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EP-4737248-A1 - METHOD OF CONTROLLING A VEHICLE BASED ON ESTIMATION OF POWER DISSIPATION FROM A TIRE, AND COMPUTER SYSTEM

EP4737248A1EP 4737248 A1EP4737248 A1EP 4737248A1EP-4737248-A1

Abstract

A method, comprising: controlling (S41) a vehicle (1) using a first set of control parameters adapted for a first road friction, estimated at a first point in time (t 1 ); receiving (S42) indications of a first temperature (Ti) of a tire (16) a first time derivative of the temperature (Ṫ 1 ) of the tire (16); estimating (S43) a first power dissipation measure (P out,1 ) for the tire (16); receiving (S44) indications of a second temperature (T 2 ) of the tire (16) and a second time derivative of the temperature (Ṫ 2 ) of the tire (16); estimating (S45) a second power dissipation measure (P out,2 ) for the tire (16); detecting (S46) a change in the power dissipation (|P out,2 -P out,1 |) resulting from a change in road surface conditions; and controlling (S48), in response to the detected change (|P out,2 -P out,1 |), the vehicle using a second set of control parameters adapted for a second road friction different from the first road friction.

Inventors

  • ASKERDAL, Mikael
  • Baliga, Nikhil
  • AGARWAL, ROHIT

Assignees

  • Volvo Truck Corporation

Dates

Publication Date
20260506
Application Date
20241030

Claims (15)

  1. A computer system (15) comprising processing circuitry (21) configured to: control a vehicle (1) using a first set of control parameters adapted for a first road friction, estimated at a first point in time (t 1 ); receive, within a predefined first time range (r 1 ) including the first point in time (ti), an indication of a first temperature (T 1 ) of a tire (16) of the vehicle (1) and an indication of a first time derivative of the temperature (T 1 ) of the tire (16); estimate, based on the indication of the first temperature (T 1 ) and the indication of the first time derivative of the temperature (T 1 ), a first power dissipation measure (P out,1 ) indicative of a power dissipation from the tire (16) within the first time range (r 1 ); receive, within a predefined second time range (r 2 ) later than the first time range (r 1 ), an indication of a second temperature (T 2 ) of the tire (16) of the vehicle (1) and an indication of a second time derivative of the temperature (T 2 ) of the tire (16); estimate, based on the indication of the second temperature (T 2 ) and the indication of the second rate of change of the temperature (T 2 ), a second power dissipation measure (P out,2 ) indicative of the power dissipation from the tire (16) within the second time range (r 2 ); detect, based on the first power dissipation measure (P out,1 ) and the second power dissipation measure (P out,2 ), a change (|P out,2 -P out,1 |) in the power dissipation from the tire (16) resulting from a change in road surface conditions having taken place between the first time range (r 1 ) and the second time range (r 2 ); and control, in response to the detected change (|P out,2 -P out,1 |), the vehicle (1) using a second set of control parameters adapted for a second road friction different from the first road friction.
  2. The computer system (15) of claim 1, wherein the processing circuitry (21) is further configured to: determine, based on the detected change (|P out,2 -P out,1 |), that the estimation of the first road friction is no longer valid.
  3. The computer system (15) of claim 2, wherein the processing circuitry (21) is further configured to: assign, in response to the determination that the estimation of the first road friction is no longer valid, the second road friction to a friction being lower than the first road friction.
  4. The computer system (15) of claim 2, wherein the processing circuitry (21) is further configured to: estimate the second road friction based on the first road friction and the detected change (|P out,2 -P out,1 |).
  5. The computer system (15) of any of claims 1-4, wherein the processing circuitry (21) is further configured to: receive, within the first time range (r 1 ),an indication of a first speed (vi) of the vehicle (1); estimate the first power dissipation measure (P out,1 ) additionally based on the indication of the first speed (vi) of the vehicle (1); receive, within the second time range (r 2 ), an indication of a second speed (v 2 ) of the vehicle (1); and estimate the second power dissipation measure (P out,2 ) additionally based on the indication of the second speed (v 2 ) of the vehicle (1).
  6. The computer system (15) of any of claims 1-5, wherein the processing circuitry (21) is further configured to: receive, within the first time range (r 1 ),an indication of a first force (|F 1 |) acting on the tire (16); estimate the first power dissipation measure (P out,1 ) additionally based on the indication of the first force (|F 1 |) acting on the tire (16); receive, within the second time range (r 2 ), an indication of a second force (|F 2 |) acting on the tire (16); and estimate the second power dissipation measure (P out,2 ) additionally based on the indication of the second force (|F 2 |) acting on the tire (16).
  7. The computer system (15) of any of claims 1-6, wherein the processing circuitry (21) is further configured to: receive, within the first time range (r 1 ),an indication of a first road surface temperature (T RS,1 ) and an indication of a first ambient temperature (T a,1 ); estimate the first power dissipation measure (P out,1 ) additionally based on the indication of the first road surface temperature (T RS,1 ) and the indication of the first ambient temperature (T a,1 ); receive, within the second time range (r 2 ), an indication of a second road surface temperature (T RS,2 ) and an indication of a second ambient temperature (T a,2 ); and estimate the second power dissipation measure (P out,2 ) additionally based on the indication of the second road surface temperature (T RS,2 ) and the indication of the second ambient temperature (T a,2 ).
  8. The computer system (15) of any of claims 1-7, wherein the processing circuitry (21) is further configured to: estimate the first power dissipation measure (P out,1 ) as a difference between a first measure indicative of a heat (P in,1 ) generated in the tire (16) and a first measure indicative of a rate of heating (P net,1 ) of the tire (16); and estimate the second power dissipation measure (P out,2 ) as a difference between a second measure indicative of a heat (P in,2 ) generated in the tire (16) and a second measure indicative of a rate of heating (P net,2 ) of the tire (16).
  9. The computer system (15) of any of claims 1-8, wherein the processing circuitry (21) is configured to: receive the indication of the first time derivative of the temperature (T 1 ) of the tire (16) as a first time sequence of temperature values; and receive the indication of the second time derivative of the temperature (T 2 ) of the tire (16) as a second time sequence of temperature values.
  10. The computer system (15) of claim 9, wherein the processing circuitry (21) is configured to: receive the indication of the first temperature (T 1 ) of the tire (16) as one temperature value in the first time sequence of temperature values, or as an average of a plurality of temperature values in the first time sequence of temperature values; and receive the indication of the second temperature (T 2 ) of the tire (16) as one temperature value in the second time sequence of temperature values, or as an average of a plurality of temperature values in the second time sequence of temperature values.
  11. The computer system (15) of any of claims 1-10, wherein the first time range is less than 15 minutes.
  12. A vehicle (1) comprising at least one vehicle wheel (11) with a tire (16), at least one temperature sensor (17) arranged to measure a temperature of the tire (16), and the computer system of any of claims 1-11.
  13. A computer-implemented method, comprising: controlling (S41) a vehicle (1) using a first set of control parameters adapted for a first road friction, estimated at a first point in time (t 1 ); receiving (S42), within a predefined first time range (r 1 ) including the first point in time (t 1 ), an indication of a first temperature (T 1 ) of a tire (16) of the vehicle (1) and an indication of a first time derivative of the temperature (T 1 ) of the tire (16); estimating (S43), based on the indication of the first temperature (T 1 ) and the indication of the first time derivative of the temperature (T 1 ), a first power dissipation measure (P out,1 ) indicative of a power dissipation from the tire (16) within the first time range (r 1 ); receiving (S44), within a predefined second time range (r 2 ) later than the first time range (r 1 ),an indication of a second temperature (T 2 ) of the tire (16) of the vehicle (1) and an indication of a second time derivative of the temperature (T 2 ) of the tire (16); estimating (S45), based on the indication of the second temperature (T 2 ) and the indication of the second rate of change of the temperature (T 2 ), a second power dissipation measure (P out,2 ) indicative of the power dissipation from the tire (16) within the second time range (r 2 ); detecting (S46), based on the first power dissipation measure (P out,1 ) and the second power dissipation measure (P out,2 ), a change in the power dissipation (|P out,2- P out,1 |) from the tire (16) resulting from a change in road surface conditions having taken place between the first time range (r 1 ) and the second time range (r 2 ); and controlling (S48), in response to the detected change (|P out,2 -P out,1 |), the vehicle (1) using a second set of control parameters adapted for a second road friction different from the first road friction.
  14. The method of claim 13, comprising: determining, based on the detected change (|P out,2 -P out,1 |), that the first friction is no longer valid.
  15. A computer program product comprising program code for performing, when executed by the processing circuitry (21) comprised in the computer system (15) of any one of claims 1-11, the method of claim 13-14.

Description

TECHNICAL FIELD The disclosure relates generally to evaluation of a road friction estimation. In particular aspects, the disclosure relates to a method of controlling a vehicle based on estimations of power dissipation from a tire, and to a computer system. The disclosure can be applied to heavy-duty vehicles, such as trucks, buses, and construction equipment, among other vehicle types. Although the disclosure may be described with respect to a particular vehicle, the disclosure is not restricted to any particular vehicle. BACKGROUND Methods exist for estimating an instantaneous road friction. However, road conditions may change, and there may be times when such methods cannot be used, for various reasons. It would be desirable to enable evaluation of the validity of a previously estimated instantaneous road friction. SUMMARY According to a first aspect of the disclosure, there is provided a computer system comprising processing circuitry configured to: control a vehicle using a first set of control parameters adapted for a first road friction, estimated at a first point in time; receive, within a predefined first time range including the first point in time, an indication of a first temperature of a tire of the vehicle and an indication of a first time derivative of the temperature of the tire; estimate, based on the indication of the first temperature and the indication of the first time derivative of the temperature, a first power dissipation measure indicative of a power dissipation from the tire within the first time range; receive, within a predefined second time range later than the first time range, an indication of a second temperature of the tire of the vehicle and an indication of a second time derivative of the temperature of the tire; estimate, based on the indication of the second temperature and the indication of the second rate of change of the temperature, a second power dissipation measure indicative of the power dissipation from the tire within the second time range; detect, based on the first power dissipation measure and the second power dissipation measure, a change in the power dissipation from the tire resulting from a change in road surface conditions having taken place between the first time range and the second time range; and control, in response to the detected change, the vehicle using a second set of control parameters adapted for a second road friction different from the first road friction. The first aspect of the disclosure may seek to enable evaluation of the validity of a previously estimated instantaneous road friction. This may, in turn, provide for improved control of the vehicle. A technical benefit may include to enable detection of a change in road surface conditions that may render a previously estimated road friction to no longer be valid. Based on such a finding, the control parameters used for controlling operation of the vehicle may be changed. Conversely, it may be beneficial to be able to conclude that the previously estimated instantaneous road friction is still valid, so that the set of control parameters adapted for that road friction may continue to be used. This may allow for continued operation of the vehicle using road friction optimized control parameters for a longer time when the change in the power dissipation from the tire that may result from a change in road surface conditions is determined to be sufficiently small. This may, in turn, provide for vehicle control resulting in improved fuel efficiency and/or reduced particle emissions, as compared to the situations where control parameters adapted for a conservative estimate of the road friction are used. A conservative estimate may be a low road friction, such a lower than the previously estimated first road friction. The indication of the first temperature of the tire at a time within the first time range and the indication of the second temperature of the tire at a time within the second time range may be indicative of instantaneous temperatures of the vehicle tire. The instantaneous temperatures of the vehicle tire may, for example, be the rubber temperatures measured from an inside of the tire, or temperatures of the gas (typically air) enclosed by the tire, or temperatures of a thread surface on the outside of the tire, or temperatures of a shoulder of the tire, or a combination of one or more of these temperatures. In the context of the present application, "the first time derivative" should be understood to mean the time derivative at a first point in time, and "the second time derivative" should be understood to mean the time derivative at a second point in time. In particular, the expression "the second time derivative" should not be interpreted as having been differentiated twice in respect of time. A power dissipation from the tire within a time range may be the power dissipation from the tire at a point in time within the time range, or an average power dissipation from the tire for t