Contribution

Mechanical Design Optimization of a Pneumatically Actuated Parallel Kinematic Machine

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Abstract

The application field of motion simulation needs robotic platforms with a high level of dexterity payload. Therefore increasingly parallel manipulators/platforms are used as 3 to 6 degree-of-freedom constructions. The contradictory aim for high applicable forces and large workspace volumes necessitates an optimization of the mechanical construction. In contrast to common configurations the robot utilized here is a hexapod equipped with antagonistic type of pneumatic actuation, imitating the flexor-extensor principle of human muscles. A counter force is applied passively through a spring in the center point of the hexapod. This structure offers advantages for application as motion simulator such as little maintenance requirements and low cost assembly. Due to the direct correlation between actuator length and dynamics, the use of classical techniques for workspace evaluation in the area of design optimization is not applicable. The paper illustrates the optimal design of this parallel kinematic ma- chine concerning maximum workspace taking into account the dynamical system. The presented method ensures stability in the upper maximum possible position through an additional optimization of the maximum disturbance force. The resulting multi-objective optimization problem is solved by using an evolutionary algorithm with a Pareto approach. The introduced method for evaluating an adequate measure of the maximum workspace volume for parallel platforms is well suited in the application field of motion simulators. The optimal solutions of the Pareto front are evaluated and compared to the parameters used in the existing configuration of the platform at the Institute of Robotics.

Keywords: multi-objective optimization, parallel robots, design optimization, motion simulator, pneumatic actuation

How to Cite:

Springer, K., Gattringer, H. & Müller, A., (2025) “Mechanical Design Optimization of a Pneumatically Actuated Parallel Kinematic Machine”, ARW Proceedings 25(1), 13-18. doi: https://doi.org/10.34749/3061-0710.2025.2