Automotive vehicle performance test stand system and performance measuring method

Test stand system for the dynamic measurement of performance of automotive vehicles and the engines thereof using a roll test stand comprising

• rollers with which at least a driven wheel of the vehicle is in engagement;
• an inertia flywheel connected to at least one of the rollers for acceleration by the engine of the vehicle via the wheels of the vehicle through the drive train of the vehicle and for deceleration upon interruption of driving connection from the engine of the wheels;
• means sensing an operating parameter related to speed, and change of speed, and providing a speed signal;
• means sensing tractive effort supplied by the wheels upon acceleration and traction losses upon deceleration, and providing a torque signal;
• combining means (22) responsive to the output of said traction sensing means and said speed-related sensing means to deliver a combined output signal representative of engine performance;
• a correction network (23) providing a correction signal as commanded in said correction network and representative of correction factors connected to the combining means (22) to introduce additional correction factors thereto to be multiplied with the speed-related and traction-related signals;
• means generating a test speed signal;
• an acceleration memory means (24) and a deceleration memory means (25) comprising a storage memory connected to store the combined output signal and controlled by said test speed signal to store the combined output signal (a) when the test speed is reached in an acceleration phase and, to store again (b) the combined output signal when the test speed is reached during a deceleration phase, the memory forming a respective sum or difference value of the respectively stored quantities at said test speed, as controlled by the test speed signal;
• and indicator means (32) connected to the output of said storage memory and indicating the sum or difference of the stored value thereof.

Method of dynamically testing the performance of automotive vehicles and of the engines thereof

• using a test stand system
• having rollers with which the driven wheels of the vehicle are in engagement;
• inertia flywheel means connected to at least one of the rollers for acceleration by the engine of the vehicle via the wheels of the vehicle through the drive train of the vehicle, and for subsequent deceleration upon interruption of driving connection between the engine and the vehicle wheels;
• means (14, 15, 16;
• 18, 19, 20;
• 17) sensing an operating parameter related to speed and change thereof and providing a measured speed-related signal;
• means (17;
• 21) sensing traction effort supplied by the wheels upon acceleration, and traction losses upon deceleration and providing a measured torque-related signal;
• and combining means responsive to the measured speed-related signal and to the measured torque-related signal and deriving a combined output signal representative of engine performance,
• and including the steps of:
• connecting the drive train of the engine and accelerating the engine while sensing and measuring the speed-related signal and the traction-related signal;
• storing a combined first output signal derived during acceleration from said measured signals at a first predetermined engine speed;
• then disconnecting the engine to provide for deceleration and driving of the wheels of the vehicle by the inertia flywheel while sensing and measuring the speed-related signal and the torque-related signal;
• storing a combined second output signal derived during deceleration from said measured signals at said first predetermined engine speed;
• summing the combined first and second output signals to determine performance and power output of the engine by generating a signal representative of losses dependent upon at least one of:
• traction losses;
• speed-related losses;
• constant losses.