MAE recently delivered a sophisticated Mobile Laboratory Tow Dynamometer for use in validating tractors to the Nebraska Tractor Test Drawbar Test. Previously MAE delivered the PTO test stand, which is used to perform the PTO portion of the Nebraska Tractor Test to the same customer. The Mobile Lab Tow Dynamometer consists of a modified extended cab class-8 over-the-road truck with a modified powertrain and adjustable front tongue assembly. The system is supplied with a tractor fuel measurement system to measure the pulling tractors fuel usage during testing. A weather Station is located in the dynamometer system to measure ambient temperature, relative humidity and barometric pressure, while a portable data pod located in the test tractor’s cab captures the tractor’s engine rpm, engine pressures & temperature. The system is also easily expanded to communicate with the tractor’s ECM.
The cab of the tow dynamometer was also modified with 4 custom air-ride chairs, a work station, alarge mounted plasma monitor, cabinets, and a laptop PC control system. The operator can adjust operating speed ranges right from the driver’s seat. A tractor to tow dynamometer communication system is installed so the system drivers can communicate to each other. The towing hitch assembly has the ability to automatically adjust from 200 to 1,000 mm (8″ to 39″) and can be operated in an auto-follow mode during tow operation.
This sophisticated tow dynamometer was developed and optimized to meet our customer’s specific application and testing requirements. This included maximum continuous drawbar capacity in excess of 130,000 N (30,000 Lbs.) and continuously power absorption in excess of 200 kW (270 Hp). The customer’s requirements limited the speed from 0.5 to 30 km/hr (.3 to 18.6 mph). Future systems that require higher or different performance criteria can be easiliy developed with an optimized powertrain system for power performance up to 450 kW (600 Hp), drawbar performance up to 225,000 N (50,000Lb.) and speeds up to 110 km/hr (70 mph).