Zf Automotive UK Limited

Trw Lucasvarity Electric Steering Limited

Trw Limited

Lucas Industries Public Limited Company

Other

Zf Friedrichshafen Ag

Zf Automotive Germany Gmbh

Russell Wilson-Jones

Mark Anthony Wilkes

John M Ironside

Steven John Horton

Michael Appleyard

David Julian Moule

Anthony Walter Burton

Aleksejs Semjonovs

Timothy Buttery

Simon David Stevens

Andrew James Stephen Williams

Nigel Peter Smith

Timothy Sworn

Birk Junghanns

Raglan Horatio Tribe

Geoffrey Tullener

Lukas Schemmel

Christos Prevezianos

Lorenz Graeff

Andrew Reynolds

Thomas Haines

Sebastian Granville-Edmunds

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.

Dual motor drive assembly

A steering column assembly for a vehicle comprises a steering column mounted for rotation about its longitudinal axis and configured for attachment to a steering wheel at one end; a first gear connected to the steering column at a location spaced from the end where the steering wheel may be attached and configured to rotate with the steering column; first and second motors; first and second worm screws connected to and rotatable with an output of the first and second motors respectively and engaged with the first gear; and a control arrangement configured to operate the first and second motors. The control arrangement comprises a circuit board located between the first and second worm screws and their respective motors. The circuit board comprises a motor output position sensor for each of the first and second motors.

Steering column assembly for a vehicle

A dual motor drive assembly comprising a housing, a shaft rotatably mounted to the housing, a first gear rotatably connected to the shaft, first and second motors, each having an output driving a respective output gear, the output gears being engaged with the first gear, a torque allocation arrangement for allocating torque demands to each of the first and second motors, a measurement arrangement for measuring first and second temperature relating to the first and second motors respectively, a torque limit allocation arrangement for allocating a maximum torque limit based on the first and second temperature respectively, wherein a maximum total torque is equal to the sum of maximum torque limits of the first and second motors, wherein in a first mode the allocated torque demand to each of the motors is to provide opposing torques to the shaft, and in a second mode to provide torques in the same direction to the shaft, wherein the torque demand allocations change from the first mode to the second mode at a threshold total torque value, and the threshold total torque value is adjustable based on the maximum total torque.

An electric power steering system includes: a steering bar, an electric motor, a linear position sensor, and a sensing means. The steering bar is mechanically connected at each opposing end to a respective wheel carrier. The linear position sensor having one elongate feature that extends diagonally along a length of the steering bar such that it is inclined relative to the axis of the steering bar. The sensing means faces the steering bar and at any given time observes only a slice of the elongate feature that extends across the full width of the feature and along only a part of the length of the feature. The sensing means generates a signal that varies depending on the pattern formed by the feature and adjacent portions of the steering bar that is observed by the sensing means.

Electric power steering

A travel limiter for a rotatable steering column of a vehicle comprises: a housing; an elongate threaded member rotatably mounted about its longitudinal axis within the housing; a nut member threadedly mounted on the elongate threaded member, the exterior of the nut member comprising a toothed gear; connector for connection of a rotatable steering column of a vehicle to the elongate threaded member, whereby the steering column and the threaded member are constrained to rotate together; end stops which engage with the nut member to define the maximum axial displacement of the nut member along the elongate threaded member in both directions; a drive motor having an output shaft configured to rotate an output gear member meshed with the gear on the exterior of the nut member; and a controller configured to control the operation of the drive motor.

Travel limiter for a vehicle steering column

A handwheel actuator assemblyfor a steer by wire steering system of a vehicle is disclosed. The assemblycomprises a steering wheeland a feedback torque generator. The steering wheelhas at least one hand grip portion rotatable around an axis of rotation of the steering wheelwhich can be gripped by a driver and a hubthat supports the hand grip portion. The feedback torque generator comprises an electric motor which has a statorand a rotor. The rotoris directly or indirectly fixed to and rotates with the hub of the steering wheeland the statoris secured to a fixed part of the vehicle body such that it cannot rotate relative to the vehicle body. The motor comprises a brushless permanent magnet Vernier motor.

Handwheel actuator assembly

A steering column assembly is disclosed that comprises: an elongate rotatable steering column, a displacement motor, a torque feedback motor; an engagement mechanism and a control. The steering column is configured at one end for attachment of a steering member and is displaceable along its longitudinal axis between a withdrawn, stowed position in which the steering function of the steering column is inhibited and an extended, deployed position in which the steering function of the steering column can be enabled. The displacement motor displaces the steering column between the stowed and deployed positions. The torque feedback motor is connected to the steering column and by which the steering column is rotatable. The engagement mechanism is engaged when the steering column is in the stowed position and limits the angular displacement of the steering column to a predetermined value. A control is configured to control the operation of the displacement motor and torque feedback motor and to inhibit and enable the steering function of the steering column.

Steering column assembly

A combined motor and gearbox assembly for an electric power steering system comprising an electric motor, a gearbox which includes a gearset that is connected on an input part to a rotor of the motor and in use is connected on an output part at least indirectly to a steering column shaft to transfer torque from the motor rotor to the steering column shaft, a motor drive circuit, a gearbox housing which in use accommodates the gearset of the gearbox, the electric motor including a motor housing, and a baseplate which connects an end face of the gearbox housing to an end face of the gearbox housing and which supports the drive circuit. At least one bolt having a stem passes through a central hole in a tubular rivet that secures the motor housing to the baseplate, the bolt securing the baseplate to the gearbox housing.

Electric power assisted steering

A steering torque feedback assembly for a vehicle steering column includes a housing, a first gear rotatably mounted within the housing about a first rotatable axis and being configured to rotate with, or being connected to, a vehicle steering column, first and second electric motors mounted within the housing, each having a rotatable output shaft, second and third gears rotatably mounted within the housing and engaged with the first gear, and first and second reduction gearing connecting the output of the first and second motors and a respective one of the second and third gears.

Torque feedback assembly for a vehicle steering column

A handwheel actuator assembly includes a handwheel shaft configured to receive a handwheel; a feedback device operable to provide a variable level of resistance to rotation of the handwheel shaft; and a handwheel shaft position sensor operable to sense an angular position of the handwheel shaft. The handwheel shaft position sensor may be mounted on a circuit board. The circuit may comprise a controller that is configured to receive signals from the handwheel shaft position sensor.

A gearbox assembly for an electric power assisted steering apparatus comprises a gearbox housing which houses a worm shaft and a gear wheel, the worm shaft being supported relative to the housing by a main bearing assembly at an end closest to the motor and by a tail bearing assembly at an end furthest from the motor. The main bearing assembly comprises an inner race and an outer race separated by bearing elements, the outer race being supported by a carrier that is supported by an axle that is in turn secured to gearbox housing, the axle defining a pivot axis for the worm shaft that is located on the side of the worm shaft closest to the wheel gear and extends in a direction orthogonal to the axis of the worm shaft and parallel to the axis of the wheel gear.

Gearbox assembly for an electric power steering assembly

A method of controlling an electric motor in an electric power assisted steering system, the motor being arranged so as to apply a force to part of a steering mechanism of a vehicle, in which the method comprises calculating a force demand indicative of an assistance force dependent upon the torque applied by a user (T) to the steering mechanism that it is to be applied to the steering mechanism to reduce the exertion required by the user to steer the vehicle; combining the force demand with an overlay force demand (T) indicative of a force which it is desired to overlay over the assistance force, to generate a combined assistance force (T); and controlling the motor according to the combined assistance force, such that together with the force applied by the user, a total force is applied to the steering mechanism, in which, in order to generate the combined assistance force the torque applied by the user is subjected to a non-linear boost function and in which the overlay force demand is combined with the force demand such that, for an arbitrary change in the overlay force demand the change in the total force is independent of the torque applied by the user over a range of torques applied by the user.

Controlling motors in electric power assisted steering systems

An electric power assisted steering system comprises a torque sensor, a motor connected to a part of the steering system to provide motor torque to the steering system and a motor controller which is adapted to receive an output signal from the torque sensor and to generate a motor torque demand signal indicative of the torque to be applied by the motor to the steering system. The motor torque demand signal comprises a driver demand component dependent upon the torque applied by the driver; and a diagnostic component independent of the torque applied by the driver and which varies in value over time in a predetermined manner. The system further comprises a monitor that correlates the diagnostic component with the output signal and generates a signal indicating that the output signal is faulty if the correlation falls outside of a predefined range.

Electric power steering system

An electrical power-assisted steering system is disclosed comprising an electric motor connected through a gearbox to act on a steering mechanism of the vehicle, the electric motor having a plurality of phase windings connected to a star point and switching means provided in at least one phase of the motor, the switching means being movable between a closed position in which current is able to flow in the phase windings, and an open position which prevents current flowing in a respective phase winding. The system incorporates a safety circuit operative when a fault develops to smooth out the transition between the presence and absence of servo support in assisting and not assisting by providing a prescribed period of damped operation as part of a shut-down phase.

Electrical power-assisted steering systems

A method of calculating the position of the rotor of a motor ( ) in for example an electrical power assisted steering assembly is disclosed. The method comprises the steps of measuring the output shaft ( ) (i.e. steering column) position, and scaling the measured value to produce an estimated motor rotor position value. This estimated value will be relative to an arbitrary datum point, and so the method further includes steps of adding an offset value derived from low resolution measurements of rotor position obtained using Hall effect sensors provided on the motor. Offsets for compensating for backlash and (in a second embodiment) compliance can also be included. Thus, the method allows high resolution information from an output shaft sensor (e.g. a torque sensor with a position dependent output) to be combined with the low resolution output from the Hall effect sensors to produce a high resolution rotor position signal. A correction is also made to allow for &ldquo;staleness&rdquo; in the Hall effect sensor output when calculating the offsets by monitoring rotor speed.

Growing community of inventors

Stratford-Upon-Avon, United Kingdom

Russell Wilson-Jones