Research On Control Method Of ARM Rehabilitation Robot

Arm rehabilitation robot is a kind of bionic robot for arm hemiplegia patient,which is based on rehabilitation medicine foundation. It’s mainly used in medicalfield, to help those patients who are arm movement disorders or upper-limbhemiplegia with rehabilitation training effectively and safely. Patient needs to wear onthe arm rehabilitation, and to choose the passive movement, active movement, activewith damping mode according to their arm recovery situation, to complete the routinerehabilitation training independently.With the increasing number of upper-limb hemiplegia patients, and the shortageof rehabilitation therapists, arm rehabilitation robot has caused more and morepeople’s attention nowadays. However, it’s couldn’t achieve the desired effect ofrehabilitation training because most domestic arm rehabilitation robot products adoptpassive rehabilitation training currently and there is no increase reverse dampingforce in the latter part of the rehabilitation training. For the existing problems, the armrehabilitation robot adopt direct force control which can provide upper limb a certainpower, no power or resistance, to achieve passive movement, active movement, activewith damping mode. This paper work done as follows:a. This paper has built the kinematics and dynamics model of the armrehabilitation robot according to the robot mechanical structure.b. For the active movement, this paper carried on modeling, simulation andexperimental research on the traditional PD direct force control separately. Thesimulation results show that traditional PD direct force control can limit theforce/torque which is0.5N mand0.3N mbetween human and machine, andmake the system achieve a good results fast, smooth and accurate, and better dynamicperformance in both high speed and low speed.c. A settled of PD parameters cannot fully meet system’s static performance anddynamic performance. The operator trajectory reverses in a short time will lead to apeak force/torque between human and machine. For the shortage of traditional PDdirect force control, the traditional PD control is extended to expert PD control. Thesimulation results show that expert PD direct force control can reduce the peak force/torque between human and machine by74.1%on shoulder and73.7%on elbowwhen the operator trajectory reversed in a short time.d. The traditional PD control and expert PD control experiment on armrehabilitation robot experiment platform tests the force/torque between human andmachine. The dynamic experiment results show that the traditional PD control canreduce the force/torque between human and machine by58.7%on shoulder and65.9%on elbow compared to uncontrolled, and the expert PD control can reduce theforce/torque between human and machine by33.0%on shoulder and23.4%on elbowcompared to traditional PD control. The step experiment results show that the expertPD control can reduce the force/torque between human and machine by76.84%onshoulder and100%on elbow compared to traditional PD control in the steady state.It’s suggested that the expert PD control better than the traditional PD control. Itreduces the force/torque between human more effectively and get a faster transientperformance and less overshoot, such that human feels more comfortable.