US-12617386-B2 - Control system for controlling a retardation of a vehicle

Abstract

A control system for controlling a retardation of a vehicle. The control system is adapted to use power loss information for each motion support device controlling the retardation of the vehicle. For each one of the motion support devices, the power loss information is such that, for each one of a plurality of operating points, the power loss information comprises a power loss value indicative of a power loss of the motion support device when operated at the operating point, each operating point being related to at least a load produced by the motion support device.

Inventors

• José Vilca
• Esteban GELSO
• Leo Laine
• Mikael ASKERDAL
• Mats Jonasson
• Sachin JANARDHANAN

Assignees

• VOLVO TRUCK CORPORATION

Dates

Publication Date

20260505

Application Date

20220317

Claims (16)

1. 1 . A control system for controlling a retardation of a vehicle; the vehicle comprising a set of motion support devices for controlling the retardation of the vehicle, at least a first motion support device in the set of motion support devices being an electric motor and at least a second motion support device in the set of motion support devices being a service brake, the vehicle comprising a set of wheels whereby each motion support device in the set of motion support devices being drivingly connected, directly or indirectly, to one or more of the wheels; the control system being adapted to use power loss information for each motion support device in the set of motion support devices; wherein, for each one of the motion support devices, the power loss information is such that, for each one of a plurality of operating points, the power loss information comprises a power loss value indicative of a power loss of the motion support device when operated at the operating point, each operating point being related to at least a load produced by the motion support device; the control system being adapted to: receive a vehicle retardation request indicative of a requested retardation of the vehicle; use the power loss information for each motion support device in the set of motion support devices in order to determine a brake load to be supplied by each motion support device in the set of motion support devices such that the aggregated brake load supplied by the set of motion support devices results in a retardation of the vehicle corresponding to the vehicle retardation request; and issue information to the set of motion support devices indicative of the brake load to be supplied by each motion support device in the set of set of motion support devices.
2. 2 . The control system of claim 1 , wherein the control system is adapted to use the power loss information for each motion support device in the set of motion support devices in order to determine a brake load to be supplied by each motion support device in the set of motion support devices such that the aggregated brake load supplied by the set of motion support devices results in a retardation of the vehicle corresponding to the vehicle retardation request and such that the aggregated power loss from the set of motion support devices is equal to or lower than an aggregated power loss threshold associated with the vehicle retardation request.
3. 3 . The control system of claim 1 , wherein the control system is adapted to use the power loss information for each motion support device in the set of motion support devices in order to determine a brake load to be supplied by each motion support device in the set of motion support devices such that the aggregated brake load supplied by the set of motion support devices results in a retardation of the vehicle corresponding to the vehicle retardation request and such that an absolute value of the difference between the aggregated power loss from the set of motion support devices and a minimum value of the aggregated power losses associated with the vehicle retardation request is equal to or below a predetermined difference threshold.
4. 4 . The control system of claim 1 , wherein the control system comprises a memory adapted to store the power loss information for each motion support device in the set of motion support devices.
5. 5 . The control system of claim 1 , wherein for the power loss information for at least one, of the motion support devices in the set of motion support devices, each operating point is related to at least a load produced by the motion support device as well as information indicative of a rotational speed of a wheel connected to the motion support device.
6. 6 . The control system of claim 1 , wherein the first motion support device in the set of motion support devices is an electric motor connected to an energy storage device and for the power loss information for the first motion support device, each operating point is related to at least a load produced by the motion support device as well as information indicative of current state of charge associated with the energy storage device and/or a current maximum charging rate associated with the energy storage device.
7. 7 . The control system of claim 1 , wherein, for each one of the motion support devices, each operating point is related to at least a load produced by the motion support device as well as information indicative of a current temperature of at least a portion of the motion support device.
8. 8 . The control system of claim 1 , wherein the load produced by each motion support device is one of the following: a force and a torque.
9. 9 . A vehicle comprising a set of motion support devices for controlling the retardation of the vehicle, at least a first motion support device in the set of motion support devices being an electric motor and at least a second motion support device in the set of motion support devices being a service brake, the vehicle comprising a set of wheels whereby each motion support device in the set of motion support devices being drivingly connected, directly or indirectly, to one or more of the wheels, the vehicle comprising the control system of claim 1 .
10. 10 . A method for controlling a retardation of a vehicle: the vehicle comprising a set of motion support devices for controlling the retardation of the vehicle, at least a first motion support device in the set of motion support devices being an electric motor and at least a second motion support device in the set of motion support devices being a service brake, the vehicle comprising a set of wheels whereby each motion support device in the set of motion support devices being drivingly connected, directly or indirectly, to one or more of the wheels; the method comprising using power loss information for each motion support device in the set of motion support devices; wherein, for each one of the motion support devices, the power loss information is such that, for each one of a plurality of operating points, the power loss information comprises a power loss value indicative of a power loss of the motion support device when operated at the operating point, each operating point being related to at least a load produced by the motion support device; the method comprising: receiving a vehicle retardation request indicative of a requested retardation of the vehicle; using the power loss information for each motion support device in the set of motion support devices in order to determine a brake load to be supplied by each motion support device in the set of motion support devices such that the aggregated brake load supplied by the set of motion support devices results in a retardation of the vehicle corresponding to the vehicle retardation request; and issuing information to the set of motion support devices indicative of the brake load to be supplied by each motion support device in the set of set of motion support devices.
11. 11 . The method of claim 10 , wherein the method comprises using the power loss information for each motion support device in the set of motion support devices in order to determine a brake load to be supplied by each motion support device in the set of motion support devices such that the aggregated brake load supplied by the set of motion support devices results in a retardation of the vehicle corresponding to the vehicle retardation request and such that the aggregated power loss from the set of motion support devices is equal to or lower than an aggregated power loss threshold associated with the vehicle retardation request.
12. 12 . The method of claim 10 , wherein the method comprises using the power loss information for each motion support device in the set of motion support devices in order to determine a brake load to be supplied by each motion support device in the set of motion support devices such that the aggregated brake load supplied by the set of motion support devices results in a retardation of the vehicle corresponding to the vehicle retardation request and such that an absolute value of the difference between the aggregated power loss from the set of motion support devices and a minimum value the aggregated power losses associated with the vehicle retardation request is equal to or below a predetermined difference threshold.
13. 13 . The method of claim 10 , wherein for the power loss information for at least one of the motion support devices in the set of motion support devices, each operating point is related to at least a load produced by the motion support device as well as information indicative of a rotational speed of a wheel connected to the motion support device.
14. 14 . The method of claim 10 , wherein the first motion support device in the set of motion support devices is an electric motor connected to an energy storage device and for the power loss information for the first motion support device, each operating point is related to at least a load produced by the motion support device as well as information indicative of current state of charge associated with the energy storage device and/or a current maximum charging rate associated with the energy storage device.
15. 15 . The method of claim 10 , wherein, for each one of the motion support devices, each operating point is related to at least a load produced by the motion support device as well as information indicative of a current temperature of at least a portion of the motion support device.
16. 16 . The method of claim 10 , wherein the load produced by each motion support device is one of the following: a force and a torque.

Description

This application is a 35 USC 371 national phase filing of International Application No. PCT/EP2022/057050, filed Mar. 17, 2022, the disclosure of which is incorporated herein by reference in its entirety. TECHNICAL FIELD The invention relates to a control system for controlling a retardation of a vehicle. Moreover, the present invention relates to a vehicle. Additionally, the present invention relates to a method for controlling a retardation of a vehicle. The invention can be applied in heavy-duty vehicles, such as trucks, buses and construction equipment. Although the invention will be described with respect to a truck, the invention is not restricted to this particular vehicle, but may also be used in other vehicles such as busses, haulers and other types of vehicles. BACKGROUND A contemporary vehicle may comprise a plurality of motion support devices for controlling the propulsion of the vehicle. At least one of the motion support devices may be an electric motor and another motion support device may be a service brake. The motion support devices may be controlled in order to arrive at a desired state of the vehicle, such as a desired positive acceleration or a negative acceleration. Such a negative acceleration may also be referred to as a retardation. For instance, according to its abstract, US2005/0130796 A1 discloses a method for controlling a hybrid drive of a vehicle. The hybrid drive includes as propulsion motors an internal combustion engine and at least one electric motor/generator, and the output shafts of the propulsion motors being operatively linkable to a power train of the vehicle. The propulsion motors and an electrically activatable braking system of the vehicle are activated in a coordinated manner as a function of a negative load request, taking this negative load request into account. However, there is still a need for further improvements as regards the control of a vehicle, for instance when retarding a vehicle. SUMMARY An object of the invention is to provide a control system by which a vehicle can be retarded in an energy efficient manner. According to a first aspect of the invention, the object is achieved by a control system according to claim 1. As such, the present invention relates to a control system for controlling a retardation of a vehicle. The vehicle comprises a set of motion support devices for controlling the retardation of the vehicle. At least a first motion support device in the set of motion support devices is an electric motor and at least a second motion support device in the set of motion support devices is a service brake. The vehicle comprises a set of wheels whereby each motion support device in the set of motion support devices is drivingly connected, directly or indirectly, to one or more of the wheels. The control system is adapted to use power loss information for each motion support device in the set of motion support devices. For each one of the motion support devices, the power loss information is such that, for each one of a plurality of operating points, the power loss information comprises a power loss value indicative of a power loss of the motion support device when operated at the operating point, each operating point being related to at least a load produced by the motion support device. According to the invention, the control system is adapted to: receive a vehicle retardation request indicative of a requested retardation of the vehicle;use the power loss information for each motion support device in the set of motion support devices in order to determine a brake load to be supplied by each motion support device in the set of motion support devices such that the aggregated brake load supplied by the set of motion support devices results in a retardation of the vehicle corresponding to the vehicle retardation request, andissue information to the set of motion support devices indicative of the brake load to be supplied by each motion support device in the set of set of motion support devices. As such, the control system of the present invention uses power loss information for each motion support device, including the at least one motion support device being a service brake, when determining the brake load to be supplied by each motion support device. This in turns implies that the set of motion support devices may be controlled such that an appropriately low total power loss may be arrived at when retarding a vehicle. To this end, the inventors of the present invention have realized that using also the power loss information for the second motion support device being a service brake when determining a brake load to be supplied by each motion support device in the set of motion support devices may result in that load distributions amongst the motion support devices may be arrived at which may result in lower total power losses as compared to control units employing a control strategy in which e.g. only the power losses amongst the electric motor