In most testing scenarios, driver robot can improve the testing accuracy and reduce the testing time when it replaces human driver. In this paper, an innovative pedal actuator of driver robot based on flexible manipulator is designed. This pedal actuator of driver robot can save the driver cabin space by changing the shape of manipulator according to different vehicle models, so that the human driver can sit in the cabin, together with the driver robot, monitor the testing process and take over the driver robot when necessary.
The proposed pedal actuator of driver robot is composed of a flexible manipulator and end effector. The end effector which is respected to generate 500N pressure in maximum is based on ball screw pairs actuated by DC motor. The flexible manipulator is designed referring to 2-DOF universal joints. The designed prism shells around joint can improve rigidity of flexible manipulator under the condition of small size. Modular link design is used and every module has 2 degrees of freedoms. Its reaching range can be adjusted by increasing or decreasing the amount of modules. A three dimensional model has been constructed and the working principle of flexible manipulator is demonstrated in this paper. Simplified kinematics model of flexible manipulator is established, and the homogeneous coordinate transformation matrix and Denavit-Hartenberg convention are used to derive the kinematics equations. And the rotation angle of prism shell which is directly related to the servo motor angle is used to express the bending angle of the universal joint in the kinematics equations, so that it becomes straightforward and simple to solve the forward kinematics problem and control the manipulator.