states, at least two observers (6) with at least one respective sensor (2) and at least one respective system model representing the application system (11), said sensor system being adapted for performing functions in accordance with the method steps (a), (b) and (c) as defined in claim 1.

8. The sensor system of claim 7, wherein said application system is a vehicle.

9. The sensor system of claim 8, wherein a position or an attitude of the vehicle in space is used as an external state.

10. The sensor system of claim 7, wherein said sensor system is an air data system.

11. The sensor system of claim 7, wherein said data processing unit (14) is a monitor.

12. A sensor system for the determination of operational states of an application system (21), said sensor system comprising an allocated data processing unit (24) for receiving said operational states, and at least one set of observers (6) with at least one sensor (2) and a system model representing the application system (11), said sensor system being adapted for performing functions in accordance with the method steps of claim 1.

13. The sensor system of claim 12, wherein the application system is a control system and wherein the operational states are a position and/or a speed of a servo-valve or of an actuator.

14. The sensor system of claim 12, wherein the application system is a control system and wherein the operational states are pressures.

15. The sensor system of claim 12, wherein the application system is a chemical system and the operational states are a reaction temperature, a concentration of materials reacting with each other, or pressures.

16. The sensor system of claim 12, wherein the application system is an electrical system and the operational states are currents, voltages, capacities or material characteristics.

17. The sensor system of claim 12, wherein said data processing unit (24) is a monitor.