| 摘要 |
A vehicle system (10) is provided. The vehicle system comprises an electrical DC motor (11) driving a load (12), such as a hydraulic pump, and a control system (100) for controlling the speed of the electrical motor (11). The control system (100) comprises a system (20) for monitoring and controlling the speed of the electric DC motor in view of a reference commutation signal (SR), wherein the electrical DC motor is associated with a drive current signal (ID), and wherein the drive current signal (ID) comprises information relating to the commutation signal of the electrical DC motor. The system (20) comprises a speed estimation unit (23) for estimating a commutation signal (SE) from the drive current signal (ID), said commutation signal (SE) corresponding to an estimated motor speed; a filter unit (25) configured to apply a first filter on the drive current signal (ID), said first filter being selected based on the estimated commutation signal (SE), thereby resulting in a filtered drive current signal, and a speed detector unit (26) for detecting the actual commutation signal (SM) from the filtered drive current signal. If the detection of the commutation signal (SM) is unsuccessful the speed estimation unit (23) is based upon the receipt of a signal (SM-NO) from the speed detector unit (26) configured to transmit an estimated commutation signal (SE) to a control unit (28), wherein the control unit is configured to provide a control signal comprising information of a comparison between the reference commutation signal (SR) and the estimated commutation signal (SE) and indicating a required updated drive signal (ID). |
