| This paper aims to establish a high-performance deep-sea robotic joint brushless DC motor drive system.Firstly,the deep-sea environment factors should be combined to determine the system structure.Afterwards,the information fusion method is used to improve the detection capability of the system position sensor.In order to ensure the reliable operation of the system and the correct use of the position sensor information fusion method,the fault diagnosis of the Hall position sensor is studied.Finally,the bus current harmonic suppression method of the pressure-supported motor drive system is studied.Establishing brushless DC motor(BLDC)drive system for deep-sea robot manipulator.Combined with the structural characteristics of the drive system and detection features of the position sensors.Undertaking research into the information fusion method between the Hall position sensor and the resolver.This part of research,which is based on sensor fusion technology includes the reliable estimation method for the rotor position of the BLDC and the method to improve the positioning accuracy of the drive system.The Hall position sensor’s trouble-free operation is a necessary condition for position sensors fusion,which is also an essential condition for the operation of the motor drive system.Therefore,fault diagnosis and fault-tolerant control of Hall position sensor are reseached in this part.Reseach includes analyzing the edge signal of the Hall position sensor,which implies information on motor state,proposing the fault diagnosis method based on the edge detection of the Hall signal.Dc-bus capacitance is an indispensable part of the motor drive system.Considering environmental factors of the deep sea,choosing the film capacitor as the dc-bus capacitor of the motor drive system.However,due to the lower specific capacitance of the film capacitor and the limited volume of the drive system,it is difficult for the capacitance of the dc-bus capacitance to eliminate the effect of current ripple,which reduces the operating performance of the drive system.This part mainly reseaches on the dc-bus current ripple suppression method with small dc-bus capacitance.The reseach includes analyzing the current ripple source,calculating the optimal capacitance value for absorbing the PWM current harmonics,comparing commutation current between the traditional commutation strategy and the 12-step commutation strategy.Finally,determining the current ripple suppression method,which is applicable to motor drive system.Based on the principle analysis and simulation verification,the design of deep-sea robotic joint motor drive system and the construction of an experimental platform were completed.The experiment results verified that basic functions of the drive system and the feasibility of the above methods. |
