Design and Analysis of Novel Limb and End-effector Mechanisms for a Highly Capable Quadruped Robot

Quadruped robots are versatile locomotion platforms capable of a variety of manipulation tasks. For each operating environment, the quadruped's choice of kinematic design, actuators, and end-effectors requires tuning and optimization. This research introduces geometrically enhanced designs for limb mechanisms and magnetic variable stiffness end-effectors for a ship-board quadruped platform, SORREL. The choice of kinematics in quadrupeds is highly dependent on the gait and certain leg designs might be more prone to waste power. Traditional robots, design their kinematics based on the actuator being a single unit consisting of a motor and a gearbox, overlooking the effects of their relative positions on the limb kinematics. A new method was developed for designing the leg kinematics by decoupling the design of the gearbox and the motor. This method gives more freedom in the design of the kinematics and allows for a wider range of configurations best fit for the required task. The quadruped leg design presented in this work has both actuators collocated at the hip in a parallel configuration; however, the gearbox of the knee motor is relocated from the hip to the knee joint. This seemingly simple modification significantly reduces the mechanical antagonism and motor losses and increases the stiffness of the leg. Quadrupeds perform manipulation and grasping through task-specific actuators. These actuators need to interact with the environment safely while maintaining accurate force control capabilities. More specifically, SORELL needs to be equipped with gripper modules to deal with varying tasks such as typing on keyboards, precision manipulation of electronics, and general pick and place. Most grippers used in manipulators are based on stiff positioned-controlled actuators which provide accuracy but require bulky and expensive Force/Torque (FT) sensors for force control. Additionally, traditional grippers struggle with delicate handling tasks and pose safety risks due