|For the competition, Fortis Saxonia e. V. Chemnitz developed a new fuel cell vehicle, the Sax 2, which started in the prototype category.
Elmo Motion Control GmbH sponsored the Sax 2 eco car project at the Chemnitz University of Technology (CUT) and provided the team with Elmo's Harmonica compact servo drivers. Two Harmonica mini servo drivers control the rear-wheel steering system of the Sax 2.
The standard steering column was replaced by a driver-controlled analog joystick which sends signals to the Harmonica servo drivers used to control the back wheel of the Sax 2.
One of the main advantages of SbW technology is the small amount of space that is required for moving the joystick. Maximum flexibility is achieved by placing the joystick in the cockpit, which also allows for a very narrow chassis design: In turn, the narrow chassis minimizes the front surface and air resistance.
The angle and speed of turning the “steering wheel” is dependent on the actual speed of the vehicle, but because the center of gravity of the Sax 2 is very high, the danger of rollover due to a steering fault or error has been minimized via SbW. Additional software was used to reduce the risk of the vehicle overturning.
The overall system is powered by a hydrogen fuel cell system.
The implementation of a Stability Control Sensor is planned for the future.