Design of a Cable-Driven Auto-Charging Robot for Electric Vehicles

Abstract

With the increasing popularity of electric vehicles, low level of automation for charging process has become one of the main factors restricting the development of electric vehicles. Recently, auto-charging robots which have the ability to transform manual process plugging charging plugs into charging ports to automatic plugging-unplugging operation have arisen. This paper presents a 4-DOF cable-driven autocharging robot (CDACR) consisting of a 3-DOF cable-driven serial manipulator (CDSM) and a moving platform. In this design, the 3-DOF CDSM is actuated by six cables being routed through five disks fixed to the CDSM's rigid links. The end-effector of CDACR is a flexible plug that has the ability to withstand small elastic deformation. The control algorithm and the plugging-unplugging strategy were designed to respond to various parking situations with or without yaw error. This paper takes the lead in introducing the cable-driven robot into the field of automatic charging. Besides, through simulated charging experiments, the feasibility and effectiveness of using CDACR to realize auto-charging for electric vehicles has been demonstrated.INDEX TERMS Cable-driven robot, auto-charging robot, electric vehicles.

Robust Adaptive Control of Fully Constrained Cable-Driven Serial Manipulator with Multi-Segment Cables Using Cable Tension Sensor Measurements

“…The charging plug is connected to Link 3 as an end-effector. Hence, the DOF information can be given by Automatic charging robots for electric vehicles are a research field which has emerged in recent years [5,31,32]. Its purpose is to use robots to transform manual process plugging charging plugs into charging ports to an automatic plugging-unplugging operation, as shown in Figure 5.…”

“…The realisation of this kind of automation will free the charging workers from heavy and repetitive work. A complete automatic charging process is shown in Figure 7 in [ 5 ]. The task of the controller proposed in this paper is to ensure the movement accuracy of the two sub-processes from the starting position to the pre-plugging position and from the pre-plugging position to the plugging position.…”

“…Thus, CDSMs possess low stiffness, low weight, low moving mass and a large reachable workspace. Such robots can be applied in medical rehabilitation [ 2 ], assembly in a complex narrow cavity [ 3 , 4 ], automatic charging in electric vehicles [ 5 ], nuclear reactors [ 6 ], etc. The unidirectional nature of cable actuation (i.e., a cable can only pull and not push) necessitates all the cables be tensed.…”

“…This type of controller is suitable for scenarios where the robot must move slowly. One type of controller is based on both kinematic and dynamic models of the robot and uses the motor torque obtained from the latter as the feedforward compensation term, which, together with the proportional–integral–derivative (PID) feedback term of the motor position, forms the control input [ 5 , 13 ]. Another type of controller considers not only the positional and trajectory-tracking accuracy of the robot but also the distribution and precise tracking of cable tension.…”

Self-Calibration for the General Cable-Driven Serial Manipulator with Multi-Segment Cables

“…Cable-driven robots have been applied in many fields, for example, medical rehabilitation [1], assembly in a complex narrow cavity [2,3], automatic charging in electric vehicles [4], nuclear reactors [5], etc. High positioning and trajectory tracking accuracies is the basis of performing complex tasks.…”