Investigation into Energy Efficiency and Regeneration in an Electric Prosthetic Knee

Powered lower limb prosthesis are facing energy and efficiency challenges. This article presents an investigation into reducing the energy losses and increasing the efficiencies of energy regeneration for a powered prosthetic knee during level ground walking. The results showed that the regeneration and overall system efficiencies would dramatically increase if the negative mechanical load in the braking quadrants are within the regenerative zone of the motor. This approach reduced the energy losses in the stance and swing phases and increased the possibility of harvesting more negative mechanical energy during level ground walking

Robotic Pseudo-Dynamic Testing (RPsDT) of Contact-Impact Scenarios

This paper presents a hybrid test method that enables the investigation of contact-impact scenarios in complex systems using kinematically versatile, off-the-shelf industrial robots. Based on the pseudo-dynamic test method, the technique conducts tests on an enlarged time scale, thereby circumventing control rate and response time limitations of the transfer system. An initial exploratory study of a drop test demonstrates that non-rate dependant effects including non-linear stiffness and structural hysteresis can be captured accurately while limitations result from the neglect of rate- and time-dependant effects such as viscous damping and creep. Future work will apply the new method to contact scenarios in air-to-air refuelling

Robotic Minimally Invasive Tools for Restricted Access Confined Spaces

A study has been performed in the design and fabrication of deployable borehole robots into confined spaces. Three robot systems have been developed to perform a visual survey of a subterranean space where for any reason humans could not enter. A 12mm diameter snake arm was designed with a focus on the cable tensions and the failure modes for the components that make the snake arm. An iterative solver was developed to model the snake arm and algorithmically calculate the snake arms optimal length with consideration of the failure modes. A robot was developed to extend the range capabilities of borehole robots using reconfigurable borehole robots based around established actuation and manufacturing techniques. The expected distance and weight requirements of the robot are calculated alongside the forces the robot is required to generate in order to achieve them. The whegged design incorporated into the tracks is also analysed to measure the capability of the robot over rough terrain. Finally, the experiments to find the actual driving forces of the tracks are performed and used to calculate the actual range of the robot in comparison to the target range. The potential of reconfigurable mobile robots for deployment through boreholes is limited by the requirement for conventional gears, motors, and joints. This chapter explores the use of smart materials and innovative manufacturing techniques to form a novel concept of a self-folding robotic joint for a self-assembling robotic system. The design uses shape memory alloys fabricated in laminate structures with heaters to create folding structures