Payload estimation using electric power steering signals
First Claim
1. A payload estimation system of an electric power steering (EPS) system comprising:
- a payload detection module configured to detect payload according to a plurality of EPS signals and generate an axle load factor, the payload detection module comprising;
a rack torque module configured to determine a rack torque acting on a rack connected with the EPS;
a reference model module configured to determine a reference rack torque for the EPS based on a load scale factor; and
a load factor calculation module configured to compute an axle load factor based on a difference between the rack torque and the reference rack torque;
a blend factor module configured to determine a load blend factor according to the axle load factor;
a nominal base assist module configured to determine a nominal base assist based on a handwheel torque signal; and
a highload base assist module configured to generate a highload base assist based on the handwheel torque; and
a signal combiner configured to combine a blended nominal base assist and a blended highload base assist according to the load blend factor, the combination modifying a motor torque command, the motor torque command being sent to a motor to generate assist torque, wherein the blended nominal base assist includes the nominal base assist multiplied by an offset load blend factor, wherein the offset load blend factor comprises 1 minus the load blend factor, and the blended highload base assist comprises the highload base assist multiplied by the load blend factor.
1 Assignment
0 Petitions
Accused Products
Abstract
Technical solutions are described for a payload detection module that detects payload using one or more steering system control signals and generates an axle load factor. An example payload detection module includes a rack torque module to determine a rack torque, a reference model module to determine a reference rack torque for the steering system based on a load scale factor, and a load factor calculation module to compute the axle load factor based on a difference between the rack torque and the reference rack torque. Further, a blend factor module determines a load blend factor according to the axle load factor. Further yet, a signal combiner combines a blended nominal base assist and a blended highload base assist according to the load blend factor, the combination modifying a motor torque command, the motor torque command being sent to a motor to generate assist torque.
-
Citations
18 Claims
-
1. A payload estimation system of an electric power steering (EPS) system comprising:
-
a payload detection module configured to detect payload according to a plurality of EPS signals and generate an axle load factor, the payload detection module comprising; a rack torque module configured to determine a rack torque acting on a rack connected with the EPS; a reference model module configured to determine a reference rack torque for the EPS based on a load scale factor; and a load factor calculation module configured to compute an axle load factor based on a difference between the rack torque and the reference rack torque; a blend factor module configured to determine a load blend factor according to the axle load factor; a nominal base assist module configured to determine a nominal base assist based on a handwheel torque signal; and a highload base assist module configured to generate a highload base assist based on the handwheel torque; and a signal combiner configured to combine a blended nominal base assist and a blended highload base assist according to the load blend factor, the combination modifying a motor torque command, the motor torque command being sent to a motor to generate assist torque, wherein the blended nominal base assist includes the nominal base assist multiplied by an offset load blend factor, wherein the offset load blend factor comprises 1 minus the load blend factor, and the blended highload base assist comprises the highload base assist multiplied by the load blend factor. - View Dependent Claims (2, 3, 4, 5, 6, 7)
-
-
8. A method of estimating a payload for maintaining a substantially consistent steering feel produced at least in-part by an electric power steering (EPS) system, the method comprising:
-
receiving, by a payload detection module of a payload estimation system, a plurality of EPS signals to generate an additional axle load factor; determining, by a reference model module, a reference rack torque for the EPS based on a load scale factor; computing, by a load factor calculation module, an axle load factor based on a difference between the rack torque and the reference rack torque; determining, by a blend factor table of the payload estimation system, a load blend factor according to the additional axle load factor; and modifying, by a merge module, a motor torque command based on the load blend factor, the motor torque command being sent to a motor of the EPS to generate assist torque. - View Dependent Claims (9, 10, 11, 12, 13)
-
-
14. A steering system comprising:
-
a rack torque module configured to determine a rack torque acting on a rack connected with the steering system; a reference model module configured to determine a reference rack torque for the steering system according to a plurality of control signals; a payload detection module configured to compute an axle load factor based on a difference between the rack torque and the reference rack torque; and a signal combiner configured to modify a motor torque command based on the axle load factor, the motor torque command being sent to a motor of the steering system to generate assist torque. - View Dependent Claims (15, 16, 17, 18)
-
Specification