Search

CN-122029089-A - System and method for identifying hand on/off status

CN122029089ACN 122029089 ACN122029089 ACN 122029089ACN-122029089-A

Abstract

A method of identifying a hand on/off condition includes low pass filtering a torsion bar torque signal of an electro-hydraulic power steering system of a vehicle to obtain a filtered torsion bar torque signal (S101), determining a low frequency factor based on the filtered torsion bar torque signal and a steering wheel angular velocity of the vehicle (S102), determining a high frequency factor based on the filtered torsion bar torque signal and the steering wheel angular velocity of the vehicle (S103), determining a characteristic factor based on the high frequency factor and the low frequency factor (S104), and identifying a hand on/off condition based on the characteristic factor (S105). A system for identifying a hand on/off condition is also disclosed.

Inventors

  • CHEN XIAOBO
  • DENG YUAN
  • YANG XI

Assignees

  • 舍弗勒技术股份两合公司

Dates

Publication Date
20260512
Application Date
20240125

Claims (14)

  1. A method of identifying a hand on/off condition, comprising: low-pass filtering a torsion bar torque signal of an electro-hydraulic power steering system of a vehicle to obtain a filtered torsion bar torque signal; determining a low frequency factor based on the filtered torsion bar torque signal and a steering wheel angular velocity of the vehicle; determining a high frequency factor based on the filtered torsion bar torque signal and a steering wheel angular velocity of the vehicle; Determining a characteristic factor based on the high frequency factor and the low frequency factor, and The hand on/off state is identified based on the feature factor.
  2. The method of claim 1, wherein the low pass filtering comprises a series of multi-stage low pass filtering.
  3. The method of claim 1, wherein determining the low frequency factor comprises: the low frequency factor is determined by looking up a table in a preset low frequency map including low frequency factors corresponding to different steering wheel angular velocities in a high frequency region and a low frequency region of the torsion bar torque based on the filtered torsion bar torque signal and the steering wheel angular velocity of the vehicle.
  4. The method of claim 1, wherein determining the high frequency factor comprises: high-pass filtering the filtered torsion bar torque signal to extract a high frequency signal portion; Low-pass filtering the extracted high-frequency signal portion, and The high frequency factor is determined by looking up a table in a preset high frequency map including high frequency factors of a high frequency region and a low frequency region of torsion bar torque corresponding to different steering wheel angular speeds, based on the filtered high frequency signal portion and the steering wheel angular speed of the vehicle.
  5. The method of claim 1, wherein determining the feature factor comprises: superposing the high-frequency factor and the low-frequency factor to obtain a superposed factor; gain processing is carried out on the superimposed factors; accumulating the superimposed factors subjected to gain processing and the characteristic factors at the previous moment; and the accumulated factors are subjected to slope and maximum and minimum limiting processing and then serve as current characteristic factors.
  6. The method of claim 1, wherein identifying a hand-on/off state comprises: low-pass filtering the characteristic factors; adding a bias to the filtered feature factor to control it within a predetermined range; Comparing the filtered characteristic factor with bias to a threshold value, and A hand on/off state is determined based on the result of the comparison.
  7. The system of claim 6, wherein, Determining a hands-off state if the filtered feature factor with the bias added is less than a hands-off threshold; In the event that the filtered feature factor to which the bias is added is greater than or equal to the hands-off threshold, a hand-on condition is determined.
  8. A system for identifying a hand on/off condition, comprising: A torsion bar torque processing module configured to low pass filter a torque signal of a torsion bar of an electro-hydraulic power steering system of a vehicle to obtain a filtered torque signal; A low frequency processing module configured to determine a low frequency factor based on the filtered torque signal and an angular velocity of a steering wheel of the vehicle; a high frequency processing module configured to determine a high frequency factor based on the filtered torque signal and an angular velocity of a steering wheel of the vehicle; A feature processing module configured to determine a feature factor based on the high frequency factor and the low frequency factor, and A state processing module configured to identify a hand on/off state based on the feature factor.
  9. The system of claim 8, wherein the torsion bar torque processing module includes a series of multistage low pass filtering units, wherein the low pass filtering is performed step by the multistage low pass filtering units.
  10. The system of claim 8, wherein the low frequency processing module is configured to: The low frequency factor is determined by looking up a table in a preset low frequency map including low frequency factors corresponding to different steering wheel angular speeds in a high frequency region and a low frequency region of the torsion bar torque based on the filtered torsion bar torque signal and the steering wheel angular speed of the vehicle.
  11. The system of claim 8, wherein the high frequency processing module comprises: a low-pass filtering unit configured to high-pass filter the filtered torsion bar torque signal to extract a high-frequency signal portion; A low-pass filtering unit configured to low-pass filter the extracted high-frequency signal portion, and A high frequency factor determination unit configured to determine a high frequency factor by looking up a table in a preset high frequency map including high frequency factors of a high frequency region and a low frequency region of torsion bar torque corresponding to different steering wheel angular speeds, based on the filtered high frequency signal portion and the steering wheel angular speed of the vehicle.
  12. The system of claim 8, wherein the feature processing module comprises: A superposition unit configured to superimpose the high frequency factor and the low frequency factor to obtain a superimposed factor; a gain unit configured to perform gain processing on the post-superposition factors; an accumulating unit configured to accumulate the gain-processed post-superposition factors with the characteristic factors of the previous time, and And the limiting unit is configured to perform slope and maximum and minimum limiting processing on the accumulated factors to serve as current characteristic factors.
  13. The system of claim 8, wherein the state processing module comprises: a low-pass filtering unit configured to low-pass filter the feature factor; a bias unit configured to add a bias to the filtered feature factor to control it within a predetermined range; A comparison unit configured to compare the filtered characteristic factor with the bias added with a threshold value, and And a state determining unit configured to determine a hand on/off state based on a comparison result of the comparing unit.
  14. The system of claim 13, wherein the hand-on/off state determination unit is configured to: determining a hands-off state if the filtered feature factor with the bias added is less than a hands-off threshold; In the event that the filtered feature factor to which the bias is added is greater than or equal to the hands-off threshold, a hand-on condition is determined.

Description

System and method for identifying hand on/off status Technical Field The present application relates to the field of automotive technology, and more particularly, to a system and method for identifying hand on/off status. Background When the vehicle is equipped with an intelligent driving assistance system/automatic driving system, a hand-off detection function is required in order to prevent the lateral control system from being misused, and a hand-on detection function is required in order to prevent the automatic driving system from being unable to handle and ensure the availability of the driver. Thus, the identification of the hand on/off status is very important for intelligent driving assistance systems/autopilot systems. Disclosure of Invention In one aspect, an embodiment of the present application provides a method of identifying an on/off hand condition comprising low pass filtering a torsion bar torque signal of an electro-hydraulic power steering system of a vehicle to obtain a filtered torsion bar torque signal, determining a low frequency factor based on the filtered torsion bar torque signal and a steering wheel angular velocity of the vehicle, determining a high frequency factor based on the filtered torsion bar torque signal and the steering wheel angular velocity of the vehicle, determining a characteristic factor based on the high frequency factor and the low frequency factor, and identifying the on/off hand condition based on the characteristic factor. In one aspect, an embodiment of the present application provides a system for identifying an on/off hand condition, comprising a torsion bar torque processing module configured to low pass filter a torque signal of a torsion bar of an electro-hydraulic power steering system of a vehicle to obtain a filtered torque signal, a low frequency processing module configured to determine a low frequency factor based on the filtered torque signal and an angular velocity of a steering wheel of the vehicle, a high frequency processing module configured to determine a high frequency factor based on the filtered torque signal and the angular velocity of the steering wheel of the vehicle, a feature processing module configured to determine a feature factor based on the high frequency factor and the low frequency factor, and a state processing module configured to identify an on/off hand condition based on the feature factor. In one aspect, an embodiment of the present application provides a vehicle controller comprising a processor and a memory storing computer readable instructions, wherein the processor is configured to execute the computer readable instructions to implement a method of identifying a hand-on/hand-off condition according to an embodiment of the present application. In one aspect, embodiments of the present application provide a non-transitory computer-readable medium storing instructions that, when executed by one or more processors, cause the one or more processors to implement a method of identifying a hand-on/hand-off state according to embodiments of the present application. Drawings In order to more clearly illustrate the technical solution of the embodiments of the present application, the following briefly describes the drawings to which the embodiments of the present application relate. Other figures may also be obtained from these figures without inventive effort for a person of ordinary skill in the art. In the drawings: FIG. 1 illustrates a flow chart of a method of identifying a hand on/off condition according to an embodiment of the present application; FIG. 2 shows a schematic diagram of torsion bar torque processing according to an embodiment of the present application; FIG. 3 shows a schematic diagram of low frequency processing according to an embodiment of the application; FIG. 4 shows a schematic diagram of high frequency processing according to an embodiment of the application; FIG. 5 shows a schematic diagram of a feature process according to an embodiment of the application; FIG. 6 shows a schematic diagram of state processing according to an embodiment of the application; FIG. 7 is a waveform diagram showing an implementation of a method of identifying a hand on/off state according to an embodiment of the present application; FIG. 8 shows a schematic block diagram of a system for identifying hand on/off status according to an embodiment of the present application; FIG. 9 shows a schematic block diagram of a torsion bar torque processing module in accordance with an embodiment of the present application; Fig. 10 shows a schematic block diagram of a high frequency processing module according to an embodiment of the application; FIG. 11 shows a schematic block diagram of a feature factor processing module according to an embodiment of the application; FIG. 12 shows a schematic block diagram of a state processing module in accordance with an embodiment of the application, and Fig. 13 shows a schematic block diagram o