Impedance and teleoperated control of a mini-excavator

[With post-doctoral fellow Shahram Tafazoli and Ph.D student Keyvan Hashtrudi-Zaad . Supported by IRIS/PRECARN and an NSERC Equipment Grant.]

Impedance control of mini-excavator

In spite of the complex contact tasks they have to execute, conventional excavator-based machines are controlled in position mode. In this project, the forces exerted by the excavator arm hydraulic cylinders are measured using load pins or hydraulic pressures and used in a position-based impedance control scheme to alter the dynamic properties of the controlled arm. The impedance characteristics are defined in task space in the plane of the excavator arm. A comparison of leveling tasks in conventional position mode and impedance mode has been performed, showing the benefits of this more sophisticated control mode Results can be found in
[Salcudean et al, 1997].

Instrumented mini-excavator.

Teleoperated control of mini-excavator

The teleoperated control of excavator based machines has applications in the mining, forestry and construction industries. My particular interest in the area has been the force-feedback teleoperation of such machines [Parker et al, 1993], [Lawrence et al, 1995], [Salcudean et al, 1997], [Salcudean et al, 1998]. We have demonstrated the feasibility of several control schemes, and we are working on issues of scaling and control in velocity mode.

Virtual slave simulator for rate-control with force feedback.

CAT 325B feller-buncher

controlled, in velocity-control mode with force feedback, by the UBC maglev joystick.