Limits...
Fault diagnostics for turbo-shaft engine sensors based on a simplified on-board model.

Lu F, Huang J, Xing Y - Sensors (Basel) (2012)

Bottom Line: The simplified on-board model provides the analytical third channel against which the dual channel measurements are compared, while the hardware redundancy will increase the structure complexity and weight.Sensor fault detection, diagnosis (FDD) logic is designed, and two types of sensor failures, such as the step faults and the drift faults, are simulated.When the discrepancy among the triplex channels exceeds a tolerance level, the fault diagnosis logic determines the cause of the difference.

View Article: PubMed Central - PubMed

Affiliation: College of Energy and Power Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China. lfaann@nuaa.edu.cn

ABSTRACT
Combining a simplified on-board turbo-shaft model with sensor fault diagnostic logic, a model-based sensor fault diagnosis method is proposed. The existing fault diagnosis method for turbo-shaft engine key sensors is mainly based on a double redundancies technique, and this can't be satisfied in some occasions as lack of judgment. The simplified on-board model provides the analytical third channel against which the dual channel measurements are compared, while the hardware redundancy will increase the structure complexity and weight. The simplified turbo-shaft model contains the gas generator model and the power turbine model with loads, this is built up via dynamic parameters method. Sensor fault detection, diagnosis (FDD) logic is designed, and two types of sensor failures, such as the step faults and the drift faults, are simulated. When the discrepancy among the triplex channels exceeds a tolerance level, the fault diagnosis logic determines the cause of the difference. Through this approach, the sensor fault diagnosis system achieves the objectives of anomaly detection, sensor fault diagnosis and redundancy recovery. Finally, experiments on this method are carried out on a turbo-shaft engine, and two types of faults under different channel combinations are presented. The experimental results show that the proposed method for sensor fault diagnostics is efficient.

No MeSH data available.


Related in: MedlinePlus

One channel sensor ng step fault under the steady state of ng% = 85%. (a) Triplex channel outputs; (b) Step fault indication by SPSO-SVR; (c) Step fault indication by simplified model.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC3472873&req=5

f8-sensors-12-11061: One channel sensor ng step fault under the steady state of ng% = 85%. (a) Triplex channel outputs; (b) Step fault indication by SPSO-SVR; (c) Step fault indication by simplified model.

Mentions: Experiments on one channel with a step fault and a drift fault under the steady-state of ng% = 85% are carried out. The magnitude of 2% step fault was injected into channel A at 15s in Figure 8(a). The dual-channel residual r grows about 28.7, and the analytic residual rA about 21.2, bigger than their thresholds τDR and τAR at 15 s, as shown in Figure 8(c). However the analytic residual rB does not violate its threshold τBR. Therefore channel A fault can be determined by the logic, and the diagnostic root cause is consistent with the sensor fault set. The SPSO-SVR method for sensor fault diagnosis in [28] is used for comparison, and the input and output of SPSO-SVR estimator are [Wf(k−1), Wf(k)] and ng(k), respectively. The SPSO-SVR steady estimation error is more than the simplified model one, so does the analytic residual threshold. The dual-channel residual r′ grows about 28.7, the analytic residual decreases to 12 at 15 s, and the analytic residual keeps 17, as shown in Figure 8(b). There are no residuals exceed themselves' thresholds and no sensor faults are determined, but it is not consistent with the truth and the misdiagnosis is produced.


Fault diagnostics for turbo-shaft engine sensors based on a simplified on-board model.

Lu F, Huang J, Xing Y - Sensors (Basel) (2012)

One channel sensor ng step fault under the steady state of ng% = 85%. (a) Triplex channel outputs; (b) Step fault indication by SPSO-SVR; (c) Step fault indication by simplified model.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3472873&req=5

f8-sensors-12-11061: One channel sensor ng step fault under the steady state of ng% = 85%. (a) Triplex channel outputs; (b) Step fault indication by SPSO-SVR; (c) Step fault indication by simplified model.
Mentions: Experiments on one channel with a step fault and a drift fault under the steady-state of ng% = 85% are carried out. The magnitude of 2% step fault was injected into channel A at 15s in Figure 8(a). The dual-channel residual r grows about 28.7, and the analytic residual rA about 21.2, bigger than their thresholds τDR and τAR at 15 s, as shown in Figure 8(c). However the analytic residual rB does not violate its threshold τBR. Therefore channel A fault can be determined by the logic, and the diagnostic root cause is consistent with the sensor fault set. The SPSO-SVR method for sensor fault diagnosis in [28] is used for comparison, and the input and output of SPSO-SVR estimator are [Wf(k−1), Wf(k)] and ng(k), respectively. The SPSO-SVR steady estimation error is more than the simplified model one, so does the analytic residual threshold. The dual-channel residual r′ grows about 28.7, the analytic residual decreases to 12 at 15 s, and the analytic residual keeps 17, as shown in Figure 8(b). There are no residuals exceed themselves' thresholds and no sensor faults are determined, but it is not consistent with the truth and the misdiagnosis is produced.

Bottom Line: The simplified on-board model provides the analytical third channel against which the dual channel measurements are compared, while the hardware redundancy will increase the structure complexity and weight.Sensor fault detection, diagnosis (FDD) logic is designed, and two types of sensor failures, such as the step faults and the drift faults, are simulated.When the discrepancy among the triplex channels exceeds a tolerance level, the fault diagnosis logic determines the cause of the difference.

View Article: PubMed Central - PubMed

Affiliation: College of Energy and Power Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China. lfaann@nuaa.edu.cn

ABSTRACT
Combining a simplified on-board turbo-shaft model with sensor fault diagnostic logic, a model-based sensor fault diagnosis method is proposed. The existing fault diagnosis method for turbo-shaft engine key sensors is mainly based on a double redundancies technique, and this can't be satisfied in some occasions as lack of judgment. The simplified on-board model provides the analytical third channel against which the dual channel measurements are compared, while the hardware redundancy will increase the structure complexity and weight. The simplified turbo-shaft model contains the gas generator model and the power turbine model with loads, this is built up via dynamic parameters method. Sensor fault detection, diagnosis (FDD) logic is designed, and two types of sensor failures, such as the step faults and the drift faults, are simulated. When the discrepancy among the triplex channels exceeds a tolerance level, the fault diagnosis logic determines the cause of the difference. Through this approach, the sensor fault diagnosis system achieves the objectives of anomaly detection, sensor fault diagnosis and redundancy recovery. Finally, experiments on this method are carried out on a turbo-shaft engine, and two types of faults under different channel combinations are presented. The experimental results show that the proposed method for sensor fault diagnostics is efficient.

No MeSH data available.


Related in: MedlinePlus