SE541911C2

SE541911C2 - Method and a control device for controlling parking brakes of a vehicle in connection to a suspension level change

Info

Publication number: SE541911C2
Application number: SE1850627A
Authority: SE
Inventors: Henrik Svensson; Johan Hesse; Robert Skaba; Stefan Sappei
Original assignee: Scania Cv Ab
Priority date: 2018-05-25
Filing date: 2018-05-25
Publication date: 2020-01-07
Also published as: SE1850627A1

Abstract

The present invention relates to a method (M1) performed by a control device (100) for controlling parking brakes of a vehicle (V1) in connection to level change of the vehicle (V1). The vehicle (V1) comprises a vehicle level adjustment system having bellows (B1 , B2, B3, B4) arranged in connection to wheel axles (X1 , X2) of the vehicle (V1 ). The control device (100) comprises a function for reducing the braking force for those wheels of one or more wheel axles where level change may induce chassis stresses. The method comprises determining whether reducing the braking force for those wheels of one or more wheel axles where level change may induce chassis stresses may cause the vehicle (V1) to move. If it is determined that thus reducing the braking force may cause the vehicle (V1) to move action is taken so as to prevent such movement; and, if not, the braking force is thus reduced.The present invention also relates to a control device for controlling parking brakes of a vehicle in connection to level change of the vehicle. The present invention also relates to a vehicle. The present invention also relates to a computer program and a computer readable medium.

Description

METHOD AND A CONTROL DEVICE FOR CONTROLLING PARKING BRAKES OF A VEHICLE IN CONNECTION TO A SUSPENSION LEVEL CHANGE TECHNICAL FIELD The invention relates to a method performed by a control device for controlling parking brakes of a vehicle in connection to level change of the vehicle. The invention also relates to a control device for controlling parking brakes of a vehicle in connection to level change of the vehicle. The invention further relates to a vehicle. The invention in addition relates to a computer program and a computer readable medium.

BACKGROUND ART Certain vehicles such as heavy vehicles in the shape of trucks are equipped with vehicle level adjustment systems having bellows arranged in connection to wheel axles of the vehicle. Such vehicle level adjustment systems are usually comprised in the suspension system of the vehicle.

Such bellows are configured to provide level change of the chassis of the vehicle relative to the wheel axle level which may be desired for certain vehicle operations. During such vehicle operations involving level change of the chassis of the vehicle, parking brake of the vehicle are engaged for providing a braking force for the wheels of the wheel axles. Such level change may however induce chassis stresses on the chassis of the vehicle. In order to avoid such chassis stresses the parking brake is disengaged in connection to the level change.

There is however a need to improve control of parking brakes of a vehicle in connection to level change of the vehicle.

OBJECTS OF THE INVENTION An object of the present invention is to provide a method performed by a control device for controlling parking brakes of a vehicle in connection to level change of the vehicle which facilitates improving safety.

Another object of the present invention is to provide a control device for controlling parking brakes of a vehicle in connection to level change of the vehicle which facilitates improving safety.

Another object of the present invention is to provide a vehicle comprising such a control device.

SUMMARY OF THE INVENTION These and other objects, apparent from the following description, are achieved by a method, a control device, a vehicle, a computer program and a computer readable medium, as set out in the appended independent claims. Preferred embodiments of the method and the control device are defined in appended dependent claims.

Specifically an object of the invention is achieved by a method performed by a control device for controlling parking brakes of a vehicle in connection to level change of the vehicle. The vehicle comprises a vehicle level adjustment system having bellows arranged in connection to wheel axles of the vehicle. The bellows are configured to provide level change of the chassis of the vehicle relative to the wheel axle level. Parking brakes are arranged for providing braking force for the wheels of the wheel axles. The control device comprises a function for reducing the braking force for those wheels of one or more wheel axles where level change may induce chassis stresses. The method comprises the steps of: determining whether reducing the braking force for those wheels of one or more wheel axles where level change may induce chassis stresses may cause the vehicle to move; if it is determined that thus reducing the braking force may cause the vehicle to move, taking action so as to prevent such movement; and, if it is determined that thus reducing the braking force may not cause the vehicle to move, reducing the braking force. By thus preventing movement of the vehicle safety may be improved.

According to an embodiment of the method the step of determining whether reducing the braking force for those wheels of one or more wheel axles where level change may induce chassis stresses may cause the vehicle to move comprises determining inclination of the surface on which the vehicle is parked. By thus determining the inclination of the surface on which the vehicle is parked, information for facilitating determining whether such level change may cause the vehicle to move.

According to an embodiment of the method the step of determining whether reducing the braking force for those wheels of one or more wheel axles where level change may induce chassis stresses may cause the vehicle to move comprises determining one or more of the parameters: load of the vehicle; frictional circumstances for the vehicle; weather conditions; tire conditions of the vehicle wheels. Hereby determination of whether such level change may cause the vehicle to move is further improved.

According to an embodiment of the method the step of taking action so as to prevent such movement of the vehicle comprises the step of preventing reducing the braking force for those wheels of one or more wheel axles where level change may induce chassis stresses which may cause the vehicle to move. Hereby efficient prevention of movement is obtained.

According to an embodiment of the method the step of taking action so as to prevent such movement of the vehicle comprises determining whether the vehicle operator is in the driver position for braking the vehicle. Hereby efficient prevention of movement is obtained, wherein, if the vehicle operator is in the driver position for braking the vehicle, the parking brake force may be reduced due to the fact the operator may brake the vehicle, and, if not, prevention of the reducing the braking force for those wheels of one or more wheel axles where level change may induce chassis stresses which may cause the vehicle to move may be performed.

Specifically an object of the invention is achieved by a control device for controlling parking brakes of a vehicle in connection to level change of the vehicle. The vehicle comprises a vehicle level adjustment system having bellows arranged in connection to wheel axles of the vehicle. The bellows are configured to provide level change of the chassis of the vehicle relative to the wheel axle level. Parking brakes are arranged for providing braking force for the wheels of the wheel axles. The control device comprises a function for reducing the braking force for those wheels of one or more wheel axles where level change may induce chassis stresses. The control device is configured to: determine whether reducing the braking force for those wheels of one or more wheel axles where level change may induce chassis stresses may cause the vehicle to move; if it is determined that thus reducing the braking force may cause the vehicle to move, take action so as to prevent such movement; and, if it is determined that thus reducing the braking force may not cause the vehicle to move, reduce the braking force.

According to an embodiment the control device, when determining whether reducing the braking force for those wheels of one or more wheel axles where level change may induce chassis stresses may cause the vehicle to move, is configured to determine inclination of the surface on which the vehicle is parked.

According to an embodiment the control device, when determining whether reducing the braking force for those wheels of one or more wheel axles where level change may induce chassis stresses may cause the vehicle to move, is configured to determine one or more of the parameters: load of the vehicle; frictional circumstances for the vehicle; weather conditions; tire conditions of the vehicle wheels.

According to an embodiment the control device, when taking action so as to prevent such movement of the vehicle, is configured to prevent reduction of the braking force for those wheels of one or more wheel axles where level change may induce chassis stresses which may cause the vehicle to move.

According to an embodiment the control device, when taking so as to prevent such movement of the vehicle, is configured to determine whether the vehicle operator is in the driver position for braking the vehicle.

Specifically an object of the invention is achieved by a vehicle comprising a control device as set out herein.

Specifically an object of the invention is achieved by a computer program for controlling parking brakes of a vehicle in connection to level change of the vehicle, said computer program comprising program code which, when run on an control device or another computer connected to the control device, causes the control device to perform the method steps as set out herein.

Specifically an object of the invention is achieved by a computer readable medium comprising instructions which, when executed by a computer, cause the computer to carry out the method as set out herein.

BRIEF DESCRIPTION OF THE DRAWINGS For a better understanding of the present invention reference is made to the following detailed description when read in conjunction with the accompanying drawings, wherein like reference characters refer to like parts throughout the several views, and in which: Fig. 1 schematically illustrates a side view of a vehicle according to an embodiment of the present disclosure; Fig. 2 is a schematic plan view of a vehicle in fig. 1 showing its chassis and vehicle level adjustment system; Fig. 3 schematically illustrates a block diagram of a control device for controlling parking brakes of a vehicle in connection to level change of the vehicle according to an embodiment of the present disclosure; Fig. 4 schematically illustrates a flowchart of a method performed by a control device for controlling parking brakes of a vehicle in connection to level change of the vehicle according to an embodiment of the present disclosure; and Fig. 5 schematically illustrates a computer according to an embodiment of the present disclosure.

DETAILED DESCRIPTION Hereinafter the term “link” refers to a communication link which may be a physical connector, such as an optoelectronic communication wire, or a nonphysical connector such as a wireless connection, for example a radio or microwave link.

Fig. 1 schematically illustrates a side view of a vehicle V1 according to an embodiment of the present disclosure.

The exemplified vehicle V1 is a heavy vehicle in the shape of a truck. The vehicle comprises a vehicle body 1a, 1b comprising a cab 1a and a chassis 1b. The vehicle V1 is parked on a ground G. The ground G, i.e. the surface of the ground G, has a certain inclination a.

The vehicle V1 comprises a front axle X1 with front wheels LF and a powered rear axle X2 with tractive wheels LD. The vehicle V1 is further provided with a vehicle level adjustment system comprising a set of level adjustment bellows of which a second bellows unit B2 arranged in connection to the front axle X1 and fourth bellows unit B4 arranged in connection to the rear axle X2 are shown in fig. 1. The vehicle comprises a parking brake system comprising parking brakes for providing braking force for the wheels LF, LD of the wheel axles X1 , X2.

The bellows unit B4 arranged in connection to the rear axle X2 is arranged a certain distance from the rear axle X2 so that, if parking brakes are activated to provide a braking force for the wheels LD of the rear axle X2, chassis stresses may be induced in the chassis of the vehicle. The level adjustment bellows B4 in connection to the rear axle X2 has provided a level change of the chassis of the vehicle relative to the level of the rear axle X2, here a level increase, and thus the chassis 1b of the vehicle is at a raised level at a distance D from the ground G.

The control device 100 is configured to determine whether reducing the braking force for those wheels of one or more wheel axles, i.e. here the wheels LD of the rear axle X2, where level change may induce chassis stresses may cause the vehicle to move. Here the inclination a may cause the vehicle V1 to move if the braking force of the parking brakes is reduced. If it is determined that thus reducing the braking force may cause the vehicle V1 to move, action is taken so as to prevent such movement. Such action may involve preventing reduction of the braking force of the parking brakes.

The vehicle V1 may comprise a control device for controlling parking brakes of a vehicle in connection to level change of the vehicle. The vehicle V1 may comprise or be operably connectable to a system I for controlling parking brakes of a vehicle in connection to level change of the vehicle. The system I may comprise a control device 100 for controlling parking brakes of a vehicle in connection to level change of the vehicle.

The control device 100 comprises a function for reducing the braking force for those wheels of one or more wheel axles where level change may induce chassis stresses.

The vehicle V1 comprises, according to an embodiment, a control device 100 for controlling parking brakes of the vehicle V1 in connection to level change of the vehicle according to fig. 3.

The vehicle V1 is, according to an embodiment, arranged to be operated in accordance with a method M1 for controlling parking brakes of a vehicle in connection to level change of the vehicle according to fig. 4.

Fig. 2 is a schematic plan view of the vehicle V1 in fig. 1 showing its chassis and vehicle level adjustment system. The vehicle V1 comprises a frame 2, 3, a front axle X1 with opposite front wheels RF, LF and a powered rear axle X2, i.e. drive axle X2, with opposite tractive wheels RD, LD. The vehicle is further provided with a vehicle level adjustment system comprising a set of level adjustment bellows. The set of level adjustment bellows comprises a first bellows unit B1 situated on the right side in connection to the front axle X1 and a second bellows unit B2 situated on the left side in connection to the front axle X1. The set of level adjustment bellows further comprises a third bellows unit B3 situated on the right side in connection to the powered rear axle X2 and a fourth bellows unit B4 situated on the left side in connection to the powered rear axle X2. The third bellows unit B3 and the fourth bellow unit B4 are arranged a certain distance from the rear axle X2. Chassis stresses may be induced in the chassis of the vehicle when level change is provided if the parking brakes are providing a braking force for the wheels RD, LD of the rear axle X2.

The respective bellows units B1-B4 are situated between the vehicle frame 2, 3 and the respective axles X1 , X2, making it possible for the vehicle body of the vehicle to be raised and lowered by regulation of air in bellows units.

The vehicle level adjustment system further comprises an air valve configuration A according to an embodiment of the present disclosure. The air valve configuration is connected to the set of level adjustment bellows B1, B2, B3, B4 and is adapted to regulating the air pressure in the respective bellows units B1, B2, B3, B4 of the set of level adjustment bellows.

The vehicle further comprises an air pressure source configuration A1 for supplying air to the air valve configuration 100.

The air valve configuration A comprises in one embodiment air valve units comprising valve means with an air intake connected to a compressed air source, a venting outlet and a supply outlet, and valve means adapted to regulating the air pressure in the bellows units.

The vehicle comprises a parking brake system comprising parking brakes P1, P2, P3, P4 arranged for providing braking force for the wheels of the wheel axles. The parking brake system comprising parking brakes P1, P2, P3, P4 comprises a first parking brake P1 arranged to provide braking force for the right front wheel RF, a second parking brake P2 arranged to provide braking force for the left front wheel LF, a third parking brake P3 arranged to provide braking force for the right drive wheel RD and a fourth parking brake P4 arranged to provide braking force for the left drive wheel LD.

As mentioned above with reference to fig. 1, the vehicle V1 may comprise a control device 100 for controlling the parking brakes P1, P2, P3, P4 of the vehicle V1 in connection to level change of the vehicle V1. The control device 100 is according to this embodiment operably connectable to the parking brake system, i.e. operably connectable to the parking brakes P1, P2, P3, P4, via links. The control device 100 comprises a function for reducing the braking force for those wheels of one or more wheel axles where level change may induce chassis stresses.

The air valve configuration A may be connected to an electronic control unit 200 which is adapted to causing the air valve configuration to regulate bellows units B1, B2, B3, B4 for raising and lowering of the vehicle body of the vehicle so as to adjust the level of the vehicle.

The vehicle level adjustment system may comprise level sensors for determining the level of the vehicle body/chassis/frame relative to a reference, e.g. the axles X1, X2 and/or ground and/or wheels RF, LF, RD, LD. The electronic control unit 200 may be operably connected to the level sensors via links, and may receive data representing level of the vehicle chassis relative to the vehicle axles X1, X2 and data representing level change.

The control device 100 may be operably connected to the electronic control unit 200. The control device 100 may receive data representing level of the vehicle chassis relative to the vehicle axles X1, X2 and data representing level change.

The control device 100 is configured to determine whether reducing the braking force for those wheels of one or more wheel axles where level change may induce chassis stresses may cause the vehicle to move. When determining whether reducing the braking force for those wheels of one or more wheel axles where level change may induce chassis stresses may cause the vehicle to move, the control device 100 is configured to determine inclination of the surface on which the vehicle is parked. The control device 100 may be configured to receive data about inclination of the surface on which the vehicle is parked. When determining whether reducing the braking force for those wheels of one or more wheel axles where level change may induce chassis stresses may cause the vehicle to move, the control device may further be configured to determine one or more of the parameters: load of the vehicle; frictional circumstances for the vehicle; weather conditions; tire conditions of the vehicle wheels. The control device 100 may be configured to receive data about load of the vehicle; frictional circumstances for the vehicle; weather conditions; and/or tire conditions of the vehicle wheels. Below, with reference to fig. 3, a control device 100 for controlling parking brakes of a vehicle in connection to level change of the vehicle is described where The vehicle V1 described above with reference to fig. 1 and fig. 2 has a front axle X1 and a drive axle X2. The invention is however applicable to any suitable vehicle. The vehicle according to the present invention may be any suitable vehicle having a vehicle level adjustment system having bellows arranged in connection to wheel axles of the vehicle, where the bellows are configured to provide level change of the chassis of the vehicle relative to the wheel axle level, such as a truck, a bus or a car. The vehicle according to the present invention may have any suitable number of wheel axles with wheels. One or more of the wheel axles with wheels may be drive axle for propelling the wheels of the vehicle. The vehicle according to the present invention may have one or more front axles, one or more rear axles operating as drive axles in combination with non-driving support axles arranged in front and/or behind driving axel/axles. The vehicle according to the present invention may have one or more axles with steerable wheels. The vehicle according to the present invention may have any suitable parking brake system comprising parking brakes arranged for providing braking force for the wheels of the wheel axles of at least one of the wheel axles. Thus, a parking brake system of a vehicle may have any suitable parking brake configuration. Thus, different vehicles may have different number of axles being provided with parking brakes arranged for providing braking force for the wheels of those axles. Thus, different vehicles may have different number of parking brake axles, i.e. axles being configured to be provided with parking brake force by means of parking brakes.

The level adjustment systems comprising bellows B1, B2, B3, B4 are according to an embodiment comprised in an air suspension system of the vehicle.

Fig. 3 schematically illustrates a block diagram of a control device 100 for controlling parking brakes of a vehicle in connection to level change of the vehicle according to an embodiment of the present disclosure.

The control device 100 is configured to control parking brakes of a vehicle. The control device 100 is configured to control parking brakes of a vehicle in connection to level change of the vehicle.

The control device 100 for controlling parking brakes of a vehicle in connection to level change of the vehicle may be comprised in a system I for controlling parking brakes of a vehicle in connection to level change of the vehicle.

The control device 100 may be implemented as a separate entity or distributed in two or more physical entities. The control device 100 may comprise one or more computers. The control device may thus be implemented or realised by the control device comprising a processor and a memory, the memory comprising instructions, which when executed by the processor causes the control device to perform the herein disclosed method.

The control device 100 may comprise one or more electronic control units, processing units, computers, server units or the like for determining vehicle operation of at least one vehicle. The control device 100 may comprise control device such as one or more electronic control units arranged on board a vehicle. The control device 100 may comprise one or more electronic control units of the vehicle. The control device 100 may comprise one or more electronic control units, processing units, computers, server units or the like of an off-board system arranged externally to the vehicle and being operably connectable to the vehicle.

The vehicle comprises a vehicle level adjustment system having bellows arranged in connection to wheel axles of the vehicle. The bellows are configured to provide level change of the chassis of the vehicle relative to the wheel axle level. Parking brakes are arranged for providing braking force for the wheels of the wheel axles.

The control device 100 comprises a function for reducing the braking force for those wheels of one or more wheel axles where level change may induce chassis stresses. The control device 100 is configured to reduce the braking force for those wheels of one or more wheel axles where level change may induce chassis stresses by means of the function for reducing the braking force. Reducing the braking force may comprise releasing the braking force so that there is no such braking force.

The control device 100 comprises or is configured to receive information about parking brake configuration of the parking brake system of the vehicle.

The control device 100 is configured to determine whether reducing the braking force for those wheels of one or more wheel axles where level change may induce chassis stresses may cause the vehicle to move.

The system I may comprise vehicle movement determination arrangement 110 arranged to determine whether reducing the braking force for those wheels of one or more wheel axles where level change may induce chassis stresses may cause the vehicle to move.

The control device 100 may comprise or be operably connectable to the vehicle movement determination arrangement 110.

According to an embodiment the control device 100, when determining whether reducing the braking force for those wheels of one or more wheel axles where level change may induce chassis stresses may cause the vehicle to move, is configured to determine inclination of the surface on which the vehicle is parked. The control device 100 is configured to determine inclination of the surface on which the vehicle is parked.

According to an embodiment the vehicle movement determination arrangement 110 comprises a surface inclination determination device 112. The surface inclination determination device 112 may comprise one or more inclination detectors. Such inclination detectors may be any suitable inclination detector such as an inclinometer, tilt sensor, gyro or the like.

According to an embodiment the control device 100, when determining whether reducing the braking force for those wheels of one or more wheel axles where level change may induce chassis stresses may cause the vehicle to move, is configured to determine load of the vehicle.

According to an embodiment the vehicle movement determination arrangement 110 comprises vehicle load determination device 114.

The system I may comprise the vehicle load determination device 114. The vehicle load determination device 114 may be arranged to determine the total load of the vehicle. The vehicle load determination device 114 may be arranged to determine the axle load of the respective axle of the vehicle. The vehicle load determination device 114 may thus be arranged to determine the weight distribution of the vehicle axles.

The control device 100 may comprise or be operably connectable to the vehicle load determination device 114.

The vehicle load determination device 114 may comprise one or more vehicle load detection sensors for detecting vehicle load.

The one or more vehicle load detection sensors may comprise one or more load detection sensors arranged in connection to the wheel axles of the vehicle. The one or more vehicle load sensors may comprise one or more load detection sensors arranged in connection to or comprised in bellows of a vehicle level adjustment system comprising a set of bellows arranged in connection to the respective axles of the chassis of the vehicle.

According to an embodiment the vehicle load determination device 114 may comprise one or more pressure sensors for determining bellows pressure in connection to the respective wheel axle and means for determining the vehicle weight based on the bellows pressure and the vehicle inclination.

According to an embodiment the control device 100, when determining whether reducing the braking force for those wheels of one or more wheel axles where level change may induce chassis stresses may cause the vehicle to move, is configured to determine frictional circumstances for the vehicle.

According to an embodiment the vehicle movement determination arrangement 110 comprises a friction determination device 116 for determining frictional circumstances for the vehicle.

The friction determination device 116 may comprise a surface condition determination device. The surface condition determination device may comprise one or more surface conditions sensors. The surface condition determination device may comprise one or more cameras and/or one or more laser scanners and/or one or more radars.

Thus determined surface conditions may comprise slippery road, i.e. surface of the road, due to e.g. ice on the road, snow on the road, oil on the road, gravel on the road, water on the road, or other road conditions that may affect friction circumstances for the vehicle.

According to an embodiment the control device 100, when determining whether reducing the braking force for those wheels of one or more wheel axles where level change may induce chassis stresses may cause the vehicle to move, is configured to determine weather conditions.

According to an embodiment the vehicle movement determination arrangement 110 comprises a weather determination device 117 for determining current weather conditions.

The weather determination device 117 may comprise one or more weather sensors. The weather sensors may comprise one or more precipitation sensors for detecting rain, snow, hail and the like. The one or more weather sensors may comprise one or more temperature sensors for detecting the current temperature. The one or more weather sensors may comprise one or more wind sensors.

The weather determination device 117 may comprise means for extracting external weather data from one or more external weather data units comprising any suitable external server unit. The weather determination device 117 may comprise one or more external weather data units.

Thus determined weather conditions may comprise rain and extent of rain, snow and extent of snow, current temperature, wind conditions or the like.

According to an embodiment the control device 100, when determining whether reducing the braking force for those wheels of one or more wheel axles where level change may induce chassis stresses may cause the vehicle to move, is configured to determine tire conditions of the vehicle wheels.

According to an embodiment the vehicle movement determination arrangement 110 comprises vehicle tire condition determination device 118 for determining tire conditions of the vehicle wheels.

The tire condition determination device 118 may comprise data about tread patterns of the tires, comprising tread lug, tread void, usage/wear of the tires, tire material, tire pressure etc.

According to an embodiment the control device 100, when determining whether reducing the braking force for those wheels of one or more wheel axles where level change may induce chassis stresses may cause the vehicle to move, is configured to determine whether vehicle service brakes in the driver position are activated.

According to an embodiment the vehicle movement determination arrangement 110 comprises a vehicle brake activation determination device 119 for determining whether vehicle service brakes in the driver position are activated.

The control device 100 is configured to take action so as to prevent such movement if it is determined that thus reducing the braking force may cause the vehicle to move.

The system I may comprise an action taking device 120 arranged to take action so as to prevent such movement if it is determined that thus reducing the braking force may cause the vehicle to move.

The control device 100 may comprise or be operably connectable to the action taking device 120.

According to an embodiment the control device 100, when taking action so as to prevent such movement of the vehicle, is configured to prevent reduction of the braking force for those wheels of one or more wheel axles where level change may induce chassis stresses which may cause the vehicle to move.

The action taking device 120 comprises according to an embodiment a braking force reduction prevention device 122 for preventing reduction of the braking force for those wheels of one or more wheel axles where level change may induce chassis stresses which may cause the vehicle to move. The device 122 may be comprised in the control device 100.

The control device 100 may be configured to inform a vehicle operator that it has been determined that reducing the braking force for those wheels of one or more wheel axles where level change may induce chassis stresses may cause the vehicle to move The action taking device 120 comprises according to an embodiment an information device 124 for informing a vehicle operator that it has been determined that reducing the braking force for those wheels of one or more wheel axles where level change may induce chassis stresses may cause the vehicle to move.

The information device 124 may comprise one or more display units. The one or more display units may comprise the display unit on the instrument panel of the vehicle, a heads up display unit, a display unit providing a display on the front windshield, a display on a remote control unit for controlling the level change of the vehicle, a display on a smart phone and/or tablet of the operator of the vehicle, a light, e.g. a flashing light, on the vehicle, e.g. the roof of the vehicle or the like. The information device 124 may comprise an audible information device. The audible information device may be arranged to provide a voice message, an alarm or the like. The information device 124 may comprise a tactile information device. The tactile information device may be arranged to provide vibrations in the steering wheel, vibrations in the driver seat, vibrations in a remote control unit for controlling the level change of the vehicle or the like in order to alert the vehicle operator. A vehicle operator may for an autonomous vehicle be an operator in a control tower or the like.

According to an embodiment the control device 100, when taking so as to prevent such movement of the vehicle, is configured to determine whether the vehicle operator is in the driver position for braking the vehicle.

The action taking device 120 comprises according to an embodiment a driver position determination device 126 for determining whether the vehicle operator is in the driver position for braking the vehicle. The driver position determination device 126 may according to an embodiment be comprised in and/or be configured to provide input to the vehicle movement determination arrangement 110.

If it is determined that the vehicle operator is in the driver position for braking the vehicle the control device 100 is, according to an embodiment, configured to inform the vehicle operator of required braking of the vehicle by means of the vehicle service brakes so as to allow reduction of parking brake force for those wheels of one or more wheel axles where level change may induce chassis stresses. The control device 100 is configured to reduce the braking force for those wheels of one or more wheel axles where level change may induce chassis stresses by means of the function for reducing the braking force. Thus, if it is determined that the vehicle operator is in the driver position for braking the vehicle the control device 100 may be to reduce the braking force for those wheels of one or more wheel axles where level change may induce chassis stresses. This since the vehicle operator in the driver position may activate the service brakes, if the vehicle start moving.

The information device 124 may be arranged to inform the vehicle operator of required braking of the vehicle by means of the vehicle service brakes.

The control device 100 is configured to, if it is determined that thus reducing the braking force may not cause the vehicle to move, reduce the braking force. The control device 100 is configured to reduce the braking force for those wheels of one or more wheel axles where level change may induce chassis stresses by means of the function for reducing the braking force.

If the vehicle would start to move due to reduction of braking force for those wheels of one or more wheel axles where level change may induce chassis stresses, despite the fact that it was determined that such reduction of braking force may not cause the vehicle to move, the control device 100 is according to an embodiment configured to take action so as to stop the vehicle movement.

The control device 100 may be configured to determine such movement of the vehicle. Such movement of the vehicle may be determined by means of one or more sensors being comprised in or operably connected to the control device 100.

According to an embodiment the control device 100, when taking action so as to stop such movement of the vehicle, is configured to increase the braking force for those wheels of one or more wheel axles where the braking force of the parking brakes have been reduced.

According to an embodiment the control device 100, when taking action so as to stop such movement of the vehicle, is configured to inform a vehicle operator that it has been determined that the vehicle is moving. According to an embodiment the control device is configured to inform a vehicle operator that it has been determined that the vehicle is moving by means of an information device, e.g. the information device 124 or an information device in accordance with the information device 124 or another kind of information device, for informing a vehicle operator that it has been determined that the vehicle is moving. Such an information device may be comprised in or operably connected to the control device 100. The information by the information device may comprise recommendation to activate parking brakes. Parking brakes may according to an embodiment be remotely controllable by any suitable remote control so that the operator, when not being in the vehicle, may control the parking brakes. Such a remote control may be operably connectable to the control device 100.

According to an embodiment of the invention, the control device 100 is, via a link 10, operably connected to the vehicle movement determination arrangement 110. According to an embodiment of the invention, the control device 100 is via the link 10 arranged to receive a signal from the vehicle movement determination arrangement 110 representing data about risk of vehicle movement if the braking force for those wheels of one or more wheel axles where level change may induce chassis stresses is reduced.

According to an embodiment of the invention, the control device 100 is, via a link 12, operably connected to the surface inclination determination device 112. According to an embodiment of the invention, the control device 100 is via the link 12 arranged to receive a signal from the surface inclination determination device 112 representing data about inclination of the surface on which the vehicle is parked.

According to an embodiment of the invention, the control device 100 is, via a link 14, operably connected to the vehicle load determination device 114. According to an embodiment of the invention, the control device 100 is via the link 14 arranged to receive a signal from the vehicle load determination device 114 representing data about vehicle load.

According to an embodiment of the invention, the control device 100 is, via a link 16, operably connected to the friction determination device 116. According to an embodiment of the invention, the control device 100 is via the link 16 arranged to receive a signal from the friction determination device 116 representing data about frictional circumstances for the vehicle.

According to an embodiment of the invention, the control device 100 is, via a link 17, operably connected to the weather determination device 117. According to an embodiment of the invention, the control device 100 is via the link 17 arranged to receive a signal from the weather determination device 117 representing data about current weather conditions.

According to an embodiment of the invention, the control device 100 is, via a link 18, operably connected to the vehicle tire condition determination device 118. According to an embodiment of the invention, the control device 100 is via the link 18 arranged to receive a signal from the vehicle tire condition determination device 118 representing data about tire conditions of the vehicle wheels.

According to an embodiment of the invention, the control device 100 is, via a link 19, operably connected to the vehicle brake activation determination device 119. According to an embodiment of the invention, the control device 100 is via the link 19 arranged to receive a signal from the vehicle brake activation determination device 119 representing data about whether vehicle service brakes in the driver position are activated.

The control device 100 is according to an embodiment arranged to process the data about inclination of the surface on which the vehicle is parked and/or data about vehicle load and/or data about frictional circumstances for the vehicle and/or data about current weather conditions and/or data about tire conditions of the vehicle wheels and/or whether vehicle service brakes in the driver position are activated so as to determine whether risk of vehicle movement if the braking force for those wheels of one or more wheel axles where level change may induce chassis stresses is reduced.

According to an embodiment of the invention, the control device 100 is, via a link 20, operably connected to the action taking device 120. According to an embodiment of the invention, the control device 100 is via the link 20 arranged to send a signal to the action taking device 120 representing data about action to be taken so as to prevent movement of the vehicle. The data about action to be taken may comprise data about preventing reduction of the braking force for those wheels of one or more wheel axles where level change may induce chassis stresses which may cause the vehicle to move. The data about action to be taken may comprise data about informing a vehicle operator that it has been determined that reducing the braking force for those wheels of one or more wheel axles where level change may induce chassis stresses may cause the vehicle to move. The data about action to be taken may comprise data about determining whether the vehicle operator is in the driver position for braking the vehicle.

The control device 100 for controlling parking brakes of a vehicle in connection to level change of the vehicle is, according to an embodiment, adapted to perform the method M1 described below with reference to fig. 4.

Fig. 4 schematically illustrates a flow chart of a method M1 performed by a control device for controlling parking brakes of a vehicle in connection to level change of the vehicle according to an embodiment of the present disclosure.

The vehicle comprises a vehicle level adjustment system having bellows arranged in connection to wheel axles of the vehicle. The bellows are configured to provide level change of the chassis of the vehicle relative to the wheel axle level. Parking brakes are arranged for providing braking force for the wheels of the wheel axles. The control device comprises a function for reducing the braking force for those wheels of one or more wheel axles where level change may induce chassis stresses.

According to the embodiment the method performed by a control device for controlling parking brakes of a vehicle in connection to level change of the vehicle comprises a step S1. In this step it is determined whether reducing the braking force for those wheels of one or more wheel axles where level change may induce chassis stresses may cause the vehicle to move.

According to the embodiment the method comprises a step S2A. In this step, if it is determined that thus reducing the braking force may cause the vehicle to move, action is taken so as to prevent such movement.

According to the embodiment the method comprises a step S2B. In this step, if it is determined that thus reducing the braking force may not cause the vehicle to move, the braking force is reduced.

According to an embodiment of the method the step of determining whether reducing the braking force for those wheels of one or more wheel axles where level change may induce chassis stresses may cause the vehicle to move comprises determining inclination of the surface on which the vehicle is parked. The step of determining inclination of the surface on which the vehicle is parked may be performed by means of an inclination determination device, e.g. an inclination determination device 112 in accordance with fig. 3.

According to an embodiment of the method the step of determining whether reducing the braking force for those wheels of one or more wheel axles where level change may induce chassis stresses may cause the vehicle to move comprises determining one or more of the parameters: load of the vehicle; frictional circumstances for the vehicle; weather conditions; tire conditions of the vehicle wheels. The step of determining load of the vehicle may comprise determining the vehicle axle load of the respective vehicle axle. The step of determining load of the vehicle may be performed by means of a vehicle load determination device, e.g. a vehicle load determination device 114 in accordance with fig. 3. The step of determining frictional circumstances for the vehicle may be performed by means of a friction determination device, e.g. a friction determination device 116 in accordance with fig. 3. The step of determining weather conditions may be performed by means of a weather determination device, e.g. a weather determination device 117 in accordance with fig. 3. The step of determining tire conditions of the vehicle wheels may be performed by means of a tire condition determination device, e.g. a tire condition determination device 118 in accordance with fig. 3.

According to an embodiment of the method the step of determining whether reducing the braking force for those wheels of one or more wheel axles where level change may induce chassis stresses may cause the vehicle to move comprises determining whether vehicle service brakes are activated. The step of determining whether vehicle service brakes are activated may be performed by means of a vehicle brake activation determination device, e.g. a vehicle brake activation determination device 119 in accordance with fig. 3.

According to an embodiment of the method the step of taking action so as to prevent such movement comprises the step of preventing reducing the braking force for those wheels of one or more wheel axles where level change may induce chassis stresses which may cause the vehicle to move.

According to an embodiment of the method the step of taking action so as to prevent such movement of the vehicle comprises determining whether the vehicle operator is in the driver position for braking the vehicle.

According to an embodiment the method comprises the step of, if it is determined that the vehicle operator is in the driver position for braking the vehicle, inform the vehicle operator of required braking of the vehicle by means of the vehicle service brakes so as to allow reduction of parking brake force for those wheels of one or more wheel axles where level change may induce chassis stresses.

If it is determined that the vehicle service brakes are activated providing a braking force, the method comprises, according to an embodiment, the step of reducing the braking force of the parking brakes.

Hereby efficient prevention of movement is obtained, wherein, if the vehicle operator is in the driver position for braking the vehicle, the parking brake force may be reduced due to the fact the operator may brake the vehicle, and, if not, prevention of the reducing the braking force for those wheels of one or more wheel axles where level change may induce chassis stresses which may cause the vehicle to move may be performed.

According to the method, if it is determined that thus reducing the braking force for those wheels of one or more wheel axles where level change may induce chassis stresses may not cause the vehicle to move, the braking force for those wheels are reduced.

If the vehicle would start to move due to reduction of braking force for those wheels of one or more wheel axles where level change may induce chassis stresses, despite the fact that it was determined that such reduction of braking force may not cause the vehicle to move, the method according to an embodiment comprises the step of taking action so as to stop the vehicle movement.

The method comprises according to an embodiment the step of determining such movement of the vehicle. Such movement of the vehicle may be determined by means of one or more sensors being comprised in or operably connected to the control device.

According to an embodiment the step of taking action so as to stop such movement of the vehicle comprises increasing the braking force for those wheels of one or more wheel axles where the braking force of the parking brakes have been reduced so as to stop the movement of the vehicle.

According to an embodiment the step of taking action so as to stop such movement of the vehicle comprises informing a vehicle operator that it has been determined that the vehicle is moving. The information may comprise recommendation to activate parking brakes. Parking brakes may according to an embodiment be remotely controllable by any suitable remote control so that the operator, when not being in the vehicle, may control the parking brakes. Such a remote control may be operably connectable to the control device.

The method M1 performed by a control device for controlling parking brakes of a vehicle in connection to level change of the vehicle is according to an embodiment adapted to be performed by the control device 100 described above with reference to fig. 3.

The method M1 performed by a control device for controlling parking brakes of a vehicle in connection to level change of the vehicle is according to an embodiment adapted to be performed by the system I described above with reference to fig. 3.

With reference to figure 5, a diagram of a computer 500/apparatus 500 is shown. The control device 100 described with reference to fig. 3 may according to an embodiment comprise apparatus 500. Apparatus 500 comprises a nonvolatile memory 520, a data processing device 510 and a read/write memory 550. Non-volatile memory 520 has a first memory portion 530 wherein a computer program, such as an operating system, is stored for controlling the function of apparatus 500. Further, apparatus 500 comprises a bus controller, a serial communication port, l/O-means, an A/D-converter, a time date entry and transmission unit, an event counter and an interrupt controller (not shown). Non-volatile memory 520 also has a second memory portion 540.

A computer program P is provided comprising routines for controlling parking brakes of a vehicle in connection to level change of the vehicle.

The program P comprises routines for determining whether reducing the braking force for those wheels of one or more wheel axles where level change may induce chassis stresses may cause the vehicle to move. The program P comprises routines for, if it is determined that thus reducing the braking force may cause the vehicle to move, taking action so as to prevent such movement. The program P comprises routines for, if it is determined that thus reducing the braking force may not cause the vehicle to move, reducing the braking force.

The routines for determining whether reducing the braking force for those wheels of one or more wheel axles where level change may induce chassis stresses may cause the vehicle to move may comprise routines for determining inclination of the surface on which the vehicle is parked.

The routines for determining whether reducing the braking force for those wheels of one or more wheel axles where level change may induce chassis stresses may cause the vehicle to move may comprise routines for determining one or more of the parameters: load of the vehicle; frictional circumstances for the vehicle; weather conditions; tire conditions of the vehicle wheels.

The routines for taking action so as to prevent such movement of the vehicle may comprise routines for preventing reducing the braking force for those wheels of one or more wheel axles where level change may induce chassis stresses which may cause the vehicle to move.

The routines for taking action so as to prevent such movement of the vehicle may comprise routines for determining whether the vehicle operator is in the driver position for braking the vehicle.

The computer program P may be stored in an executable manner or in a compressed condition in a separate memory 560 and/or in read/write memory 550.

When it is stated that data processing device 510 performs a certain function it should be understood that data processing device 510 performs a certain part of the program which is stored in separate memory 560, or a certain part of the program which is stored in read/write memory 550.

Data processing device 510 may communicate with a data communications port 599 by means of a data bus 515. Non-volatile memory 520 is adapted for communication with data processing device 510 via a data bus 512. Separate memory 560 is adapted for communication with data processing device 510 via a data bus 511. Read/write memory 550 is adapted for communication with data processing device 510 via a data bus 514. To the data communications port 599 e.g. the links connected to the control unit 100 may be connected.

When data is received on data port 599 it is temporarily stored in second memory portion 540. When the received input data has been temporarily stored, data processing device 510 is set up to perform execution of code in a manner described above. The signals received on data port 599 may be used by apparatus 500 for determining whether reducing the braking force for those wheels of one or more wheel axles where level change may induce chassis stresses may cause the vehicle to move. The signals received on data port 599 may, if it is determined that thus reducing the braking force may cause the vehicle to move, be used by apparatus 500 for taking action so as to prevent such movement. The signals received on data port 599 may, if it is determined that thus reducing the braking force may not cause the vehicle to move, be used by apparatus 500 for reducing the braking force.

The signals used by apparatus 500 for determining whether reducing the braking force for those wheels of one or more wheel axles where level change may induce chassis stresses may cause the vehicle to move may comprise signals used for determining inclination of the surface on which the vehicle is parked.

The signals used by apparatus 500 for determining whether reducing the braking force for those wheels of one or more wheel axles where level change may induce chassis stresses may cause the vehicle to move may comprise signals used for determining one or more of the parameters: load of the vehicle; frictional circumstances for the vehicle; weather conditions; tire conditions of the vehicle wheels.

The signals used by apparatus 500 for taking action so as to prevent such movement of the vehicle may comprise signals used for preventing reducing the braking force for those wheels of one or more wheel axles where level change may induce chassis stresses which may cause the vehicle to move.

The signals used by apparatus 500 for taking action so as to prevent such movement of the vehicle may comprise signals used for determining whether the vehicle operator is in the driver position for braking the vehicle.

Parts of the methods described herein may be performed by apparatus 500 by means of data processing device 510 running the program stored in separate memory 560 or read/write memory 550. When apparatus 500 runs the program, parts of the methods described herein are executed.

The foregoing description of the preferred embodiments of the present invention has been provided for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Obviously, many modifications and variations will be apparent to practitioners skilled in the art. The embodiments were chosen and described in order to best explain the principles of the invention and its practical applications, thereby enabling others skilled in the art to understand the invention for various embodiments and with the various modifications as are suited to the particular use contemplated.

Claims

1. A method (M1 ) performed by a control device (100) for controlling parking brakes of a vehicle (V1) in connection to level change of the vehicle (V1), the vehicle (V1) comprising a vehicle level adjustment system having bellows (B1, B2, B3, B4) arranged in connection to wheel axles (X1, X2) of the vehicle (V1 ), the bellows (B1, B2, B3, B4) being configured to provide level change of the chassis (2, 3) of the vehicle relative to the wheel axle level, parking brakes being arranged for providing braking force for the wheels (LF, RF, LD, RD) of the wheel axles (X1, X2), the control device (100) comprising a function for reducing the braking force for those wheels of one or more wheel axles where level change may induce chassis stresses, characterized in that the method comprising the steps of: - determining whether reducing the braking force for those wheels of one or more wheel axles where level change may induce chassis stresses may cause the vehicle (V1 ) to move; - if it is determined that thus reducing the braking force may cause the vehicle (V1) to move, taking action so as to prevent such movement; and, - if it is determined that thus reducing the braking force may not cause the vehicle (V1) to move, reducing the braking force.

2. The method according to claim 1, wherein the step of determining whether reducing the braking force for those wheels of one or more wheel axles where level change may induce chassis stresses may cause the vehicle to move comprises determining inclination (a) of the surface on which the vehicle is parked.

3. The method according to claim 1 or 2, wherein the step of determining whether reducing the braking force for those wheels of one or more wheel axles where level change may induce chassis stresses may cause the vehicle to move comprises determining one or more of the parameters: load of the vehicle; frictional circumstances for the vehicle; weather conditions; tire conditions of the vehicle wheels.

4. The method according to any of claims 1-3, wherein the step of taking action so as to prevent such movement of the vehicle comprises the step of preventing reducing the braking force for those wheels of one or more wheel axles where level change may induce chassis stresses which may cause the vehicle to move.

5. The method according to any of claims 1-4, wherein the step of taking action so as to prevent such movement vehicle comprises determining whether the vehicle operator is in the driver position for braking the vehicle.

6. A control device (100) for controlling parking brakes of a vehicle (V1) in connection to level change of the vehicle (V1), the vehicle (V1) comprising a vehicle level adjustment system having bellows (B1, B2, B3, B4) arranged in connection to wheel axles (X1, X2) of the vehicle (V1), the bellows (B1, B2, B3, B4) being configured to provide level change of the chassis (2, 3) of the vehicle relative to the wheel axle level, parking brakes being arranged for providing braking force for the wheels (LF, RF, LD, RD) of the wheel axles (X1, X2), the control device (100) comprising a function for reducing the braking force for those wheels of one or more wheel axles where level change may induce chassis stresses, characterized in that the control device being configured to: - determine whether reducing the braking force for those wheels of one or more wheel axles where level change may induce chassis stresses may cause the vehicle to move; - if it is determined that thus reducing the braking force may cause the vehicle to move, take action so as to prevent such movement; and, - if it is determined that thus reducing the braking force may not cause the vehicle to move, reduce the braking force.

7. The control device according to claim 6, wherein the control device (100), when determining whether reducing the braking force for those wheels of one or more wheel axles where level change may induce chassis stresses may cause the vehicle to move, is configured to determine inclination (a) of the surface on which the vehicle is parked.

8. The control device according to claim 6 or 7, wherein the control device, when determining whether reducing the braking force for those wheels of one or more wheel axles where level change may induce chassis stresses may cause the vehicle to move, is configured to determine one or more of the parameters: load of the vehicle; frictional circumstances for the vehicle; weather conditions; tire conditions of the vehicle wheels.

9. The control device according to any of claims 6-8, wherein the control device, when taking action so as to prevent such movement of the vehicle, is configured to prevent reduction of the braking force for those wheels of one or more wheel axles where level change may induce chassis stresses which may cause the vehicle to move.

10. The control device according to any of claims 6-9, wherein the control device, when taking so as to prevent such movement of the vehicle, is configured to determine whether the vehicle operator is in the driver position for braking the vehicle.

11. A vehicle (V) comprising a control device (100) according to any of claims 6-10.

12. A computer program (P) for controlling parking brakes of a vehicle in connection to level change of the vehicle, said computer program (P) comprising program code which, when run on an control device (100) or another computer (500) connected to the control device (100), causes the control device to perform the steps according to claim 1-5.

13. A computer readable medium comprising instructions which, when executed by a computer, cause the computer to carry out the method according to anyone of claim 1-5.