Model Based Fault Diagnosis of the Clamp Force Control System of Continuously Variable Transmission

On-line diagnosis is one of the most important modules in the control software of Continuously Variable Transmission (CVT). With the development of a prototype CVT, fault diagnosis method of the clamp force control system was developed. Configuration and working mechanism of the clamp force control system was analyzed in detail, based on which mathematic model of the system was established using bond graph theory. Precision of the model was then tested by experiment, and the test results indicated that the model was precise enough for diagnosis use. Fault diagnosis algorithm of the clamp force control system was developed based on the model. Experiment indicated that the proposed diagnosis method of the clamp force control system was effective.