Intelligent Artificial Leg Controller Algorithms Design And Walking Speed Measure Module Develop

Intelligent electromechanical artificial leg is a complex nonlinear control system mainly comprising knee joint, actuator, ankle joint, foot as well as intelligent controller etc. This project integrates intelligent control theory, microelectronic technology, computer control technology, mechanical design and manufacture technology, biomedical engineering with rehabilitation medicine engineering etc. Its crucial part is intelligent controller, which controls bend and stretch of the knee joint of artificial leg as well as shank swing and often adopts fuzzy control strategy. The develop of intelligent artificial leg have significant social meaning and the role of decision for handicapped person's returning society and improving the quality of life.This paper has synthesized and analysed the present situation and the history of research work of domestic and international artificial leg, and points out the problem of existing artificial leg controller on this foundation, and advances the improvement scheme. In the part of algorithm design of intelligent artificial leg controller, this paper has first introduced the basic content of genetic algorithm and fuzzy control. From the analyse of influence of operator parameters on the response of Fuzzy control system, it is educed that the excellent performance of dynamic and steady cannot be obtained when applying the fixed parameters Fuzzy controller. Then there is need that parameters should be online autoregulative according to the system control process. Aiming at the defect of the fixed parameters Fuzzy controller, This paper designs a formulae of self-tuning operational parameters and proposes a fuzzy controller whose operational parameters can automatically adjust according to the system's current dynamic error based on genetic algorithms optimization. The result of computer simulation shows that it is more excellent than the fuzzy controller whose parameters are fixed in dynamic behavior and steady-state performances of system response. It has very strong applicability and can be utilized extensively in controlling various objects. It is very significant to enhance the performances of intelligent controller and realize real time, fast and accurate control so as to improve the walk performances of artificial leg.The excellent feature of intelligent artificial leg is that the speed of bend and stretch of its knee joint can change with the change of amputee's walking speed, so the measurement module of walking speed is an important unit. This paper proposes a method of walking speed measure, which is sampling continuously the value of speedmeasurement and calculating the average in the time-interval intended. Then the rate corresponding to the average is used as the given value of controller. A new kind of advanced sensor, i.e.ENV-05F angular velocity sensor is adopted in the circuit for the first time. This kind of sensor can instantaneously catch the angular velocity of swing of thigh. This sensor is very suitable installed in the artificial leg due to its small volume, lightweight, responding quickly. Using this sensor as walking speed sampling sensor, this paper develops the measurement module of walking speed based on AT89C51 singlechip. Experimentation shows that this module circuit can effectively respond to the walking speed of healthy side leg and immediately offer intelligent controller given value through the interface circuit with controller of artificial leg.