ZF Automotive UK Limited

A dual motor drive assembly comprising a housing, a shaft rotatably mounted with respect to the housing, a first gear connected to and configured to rotate with the shaft, first and second motor circuits, each motor circuit including a motor having an output driving a respective output gear, the output gears being engaged with the first gear, a control circuit adapted to allocate independent torque demands to each of the first and second motors to cause a net torque to be applied to the shaft comprising the sum of the torques applied by the two motors, and a processing circuit adapted to estimate the level of load independent mechanical friction of the system by applying torque demands to the two motors.

The disclosure describes a housing cover unit for a transmission and power steering drive housing, comprising a housing cover and a control unit for regulating the position and/or speed of a power steering drive. To this end, the control unit is arranged on and attached to the housing cover. Also shown is a steering unit for a vehicle.

An electric motor includes a stator and a rotor. The stator carries a plurality of phase windings and the rotor carries a plurality of magnet poles and is connected to a shaft. The stator has a yoke with a plurality of teeth. Each tooth has a stem and a tooth tip that is located at the end of the stem closest to the rotor. The region of the motor in which the tooth tips and the magnets directly face one another defines a cylindrical active magnetic region that bounds the magnetic flux that passes radially between the magnets of the rotor and the tips of the teeth of the stator. A sleeve of electrically conductive material is located between the inwardly facing tips of the stator teeth and the rotor. The sleeve provides a flux path that extends axially along the motor bore so that rotation of the rotor generates eddy currents within the sleeve that resist rotor rotation. The conductive sleeve has an axial length that is longer than the axial length of the active magnetic region and is positioned such that at least one end of the sleeve protrudes axially beyond the adjacent axial end of the active magnetic region.

A dual motor drive assembly comprises a housing, a shaft rotatably mounted with respect to the housing, a first gear connected to and configured to rotate with the shaft, and first and second motors, each having an output driving a respective output gear, the output gears being engaged with the first gear, in which each motor comprises a permanent magnet motor that has the same number of poles and stators such that each motor produces the same pattern of cogging torque over a complete mechanical revolution of the motor.

A motor drive circuit comprising: a motor bridge, comprising a bridge arm comprising upper and lower switches for each motor phase, which may be selectively closed to modulate voltage applied to the respective phases to drive signals from a motor control circuit, at least one solid-state-phase-isolation-relay (SSPIR) provided in series in an electrical path connecting a respective phase of the motor to a respective bridge arm, the SSPIR being closed in normal operation so that current can flow in the phase and held open in a fault mode of operation to prevent current flow, a monitoring arrangement for monitoring a current waveform in the phase to identify when it is safe to open the SSPIR without causing damage to the SSPIR due to an avalanche mode, and a control circuit that applies a voltage to each SSPIR that is sufficient to hold the SSPIR closed in normal operation is only opened when the current is in a safe operational area.

A motor circuit incorporated into a control system for a motor, in which the motor circuit comprises: a current determination stage arranged to generate a current demand signal in response to a torque demanded of the motor; a feedback loop comprising: a detector stage including a means for determining one or more operational values from the motor; and a current controller configured to calculate an error signal using one or more operational values from the detector stage and the current demand signal from the current determination stage; and a feedforward path comprising: a voltage controller configured to calculate a voltage demand signal from the current demand signal and one or more operational values from the motor, wherein the voltage controller comprises a first bandwidth filter, and wherein the current controller is configured to combine the error signal and the voltage demand signal to produce a signal for the motor.

An automotive vehicle control circuit can include a PID Controller that receives at an input a set point signal for the closed-loop control system and provides as an output a control signal that is fed to the motion control system. The PID controller is arranged in a closed-loop configuration with the motion control system to minimise an error value indicative of the difference between the demanded behaviour of the motion control system as indicated by the demand signal and the actual behaviour of the motion control system. The control circuit can include a neural network which has an input layer of neurons, at least one hidden layer of neurons, and an output layer comprising at least one output neuron, in which the neural network comprises a feedforward neural network that receives at the input layer of input neurons the demand signal, the drive signal output from the controller and the error value. The neural network is configured to determine one or more of the P gain, I gain and D gain terms used by the PID controller, and the neural network receives as a feedforward term at least one additional discrete environmental variable.

A lane keep assist system for an automotive vehicle includes an electric power steering assembly that is responsive to an output of the control system, the motor applying a torque to a part of a steering gear to steer the vehicle along a highway. The lane keep assist system assists a driver in keeping the vehicle in a lane of a highway, in which the control circuit comprises A PID Controller which receives at an input a target lane position for the closed-loop control system and provides as an output a control signal for a motor of the electric power steering assembly. The controller is arranged in a closed loop with the motor configured to minimise an error value indicative of the difference between the target lane position and the actual lane position of the vehicle.

A method of controlling an electric steering system having a multiple phase permanent magnet electric motor having a plurality of motor phases that in normal operation applies a torque to a part of the system connected to the road wheels to control the steering angle of the road wheels, the motor being driven by a bridge circuit that includes a set of switches that can be opened and closed to selectively connect each phase to a supply voltage of a power supply or to a ground in response to signals output from a bridge driver circuit, the method comprising, in an event of a fault that prevents the motor applying a torque that enables the roadwheels to be steered, operating switches of the bridge circuit independent of the bridge driver to short each phase of the motor so as to dampen the rotation of the motor and at the same time turn of the power supply to the bridge circuit.

A dual motor drive assembly comprising a housing, a shaft rotatably mounted with respect to the housing, a first gear connected to and configured to rotate with the shaft, first and second motors, each having an output driving a respective output gear, the output gears being engaged with the first gear, an allocation arrangement for allocating torque demands to each of the first and second motors, a target friction detection arrangement for determining a target friction, a calculation arrangement for calculating a mechanical friction, wherein the target friction and mechanical friction are compared, and wherein the mechanical friction is modified to meet the target friction by varying the difference between the two motor torque demands when the two motor torques are in opposing directions.