A human mimicking control strategy for robotic deburring of hard materials

ABSTRACT

This paper deals with the use of an industrial robot (IR) for the deburring of hard material items (i.e. cast iron items). The control strategies introduced in this paper aim to mimic the human behaviour during the manual deburring. On the basis of force feedback, provided from a 1-axis load cell, the nominal deburring trajectory is optimised and deformed making multiple repetitions. The deburring trajectory is repeated until completing the nominal deburring path. The removal of thin layers of materials allows the robot to operate at high feed rates avoiding spindle stall and without exciting elastics effects on the mechanical structure of the system. Furthermore, a method to automatically detect the force changepoints, related to the presence of a burr, without tuning force thresholds, is discussed. The human mimicking control strategy is compared with a standard industrial approach demonstrating a reduction of the task cycle time and an improvement of the finishing quality.

KEYWORDS:

• Deburring with robots
• human-mimicking control strategies
• hard material deburring
• changepoint detection

Acknowledgments

Special thanks to the technician of mechanics laboratory of CNR-ITIA involved in setting up the experiments.

Disclosure statement

No potential conflict of interest was reported by the authors.

Notes

1. The Robot Operating System (ROS) (OSRF 2017) is a flexible framework for writing robot software. ROS is nowadays a standard de-facto in robotic research.

2. ROS-industrial (ROS-Industrial 2017) is the industrial extension of ROS middleware. A ROS-I vendor specific driver, in this case COMAU, enables the control of industrial manipulator through ROS functionalities from an external PC with respect to the robot control system.

Additional information

Funding

This work was supported by the Flexicast EU project [EU-FP7-2012-NMP-ICT-FoF].