For the conflict between manipulation safety and performance of teleoperation in unknown environment,a haptic flexible virtual fixture is proposed and implemented.It introduces a flexible coefficient to regulate the preference degree of robot moving towards the desired direction,which combines the advantages of manual control and off-line task planning. A certain manipulation performance can be obtained,and the ability to avoid obstacles in the off-line task planning path is achieved to guarantee the teleoperation safety.Furthermore,the virtual force feedback is integrated into the flexible virtual fixture to enhance the manipulation performance.The experimental results of sine curve tracking show that the proposed method decreases the average tracking error and the task completion time,and the manipulation safety and performance are obtained during the unknown environment teleoperation.
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