Intelligent Controller Based On DSP And Its Application To Intelligent Artificial Legs

Intelligent artificial leg has been an interesting research project in the fields of robotics and biomedical engineering, its most excellent characteristics is that it can imitate the movement ways of human healthy legs and its walking speed can change naturally with the change of amputee's walking speed. The research on this project is of practical significance to improving the living situation and welfare benefits of amputees.Intelligent artificial leg swing to rely on flexible realization of pneumatics cylinder. The motor of pneumatics cylinder tail can control the open degree of a needle in cylinder (flow control valve) .Through changing the open degree of valve, knee joint bend and extend damping is changed and get the speed we needed. Intelligent artificail legs developed before have shortages in twe aspects.On the one hand, its controller,which is used to control the open degree of needle of pneumatics cylinder in these legs, is an open-loop system composed of a stepping motor,and has low position precision. On the other hand, it's CPU much adopting is the singlechip machine of 51 serieses, which running speed can not satisfy the needs of advanced algorithm. Aim at the twe shortages,we make following improving scheme:(l).Using servo DC to replace stepping motor, make it realize accurate location control in big scope.(2).Have designed a closed-loop control system with location and current feedback and carry out optimization with GA for PID parameter, at the same time, lead into fuzzy control theory to make PID parameter to be decided on-line.The improvement of control strategy raises the respondspeed and accuracy of gait adjustment of intelligent artificial leg.(3).The CPU of intelligent controller adopts the DSP chip TMS320F240PQ of TI company' production.The IC is designed for motor control and its integrated degree is high and its running speed is tens times of that of singlechip machine of 51 series and has powerful instructin set.It is easy to complete the on-line operation of advanced algorithm.Pass through produce and the design of controller hardware, software compile, debug as well as test , the results indicate that the intelligent artificial leg'intelligent controller proposed here raises the intelligent behavior, robustness, response speed and accuracy of the control system.