Control system for an automatic transmission testing device

Claim 1

A control system for a testing device for automatic transmissions, including a prime mover torque source to supply torque to the input shaft of an automatic transmission under test, and a simulated load to subject to load the output shaft of said automatic transmission, to simulate the operating conditions of an actual automobile, comprising: an input shaft side torque controlling feedback loop including a torque reference signal producing means which provides a torque reference signal for controlling the torque applied to the input shaft of said test transmission by said prime mover torque source, a torque detector which produces an actual torque signal corresponding to the actual torque being applied to the input shaft of said test transmission by said prime mover torque source, and a torque computer which compares said torque reference signal and said actual torque signal to control the torque applied to said input shaft of said test transmission at a value determined by said torque reference signal producing means; and an output shaft side speed controlling feedback loop including a speed reference signal producing means which provides a speed reference signal for controlling the speed of the output shaft of said test transmission by means of said simulated load, a speed detector which produces an actual speed signal corresponding to the actual speed of said output shaft of said test transmission, and a speed computer which compares said speed reference signal and said actual speed signal to control the speed of the output shaft of said test transmission by means of said simulated load, whereby the speed of the output shaft of said test transmission is maintained substantially constant at a gear shift point, in simulation of the actual circumstances of an actual automobile application, regardless of the change in speed of the prime mover torque source that results from the different gear ratios before and after the gear shift.