Method for measuring joint torque through optical-electricity encoder and joint control method

Abstract

The invention relates to a method for measuring the joint torque through an optical-electricity encoder. By the adoption of the method, the joint torque can be measured more simply and accurately. The method comprises the steps that S1, an angle value signal of the angle position change of a flexible wheel shaft relative to a joint output shaft in the motion process of a motor is collected by a signal collecting circuit of the optical-electricity encoder in real time; and S2, the angle value signal collected in the step S1 is received through a joint controller and subjected to calculation processing. The step S2 specifically comprises the substeps that S21, the torque T of each linear spring in an elastic unit is obtained through calculation; and S22, the torque of the joint output shaft is obtained by superimposing the torques T of all the linear springs in the elastic unit. The invention further relates to a control method of a robot joint, the obtained torque value is compared with a torque reference value and a joint torque compensation value, a torque difference value is obtained, then the torque difference value is converted into a motor control signal through a torque current loop control module, and finally operation of the motor is controlled, so that simpler and more accurate control over the joint is achieved.

Description

technical field [0001] The invention relates to a method for detecting joint torque, especially a method for measuring joint torque by using a photoelectric encoder, which is mainly used in robot joints. The invention also relates to a control method for robot joints based on the measurement method. Background technique [0002] At present, torque sensors are generally used to measure the torque of robot joints, including non-contact torque sensors and strain gauge torque sensors. [0003] Among them, the input shaft and output shaft of the non-contact torque sensor are connected by a torsion bar, and the splines on the input shaft correspond to the key grooves on the output shaft. When the torsion bar is twisted by the turning torque of the steering wheel, the relative position between the spline on the input shaft and the keyway on the output shaft is changed. The amount of relative displacement change between the spline and the keyway is equal to the twisting amount of t...

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Problems solved by technology

[0008] In this regard, the application publication number is CN 104198098A's invention patent application "torque measurement sensor and measurement method based on photoelectric code disc signal phase difference" to propose a solution, but, because it needs to install two photoelectric encoders and elastic link, which makes it have complex structure, redundant torque acquisition methods and other deficiencies

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