Smart Wheel

Indigo's core technoogy is called the "Smart Wheel." It is a hub-mounted axial flux motor which is arranged in a way to deliver both traction to the wheel and active suspension force. The active suspenion counteracts the addional unsprung mass from the hub motor giving the vehicle a ride quality similar to a traditionial suspenion. I was involved with two generations of suspensions. My role consisted of design and analysis of the knuckle, linkages, bearings, and wheel. I also supported the motor team with thermal and structural support for the motor design.

I was deeply involved in the design of the differential linkage mechanism that allows the motor to have two controlled degrees of freedom. The system is challenging because there is limited space to package, but there are still high inertial and motor loads that the parts must survive. The ideal linkage keeps the motion ratio between the two stators constant through out the extent of the suspension travel. To optimize this design, I used MATLAB to analyze thousands of linkages geometries to arrive at a solution that would package and deliver the best active suspension performance.

I used a dynamic model to simulate impact cases and the control forces needed to provide a comfortable ride on a rough road. These loads were then used to structurally design the links to ensure they were stiff under load as well as strong enough to survive peak loads. One of the links, the torque bar, transmits high torques from one stator to the other. I initially used hand calculations to size a spline according to DIN 5480 to transmit this torque; however, since there is also bending through these splines, I further refined the design using FEA. The design was validated on a test rig and achieved millions of cycles.

Corner Architecture

I was also involved with the architecture of the latest design of the corner. This including leading our team through analysis of different concepts and layouts to downselect the best design for our requirements.