Research On Algorithm For Multiplying The Frequency Of The Sensor Signal And Control System For The Parallel Mechanism On Hip Joint

In recent years, the research on the Wearable Power Assist Robot become more popular, which involves a lot of disciplines, such as human anatomy, ergonomics, biomechanics, robotics, mechanism, artificial intelligence and information fusion. The Wearable Power Assist Robot is a typical exoskeleton, which can expand human's motion capacities. The robot can drive itself according to motion information of the human obtained by the sensor system, so that it can provide power to assist human's motion.Whether the information about the human's motion obtained by the sensor system is timely and accurate or not may affect the effect of the power assist robot. In order to improve the delay and the lower response frequency of the sensor signal, we present an algorithm to multiply the sensor signal's response frequency based on real-time predicting. This algorithm has the advantages about the predictability and sleek compensatory. Therefore, it not only can gain the human's motion information earlier, but also can increase the sensor signal's frequency many times.Because of the lack of the serial mechanism's mechanical properties and the physiological characteristics of the human hip joint, we decide to use parallel mechanism to design Power Assist Robot for human hip joint, and design the control system for it. Based on analyzing the kinematics of the parallel mechanism on only one degree of freedom what is in the direction of flexion and extension, we propose a method of decision of the control system based on the virtual compliance control method and the inverse Jacobian matrix on only one degree of freedom, which is the basis for the further research on Parallel Mechanism for power assist.This paper's main contents are as follows:1. From the view of the signal, we find an algorithm for real-time predicting based on the Moving Windows Quadratic Autoregressive (MWQAR) model and the improvement of the error. The algorithm contains the method of modeling the signal by the MWQAR model and estimating its parameters, and the method of using forecasted error to improve the effect of the predicting algorithm. The results of the experiments show that the algorithm can advance gaining the information of the human motion.2. Based on the real-time predicting algorithm, we propose a method to multiply the sensor signal's response frequency. The method is composed by the real-time predicting algorithm and the cubic spline interpolation method. Through the results of using the multiplying algorithm on the sensor signal, we can find that the algorithm is feasible and effective.3. We design a control system for the Power Assist Robot for the hip joint based on the parallel mechanism. While analyzing the virtual compliance control strategy based on interaction force and its adaptive adjustment, we analysis the kinematics of the parallel mechanism on only one degree of freedom, and find its Jacobian matrix between the speed of the mechanism's active joint and the speed of the hip joint in this direction. Based on the virtual compliance control strategy and the Jacobian matrix, we design the decision system of the Power Assist Robot's control system. By applying the software of the control system based on the decision system, we finish the experiments of controlling the Power Assist Robot to help the hip joint to move in flexion and extension.