Using COTS to Construct a High Performance Robot Arm

Abstract

Abstract-In this paper we present a design study and technical specifications of a high performance robotic manipulator to be used for ball catching experiments using commercial off-the-shelf (COTS) components. Early evaluation shows that very good performance can be achieved using standardized PowerCube actuator modules from Amtec and a standard workstation using CAN bus communication. Implementation issues of low-level control and software platform are also described, as well as early experimental evaluation of the system.

Teleoperation for a ball-catching task with significant dynamics

“…These modules are available off the shelf and allow for rapid prototyping. In addition, the modules have a builtin controller that can be used for embedded safety and low-level control (Smith & Christensen, 2007).…”

Trajectory tracking control of a 6-degree-of-freedom robot arm using nonlinear optimization

“…The layout of the kinematic structure is the first main issue to solve for a desired manipulation task. To achieve fast trajectory tracking, a published configuration [7] is used which is designed for ball catching purposes using same type but stronger motors. The robot is mounted on the top of a self-designed support made from steel plates and tube to maximize work space area and rigidity.…”

“…From control point of view, each joint can be actuated and measured as a discrete-time system through one 1 Mbit/sec CAN bus. The overheating reported in [7] was not experienced, because the average read/access cycle period in each module is only about 5 ms due to the shared bus. The PowerCubes, like many other industrial type modular robotic components, use local PID controllers for position or velocity control.…”

“…Average running time is measured to be 0.4 ms on Windows XP operating system with a Core Duo 3.6 GHz CPU. For comparison, the accessible algorithm on the Popeye robot website [7] under same conditions but in MATLAB environment executed in about 0.2 ms.…”

Minimum jerk based prediction of user actions for a ball catching task

“…The ball is caught in a cardboard cylinder with a diameter of 14 cm, which means that the spatial precision of the catch must be within 7 cm for the center of gravity of the ball to fall within the cylinder. A detailed description of the manipulator and the catching task can be found in [4] and of the control setup and internet time delay handling in [5]. Details of the user interface are described in Section V.…”