A motion control method for a soft actuator

Abstract

The invention belongs to the technical field of hand rehabilitation and flexible robot control, and discloses a motion control method of a flexible actuator. The method comprises the following steps that (1) a step response test is conducted on the flexible actuator so as to obtain a time domain equation under input of all step response signals through fitting, and then fitting is conducted on theobtained time domain equation to obtain a second-order system time domain equation; (2) the second-order system time domain equation is converted into a differential equation; (3) after a high-orderpolynomial input of the step response signals in the differential equation is simplified into a primary polynomial, the simplified equation is converted into a dynamic equation of the flexible actuator; and (4) a sliding mode function and a Lyapunov function related to the flexible actuator are constructed, calculating is further conducted to obtain the control rate of the flexible actuator when the derivative of the Lyapunov function is smaller than or equal to zero, thereby the flexible actuator is controlled according to the control rate. According to the method, the control precision is improved, and the flexibility is good.

Description

technical field [0001] The invention belongs to the related technical field of hand rehabilitation and soft robot control, and more specifically relates to a motion control method of a soft robot. Background technique [0002] Nowadays, the aging of the social population is getting worse, and the number of people with hemiplegia caused by stroke and other diseases is increasing. At the same time, the number of people with impaired hand motor function due to accidents such as production accidents and traffic accidents is also increasing year by year. These patients are often unable to take care of themselves due to limb motor dysfunction, which brings a lot of pressure to the family and society. Robot-assisted rehabilitation training can save a lot of manpower and material resources, and can quantitatively evaluate the rehabilitation of patients, and carry out training step by step according to the rehabilitation status of patients. [0003] In hand rehabilitation training, ...

AI Technical Summary

Problems solved by technology

[0004] Although soft actuators with flexible structures have very good application prospects in hand motor rehabilitation, the research on soft actuators is not mature, which shows that there is no suitable sensor that can better control the bending angle of soft sensors. Measurement

Although thin-film flexible bending sensors on the market can measure bending, they cannot be well integrated into soft actuators due to the serious influence of surface pressure on the measurement

In addition, since the soft actuator is driven by pneumatics, the high hysteresis of the pneumatic and the weak stiffness of the soft structure will make the control very difficult to ensure its accuracy, which usually leads to trembling

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