Force moment zero-searching method for elastic drive joint

Abstract

The invention discloses a force moment zero-searching method for an elastic drive joint. The method comprises the following steps of: systemically electrifying the elastic drive joint, and starting a motor; positively or negatively rotating the motor at low speed, and stopping rotation of the motor when current of the motor is greater than a current threshold value; obtaining feature motor current when the motor reaches a feature point, a feature relative motor rotation angle measured by an incremental coder and a feature joint angle measured by an absolute type position sensor in a rotation process of the motor; and determining a relative angle between an electrifying reference zero point and an absolute zero point on the incremental coder according to the feature motor current, the feature relative motor rotation angle, the feature joint angle as well as a pre-determined first feature relative angle when the motor reaches a feature point and an absolute zero point at the first time after starting. The force moment zero-searching method disclosed by the invention realizes zero-searching of the incremental coder, so that the incremental coder can be used for measuring deformation amount of an elastomer; and moreover, an SEA joint structure is simplified, and the production cost is reduced.

Description

technical field [0001] Embodiments of the present invention relate to joint drive technology, and in particular to a torque zeroing method for elastic drive joints. Background technique [0002] Joint bionic drive technology has become an important research direction in the field of robotics, and as a force output drive device with flexible drive and bionic drive capabilities, Series Elastic Actuator (SEA) is widely used in the field of robotics. [0003] When the SEA joint needs to have torque feedback and double closed-loop arrangement at the same time, three position sensors are generally required: an incremental encoder is used to measure the motor speed, and two absolute position sensors are used to measure the joint rotation angle and elastic body deformation respectively. [0004] In some cases, an absolute position sensor can be used instead of an incremental encoder, thereby eliminating the need for an incremental encoder, so that only two absolute position sensors ...

AI Technical Summary

Problems solved by technology

However, when the motor speed is high, the absolute position sensor cannot meet the high speed requirements because the maximum rotational speed of the absolute position sensor is relatively small

Moreover, the price of absolute position sensors is higher than that of incremental encoders, which also increases production costs.

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