Functional electro stimulation closed loop fuzzy proportional integral derivative (PID) control method

Abstract

The invention discloses a functional electro stimulation closed loop fuzzy proportional integral derivative (PID) control method, which includes obtaining an expression of torque of the knee joint; establishing a muscle model; adjusting stimulation current through a fuzzy PID controller, and obtaining a practically output torque value of the knee joint through the muscle model; obtaining errors and error change rate; inputting the errors, the error change rate and the stimulation current into a fuzzy inference system which processes the errors, the error change rate and the stimulation current and converts the errors, the error change rate and the stimulation current into corresponding fuzzy quantity; obtaining control rules, and setting three parameters of the PID controller according to the control rules; adjusting the stimulation current according to parameters after setting, and obtaining newly and practically output torque value of the knee joint through the muscle model; and finishing the process until an error between the newly and practically output torque value of the knee joint and an expected torque value of the knee joint is smaller than a threshold value. The functional electro stimulation closed loop fuzzy PID control method can effectively improve stability and accuracy of the functional electrical stimulator and obtain considerable social benefits and economic benefits.

Description

technical field [0001] The invention relates to the technical field of devices that use electrical pulse stimulation to help disabled people recover, and in particular to a functional electrical stimulation closed-loop fuzzy PID control method. Background technique [0002] FES (Functional Electrical Stimulation, Functional Electrical Stimulation) is a technology that stimulates limb motor muscles and peripheral nerves through current pulse sequences to effectively restore or reconstruct part of the motor function of paraplegic patients. According to the treatment statistics for paralyzed patients with spinal cord injury, due to the weak regeneration ability of the spinal cord, there is no effective treatment method that can directly repair the injury, and functional rehabilitation training is an effective measure. The number of paralyzed patients with spinal cord injury is increasing year by year, and functional rehabilitation training is an urgently needed technology. In ...

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Problems solved by technology

[0005] 1. The current research on FES trigger control methods mainly relies on a series of manually operated switches and some external sensors, and the obtained results of current stimulation intensity are not accurate and stable;

[0006] 2. In order to achieve a better control effect in PID control, the three control functions of proportional, integral and differential must be adjusted to form a relationship of mutual cooperation and mutual restriction in the control quantity. There is no good adjustment method in the prior art

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