Designs and Practical Control Methods for Soft Parallel Robots

The use of soft robotics is becoming an increasingly researched topic, since they can provide more flexibility in movements and increase safety when working with humans. However, they are more susceptible to modeling and manufacturing errors in the design. The objective of this thesis is two-fold, the first objective is to determine the benefits and limitations of using calibration tables that rely on the PWM signals instead of modeling as a control method. If calibration tables are not adequate to achieve a high level of precision. The second objective is to determine if using a tethered mobile robot in unison with a soft robotic arm is a viable control strategy and evaluating its limitations. These objectives were chosen since soft robotic manipulators are complex to control with difficult governing equations. The approaches in this thesis seek to circumvent these shortcomings. Two different soft robots are introduced, the first being a small robotic pollination end-effector used to pollinate blackberry flowers in a greenhouse, the second is a tendon driven soft robotic manipulator. Using a calibration table on the pollination end effector yielded high precision and repeatability. However, when extended to the larger tendon driven arm it caused a large overshoot of the goal with little repeatability. The speed of the trials was slowed down and augmented by a holonomic mobile robot which eliminated the overshoot and increased repeatability