Harmonic drive type high-accuracy position control system and method

Abstract

The invention relates to a harmonic drive type high-accuracy position control system and method. For the nonlinear dead zone characteristic caused by harmonic drive flexibility, the system and method of the invention adopt a control structure in which a current loop sleeves a dual velocity loop and then sleeves a position loop, so the dead zone characteristic in system tracking control can be restrained, and the tracking control accuracy can be improved. The control method mainly utilizes the advantage that multiple closed-loops exist in the output feedback, the current loop is adopted to increase the stationarity of the output force moment, the position measured by a rotary encoder is utilized to decouple the rotating speed of the motor rotor to form a speed closed-loop of the motor end, the nonlinear characteristics, such as the flexibility, the friction, etc., of a harmonic reducer are isolated in advance, and the motor anti-interference capability can be enhanced. Then, accurate control is performed on the load by combining with the outer speed loop formed by a speed measuring device and a photoelectric encoder and the position loop at the load end. Compared with the existing harmonic drive type high-accuracy control technologies, advantages of high accuracy, simple control structure and convenient debugging can be realized.

Description

technical field [0001] The invention belongs to the field of high-precision servo control of harmonic drives, and in particular relates to a high-precision control system and method of a harmonic reducer in a photoelectric tracking system. The harmonic reducer belongs to the flexible gear transmission, so the platform with the harmonic reducer will inevitably be affected by the nonlinearity brought by the transmission gap and flexibility, which is mainly manifested as a dead zone phenomenon. The invention helps to suppress the non-linear characteristics of the dead zone caused by gaps and flexibility, and improves the tracking accuracy of the servo system. technical background [0002] Harmonic transmission is a transmission technology developed rapidly in the 1980s and 1990s. It stands out among various reducer transmissions with its advantages of small size, light weight, large transmission ratio and small transmission gap. It uses the difference in the number of teeth be...

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Problems solved by technology

For example, in the article "Research on Harmonic Drive System Based on Acceleration Sensor Feedback Control" by Qiu Zhicheng and others ("China Mechanical Engineering", 2000, Vol. 11, No. 11, pp. 1201-1205), in order to suppress the flexibility, Due to the vibration caused by nonlinear friction and other factors to the load, a feedback control based on the acceleration sensor is proposed, which increases the active damping of the system to suppress the nonlinear disturbance of the system, but this method needs to introduce an accelerometer to measure the acceleration of the load

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