Steering system with magnetic torque overlay lash compensation
AssigneeSteering Solutions IP Holding Corporation
InventorJoel E. Birsching
Life of this patent
Estimating the term…
Abstract
Technical solutions for compensating for lash in a steering system are described. An example method includes determining a rack pressure value based on a driver torque value and a differential pressure across a rack of the steering system. The method also includes determining a compensation friction value based on a position of a handwheel of the steering system and a speed of a vehicle equipped with the steering system. The method also includes computing a pressure value based on the rack pressure value and the compensation friction value. The method also includes generating a torque command using the pressure value, the torque command being added to the driver assist torque for the steering system.
Claims20
A method for compensating for lash in a steering system, the method comprising:
- determining a rack pressure value based on a driver torque value and a differential pressure across a rack of the steering system;
- determining a compensation friction value based on a position of a handwheel of the steering system and a speed of a vehicle equipped with the steering system;
- computing a pressure value based on the rack pressure value and the compensation friction value, wherein computing the pressure value further comprises:
- determining a static pressure value based on the rack pressure value, wherein determining the static pressure value comprises multiplying the rack pressure value by a predetermined scaling factor and limiting a result of the multiplication by the compensation friction value;
- determining a dynamic pressure value based on a speed of the handwheel of the steering system;
- and
- adding the static pressure value and the dynamic pressure value to compute the pressure value;
- and
- generating a torque command using the pressure value, the torque command being added to the a driver assist torque for the steering system.
A steering system comprising a control module configured to:
- determine a rack pressure value based on a driver torque value and a differential pressure across a rack of a steering gear;
- determine a compensation friction value based on a position of a handwheel of the steering system and a vehicle speed;
- compute a pressure value based on the rack pressure value and the compensation friction value, wherein computing the pressure value further comprises:
- determining a static pressure value based on the rack pressure value, wherein determining the static pressure value comprises multiplying the rack pressure value by a predetermined scaling factor and limiting a result of the multiplication by the compensation friction value;
- determining a dynamic pressure value based on a speed of the handwheel of the steering system;
- and
- adding the static pressure value and the dynamic pressure value to compute the pressure value;
- and
- generate a torque command using the pressure value, the torque command being added to a driver assist torque for the steering system.
A power steering system that is configured to:
- determine a rack pressure value based on a driver torque value and a differential pressure across a rack of a steering gear of the power steering system;
- determine a center friction value based on a usage parameter of the power steering system;
- determine a compensation friction value based on a position of a handwheel of the steering system, a vehicle speed, and the center friction value;
- compute a pressure value based on the rack pressure value and the compensation friction value, wherein computing the pressure value further comprises:
- determining a static pressure value based on the rack pressure value, wherein determining the static pressure value comprises multiplying the rack pressure value by a predetermined scaling factor and limiting a result of the multiplication by the compensation friction value;
- determining a dynamic pressure value based on a speed of the handwheel of the steering system;
- and
- adding the static pressure value and the dynamic pressure value to compute the pressure value;
- and
- generate a torque command using the pressure value to compensate for a lash in the steering gear, the torque command being added to a driver assist torque for the power steering system.
Dependencies are inferred from the claim text.