Research On Telerobot With Force Feedback

Teleoperation systems with master-slave robots at the core can be complexmanipulated in uncertain or extreme environments (such as space, seabed,radialization, battlefield, etc.). The quality of operation is correlation with theability of getting information (such as force, vision, etc.) about the slave side. Thedynamic reciprocity between robots and operated objects can be felt byteleoperation system on account of the force telepresence and vision telepresence,which make the operator accomplish complicated and exact operation. Nowadaysthe research of technology related to telepresence is gaining greater attention.Vision telepresence can provide most information for teleoperations, it is ofgreat help for the human operators'cognition to the environments being operated.When robots contact the environment and only vision telepresence is provided,human operators cannot acquire the real sense. Only with the guidance of forcetelepresence can human operators accomplish these complex and fine tasks.Experiments on teleoperation systems also indicate that force and tangency sensescan greatly enhance the efficiency and accuracy of teleoperation systems. Due tothese, force telepresence may provide great help for teleoperation systems, and itcan greatly enhance manipulation performance.In this paper, we have set up a telerobot system hydraulically droved withforce feedback which is called single-DOF bilateral servo system after analyzingthe telerobot systems with telepresence, especially those with force telepresence inhome and abroad. The system has a symmetrical structure, whose master and slavesubsystem is the same in form. To speak of the function of this robot system, itmainly comprises electron hydraulic proportional control subsystem, bilateralservo control subsystem. We have discussed the structures and realization of thefunctions of all subsystems at length built on those mentioned above.Aimed to the characters of the telerobots under electron hydraulic servocontrol, we have researched the traits of the hydraulic system and comparativelyanalyzed the typical bilateral servo control strategies. As to the problem of forcefeedback existed in teleoperation systems under the complex control of force andposition such as the greatness of the strike in force feedback and the bad capabilityof following in master-slave position control, we have brought forward a newbilateral servo control scheme and studied out experiment scheme. Therationality of the position controller is validated through the experiment ofmaster-slave position control. And the feasibility of the control scheme and thevalidity of force controller are validated through the experiment of force feedback.Combining the researches of theory and experiments, we have accomplishedthe main research tasks as follows:1. We have set up a single-DOF telerobot system with force feedback basedon electron hydraulic servo control system and it has the capacity of teleoperation,high precision position control and force feedback. The establishment of thissystem and the application of new bilateral servo control strategy provide practiceaccording for establishment of complicated teleoperation system and basis forresearches of bilateral servo control strategy.2. We have designed single-DOF master controller and slave controllerbased on electron hydraulic proportional control. In order to get favorable dynamicand static performance for the hydraulic cylinders, we have designed PID serialcorrection controller and got the parameters of the controllers through the methodof 2-rank engineering devise. We have realized high accurate position controlthrough the designation of master controller. We have realized force telepresencethrough the designation of slave controller. Applying the new force-positionbilateral servo control algorithm advanced in this paper, with the differencebetween the force of the master and slave systems being the controlling signalwhich controls the movement of the hydraulic cylinder in the slave system, wehave made the displacement of the hydraulic cylinder in the master system followaccurately that in the slave. This new bilateral servo scheme is validated to haveperfect effect in master-slave position control and force feedback. This strategycan make human operators grasp not only the moving status of the slave but alsothe interference of it, while the working resistance can be sensed at the same time.And it can also eliminate the strike in force feedback to some extend.3. The research and development of bilateral servo control strategies havebeen introduced in detail. By compares of working characters of the three bilateralservo control strategies in both motor and electron hydraulic controlled robots,especially the mended bilateral servo control strategies and the problems existed inthe bilateral servo control of the latter. And the new bilateral servo control strategy...