Test control and automation systems have been supplied for a wide range of automotive applications, in particular for drivetrain durability and endurance testing. Some typical test systems are outlined here.
Each computer system was designed to run a diesel engine in a development test cell according a user defined schedule. Automatic control of the throttle actuator and dynamometer, in a variety of modes, were used to achieve the required engine conditions. Central servers were employed to provide storage of all test schedules, test log data etc. and also to act as an arbitrator when access to one of the Emissions Carts was required by a test cell.
The system was designed to automate the running of a gearbox durability test rig so that unmanned endurance tests could be carried out safely. Signals being monitored include vibration, speeds, torques, and temperatures at various locations around the test bed.
In-depth checks on engines from the production line or returned by customers are undertaken in four test cells, each of which has a cell computer to control a throttle actuator and dynamometer. A supervisory machine is also used to act as a central file server and an arbitrator for an Emissions Cart.
The system was designed to automate the running of a high speed axle test rig so that unmanned endurance tests of the axle differential could be carried out safely. Controlled and emergency shutdown routines were implemented so that in the event of a failure of the axle or differential, the rig can be properly stopped and a shutdown history log is created for later analysis.
Diesel engine vehicles are equipped with specialized valves including EPM valves which act as exhaust brakes by controlling back pressure into the engine, and EGR valves which reduce emissions by re-circulating exhaust gasses.
To perform end of line test on a new range of valves the manufacturer wanted to replace their existing test rigs, which used high volume air pressure to replicate engine operating conditions. This required a large air reservoir and compressor installation which was not only expensive to operate but also occupied a large area of the manufacturing site.
New test rigs that use a low volume pneumatic system were designed with
the mechanical assembly of the rigs carried out by the customer and
Tascomp developing the PC based control and monitoring system.
