Abstract: An interface system is presented, which prevents operational interference between a vehicle power door and a ramp of an access system by interrupting power to the motors and actuators responsible for operating the door. The interface system includes a relay system that does not interrupt, read, signal, or otherwise interfere with the communication lines between a body control unit, door control unit, or remote control transmitter or receiver. Thus, the interface system functions without the need to receive and transmit signals on the vehicle's communication bus. The interface system enables the ramp controller of the access system to be a separate module, which controls the ramp and kneel functions, because the only input the ramp controller provides to the power door system is to a ground signal that mimics that of a switch included in the vehicle.

Abstract: A permanent magnet synchronous motor is controlled using d-axis current and q-axis current along with respective d-current and q-current feedback loops. The speed and position of the motor are determined by injecting a first signal into the d-axis current and observing the response in the q-current feedback loop. Part of the q-current feedback signal is demodulated with a second signal which is 90 degrees out of phase from the first signal. The demodulated signal is preferably sent through a low pass filter before being received by an observer controller. The observer controller outputs a position estimate which is used to modify the d-current feedback signal and a speed estimate which is used to modify the q-axis current.

Abstract: In a method and an apparatus for controlling a motor, one type or a plurality of types of weakening current are previously set, a first torque command current determined from a speed deviation between a speed command to the motor and the present speed of the motor is compared with torque currents corresponding the torques, so that a second torque command current and a weakening current are determined and outputted depending on which range of the torque currents corresponding the torques the first torque command current falls upon. Thus, the second torque command current and the weakening current can be determined simply and efficiently.

Abstract: A circuit for generating a signal proportional to the average current of an inductive load supplied from a supply of intermittent electrical power and having a free-wheeling path through which load current flows during periods in which the load is not connected to the power supply, includes means to provide a first signal which is a function of the current in the free-wheeling path and second means to provide a second signal which is a function of the supply-load current. By appropriately combining the two signals an output proportional to the average load current is obtained. The output signal can be utilized for control functions such as controlling the operation of switching devices which, in turn, control the application of electrical power to a d.c. motor.