The Transmission Test Cell is an example of high-tech design. The solutions adopted in this system are highly innovative and define a clear-cut divide between the old approach to transmission tests and the modern era of driveline testing.
The transmission assembly is tested by means of three three-phase asynchronous motors controlled by a regenerative inverter. The first motor simulates the torque normally generated by the car engine, and the other two absorb the torque from the two differential output shafts, simulating in actual fact the braking action of the vehicle. This effect is obtained through a simulation of vehicle inertia.

The gear lever and the clutch are actuated by DREAMS, Control Sistem’s well-tested automatic drive system. The motors are controlled by the DBStr (“Dynamic Braking System transmission”) automation box produced by Control Sistem. The Transmission Testing Cell is used to test both automotive gearboxes and drive axles. In the latter case, the motor that delivers torque must be positioned in a different manner than in the gearbox configuration. This rearrangement is accomplished with great ease by means of air cushions installed beneath the mechanical supporting system. In this manner, the assembly to be tested can be moved by having it levitate over a fine layer of air. The automation and control software runs in the INT9000 environment developed by Control Sistem. It supervises and controls both the standard peripherals connected (DREAMS and DBStr) and the micro PLCs that manage all the auxiliary circuits of the testing room.


ADVANTAGES ARISING FROM THE USE OF ELECTRIC MOTORS

- The simulation of vehicle inertia does away with the need to fit bulky flywheels on the countershafts;
- Electric motors make it possible to execute dynamic tests (reproduce real dynamic stress conditions on the gearbox);
- The electric motor on the main shaft replaces the car engine, which means the testing room does not have to be equipped with auxiliary engine interlocking units, such as lubricant and fuel feed systems, water cooling system, etc.;
- Thanks to the use of regenerative inverters, the energy dissipated by the two motors applied to the countershafts is converted into electric energy which is used to power the first motor. This strategy enables the overall energy consumption to be greatly reduced.