Research On The Compliance Control Of The Rotational Orthosis For Walking With Arm Swing

Stroke and spinal cord injury often cause limbs movement disorder.Patients are very eager to recover the movement abilities,however,they do not have access to the rehabilitation training in time because of the limited rehabilitation medical resources.Functional impairment can affect the quality of family life.As a product of the development of science and technology,rehabilitation robotics can help the patients regain the movement abilities and relieve the strained rehabilitation medical resources.Thus,our lab developed an Improved Rational Orthosis for Walking with Arm Swing,which was named ROWAS II.The ROWAS II system was designed based on the theories of brain plasticity and interlimb neural coupling of upper and lower limbs.This thesis developed passive and active control algorithms on the ROWAS II system to meet the rehabilitation needs for the patients.Besides,some able-bodied participants were recruited to test the control algorithms of the ROWAS II system.The ROWAS II system has the potential to promote the development of rehabilitation robotics in China.Firstly,this thesis briefly introduced the whole mechanical structure of the ROWAS II system.According to the rehabilitation needs,this thesis developed the overall control scheme for the ROWAS II system and determined the control strategies to realize passive and active training for upper and lower limbs.Besides,the method of error analysis was used to evaluate the control strategies of the ROWAS II system.Next,the closed-loop position control algorithms were developed in the upper limb rehabilitation device of the ROWAS II,which were based on the pole-placement approach.This approach allows the participants to perform passive movement.The compliance control strategies were developed on the tested platform for arm rehabilitation,where the closed-loop force controller,impedance controller and friction compensation model were developed,respectively.The able-bodied participants evaluated these control strategies.Then,the passive and active control systems were developed in the lower limb device of the ROWAS II system.According to the design method of the passive controller for the upper limb,the closed-loop position controllers were implemented in the bilateral hip,knee and ankle joints,respectively.The robustness of the passive control system was assessed by the experiments.By means of the force sensors installed at the end of the bilateral devices of the knee and ankle joints,admittance control algorithms were developed so that the lower limb has the compliance.Besides,the adjustable admittance control strategy was deduced and applied on the right ankle joint.In this experiment,the four cases tested the response of the ankle mechanism to active ankle dorsiflexion and plantarflexion.The passive and active control systems were tested and evaluated by the able-bodied participants.Finally,this thesis developed a linkage control system of the upper and lower limbs based on the passive and active control strategies.The participants achieved the walking-like movement in the bilateral upper and lower limbs in the linkage control system.The results can provide basis for furture researching on the interlimb neural coupling of upper and lower limbs.Based on the admittance control in the ankle mechanism,this thesis developed the ROM-adaptive control system,where the voluntary movement abilities of the right ankle joint can adjust the range of the bilateral shoulder,hip,knee and ankle joints.These control systems improve the overall control strategies of the ROWAS II system.In summary,this work briefly introduced the mechanical structure and overall control system of the ROWAS II system,and the simplified tested platform for arms training was designed to perform research on the compliance control algorithms.The passive control system of the upper and lower limbs and the active control system of lower limb were implemented in the ROWAS II system.What's more,the active control system of upper limb was developed in the tested platform.The able-bodied participants evaluated all control systems.The results of these experiments demonstrated each control system was stable and executable.The ROWAS II system has potential to clinical testing.