| With the development of space technology, marine technology, nuclear technology and other related technologies, there is an urgent need for a kind of telerobot working in such dangerous and extreme environment. This kind of telerobot provide the information of the working spot to the operator and the operator can make the right operation and complete the task well. The telerobot can not only protect the operator's health and safety, but also expand the human's working scope in which human can not accomplish the task directly. It will greatly enhance the working efficiency and create huge economic and social benefits.This dissertation is supported by National Natural Science Foundation of China(No.50475011) and "Study on new type force sense bilateral servo control of teleoperation construction robotic system" supported by Excellence Youth Teacher State Program of Ministry of Education. Based on the analysis of the telerobotic systems with telepresence in home and abroad, this dissertation has analyzed the bilateral servo control strategies including: position-position control strategy, position-force control strategy, force-force control strategy and other strategies. In these control strategies, there are some problems such as the position of the slave manipulator can not follow the master manipulator well, and there is concussion in the force feedback when the slave touch the rigid object. Considering those problems, we do much research on a new type bilateral control strategy. In the strategy, the displacement of the slave manipulator is controlled by the force deviation of the master and slave manipulator, and the master manipulator which controlled by the position deviation between the master and slave moves following slave manipulator. The experiment shows that the telerobotic system with this kind of control strategy has a good ability in the position control of the master and slave manipulator, and it can well decrease the force concussion. We have set up a 4-DOF electro-hydraulic servo master-slave telerobotic system and design the controllers of master and slave manipulators. The teleoperation were done in different load conditions. Combined the research of theory and experiment, we have accomplished the main research tasks as follows:1. Built up the 4-DOF electro-hydraulic servo master-slave telerobotic system based on Internet on the foundation of the 2-DOF forceback manipulator system and 4-DOF electro-hydraulic construction telerobotic system in our labs, and the network comunications between the master and slave side was realized in the campus LAN. The characteristics of the network comunications were also analyzed and the problems of the data packet in network comunications such as loss, confussion and time-varing delay were solved. The experiment verified the feasibility.2. Set up the mathematical models of the master-slave electro-hydraulic systems. Deduced the transfer functions of the master and slave electro-hydraulic servo systems. Built up the mathematical models of the amplifiers, electro-hydraulic servo-valves, the liquid presses motors, and proportional valves, hydraulic cylinders in detail. Took Matlab/Sumilink as a tool, analyzes the open loop transfer function responds dynamic characteristics. Deleted a certain insignificant poles of the transfer functions to make the high-order transfer function to the low-order transfer functions. This provided referenced mathematical models for master-slave telerobotic system and the principle for designing controller.3. In order to get favorable dynamic and static characteristics for electro-hydraulic servo systems, we designed controllers for both master and slave of the 4-DOF electro-hydraulic servo system. In the telerobotic system, the surroundings may be complex and uncertain, and the stiffness of the objects may be different, the normal PID controller can not perform well in these cases. To solve this problem, this dissertation designed an adaptive fuzzy PID controller. This controller has a high control precision like PID controller and good flexibility like adaptive fuzzy controller. The result from Matlab simulation shows that the adaptive fuzzy-PID controller is better than normal PID controller in controlling the system. 4. Did the research on bilateral servo control strategies of telerobot. Based on this, we emphasized on the problems of traditional control strategies, such as the master and slave manipulator can not follow each other well and force feedback exists concussion when the slave manipulator touch the rigid object. In order to slove the problems, a new bilateral servo control strategy was discussed to control the telerobotic system. Through the analysis it can be seen that this new strategy is feasible and reasonable.5. Applied the new type bilateral servo control to the experiment system of 4-DOF electro-hydraulic servo telerobot, and three kinds of load were given to the experiment system: naught load, elasticity load and rigidity load. Then analysed the results of the experiment and the characteristics of the control strategy. The experiment shows that the new type control strategy could make the operator feel the movement of the slave manipulator in time and make the force feedback concussion softer than the other strategies. The experiment proved that the new type control strategy is reasonable. The new type control strategy will provide a new direction for the research of bilateral servo control.The 4-DOF electro-hydraulic servo telerobotic system can make the operator feel the dynamic reciprocity between the slave manipulator and object, so the teletobot can accomplish the task under inaccessible environment. The research and the experiment on the bilateral servo control strategies of the electro-hydraulic telerobot with telepresences provide a kind of reference and have practical significance. |
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