SE545082C2

SE545082C2 - Automatic emergency stop method for a vehicle

Info

Publication number: SE545082C2
Application number: SE2051452A
Authority: SE
Inventors: André Claesson; Björn Kopp; Robert Sjödin
Original assignee: Scania Cv Ab
Priority date: 2020-12-14
Filing date: 2020-12-14
Publication date: 2023-03-21
Also published as: CN116390878A; DE112021005877T5; WO2022131992A1; SE2051452A1

Abstract

The present disclosure relates to techniques in the context of vehicles, and more specifically to an automatic emergency stop method for a vehicle (1). According to a first aspect, the disclosure relates to an automatic emergency stop method comprising obtaining (S1) a current position and characteristics of the vehicle (1), and upon detecting (S2) an emergency stop trigger event, determining (S3) a stop position, based on the obtained current position and characteristics of the vehicle. The method further comprises controlling (S5) one or more of the power consuming components (2) to consume power corresponding to a braking power required to brake the vehicle (1) to stop at the determined stop position, and operating the vehicle to stop at the determined stop position by operating the electrical motor (11) reversely while supplying at least a part of the generated power to the controlled power consuming components (2). The disclosure also relates to a control arrangement (10) configured to perform the method, to a vehicle (1) comprising the control arrangement, to a computer program and to a computer-readable medium.

Description

Technical field The present disclosure relates to techniques in the context of vehicles, and more specifically to an automatic emergency stop method for a vehicle. The disclosure also relates to a control arrangement configured to perform the method, to a vehicle comprising the control arrangement, to a computer program and to a computer- readable medium.

Background Energy for propelling electrical vehicles may be stored in special batteries configured to provide a high systern voltage, eg. 65% volt. When deceleratlng a vehicle with the electric motor operating reversely as a generator, excess energy is tyfpically used to charge the battery. To he able to decelerate the vehicle virith the electric motor(s) when the energy storage is full, or when the electric motor is hrolten, some vehicles are equipped with a hralte resistor that can take care ot excess energy during regenerative hralting when the energy storage cannot receive more energy. llowever, some vehicles have no hralte resistor as there is no need for one depending on the vehicles intended operation. This rnay cause problems if there is a tault in the hattery (eg. it the hattery contactors open due to a tault), which means that the hralte energy generated when hraltihg the vehicle with the electrical motor(s) has nowhere to go. ln such a scenario other service hrakes are usually available to decelerate the vehicle. But lt these service hrakes rely on power delivered hy the faulty battery, there is a rislt that these will not tvorlt. l-lence, a situation may occur when lt is hot possible to oral-te the vehicle, which may he devastating in an emergency situation.

Summary lt is an object of the disclosure to provide a solution that enables emergency stopping of a vehicle using the electrical motor(s) also in situations when there is a tault in the hattery (herein reterred to as the energy storage) and there is no hrakerasister vxfith enough capacity to receive the excess energy. it is a further object to provide a nwethod to step the vehicle En a controlled way without drašning the battery or causing damage to components of the vehicle.

According to a first aspect, the disclosure relates to an automatic emergency stop method for a vehicle comprising a plurality of power consuming components and an electrical motor configured to propel the vehicle and to brake the vehicle when reversely operated. The method comprises obtaining a current position and characteristics of the vehicle, and upon detecting an emergency stop trigger event, determining a stop position, based on the obtained current position and characteristics of the vehicle. The method further comprises controlling one or more of the power consuming components to consume power corresponding to a braking power required to brake the vehicle to stop at the determined stop position, and operating the vehicle to stop at the determined stop position by operating the electrical motor reversely while supplying at least a part of the generated power to the controlled power consuming components. By the proposed method, the vehicle can be stopped using only the electrical motor, as power consuming components are controlled to take care of excess energy. ln this way it is possible to emergency stop the vehicle also when the battery is full or faulty. ln some embodiments, the controlling comprises activating different numbers of the power consuming components based on the braking power required to brake the vehicle at the determined stop position. Thereby, the braking power is adjusted based on demand. ln some embodiments, the controlling comprises controlling certain types of power consuming components to consume power, based on the braking power required to brake the vehicle at the determined stop position. This is another way of adjusting the braking power based on demand. ln some embodiments, the controlling comprises controlling the power consuming components to consume different amounts of power, based on the braking powerrequired to brake the vehicle at the determined stop position. ln this way wear and/or damage caused by the controlling can be avoided when possible. ln some embodiments, the method comprises adapting the controlling along a braking distance until the vehicle stands still. By continually controlling the power consuming components along the braking distance, a desirable braking process may be achieved, which considers e.g. passenger comfort or goods. ln some embodiments, the adapting is based on individual properties of the power consuming components. By considering power characteristics of individual power consuming components in the controlling, the generated braking power can be controlled with good accuracy. ln some embodiments, the adapting is based on variations along the braking distance in a braking power required at different positions. Hence, braking power can be adapted to achieve a smooth braking, as braking power may for example be increased in a downhill slope. ln some embodiments, the emergency stop trigger event comprises one or more of: a failure at an energy storage, a failure in a braking system of the vehicle separate from the electrical motor, request for an emergency brake when an energy storage is fully loaded. Hence, an emergency stop may be triggered when any of these events occur. ln some embodiments, the power consuming components comprises one or more of; an A / C converter, an interior heating element, a window heater, a pump, a fan, interior and/or exterior lighting circuit and a gearing component. Hence, different types of power consuming components may be activated to take care of excess energy generated during the emergency stop. ln some embodiments, the obtaining comprises obtaining the current position and characteristics from a vehicle automation system configured to autonomously operate the vehicle. lf the vehicle is operated by a vehicle automation system, thesame can typically provide all information required to stop the vehicle using the proposed method. ln some embodiments, the determining is based on geographic data. Hence, if map information is available this can be used to determine a suitable stop position, e.g. a parking spot. ln some embodiments, the obtained Characteristics comprises one or more of, vehicle speed, vehicle velocity, vehicle acceleration, vehicle weight, vehicle load. Hence, any available parameter related to the braking properties can be used to determine a braking power.

According to a second aspect, the disclosure relates to a computer program comprising instructions which, when the program is executed by a computer, cause the computer to carry out the method according to the third aspect.

According to a third aspect, the disclosure relates to a computer-readable medium comprising instructions which, when executed by a computer, cause the computer to carry out the method according to the third aspect.

According to a fourth aspect, the disclosure relates to a control arrangement for use in a vehicle comprising a plurality of power consuming components and an electrical motor configured to propel the vehicle and to brake the vehicle when reversely operated. The control arrangement is configured to perform the method according to any one of the embodiments according to the first aspect.

According to a fifth aspect, the disclosure relates to a vehicle comprising a plurality of power consuming components, an electrical motor configured to propel the vehicle and to brake the vehicle when reversely operated, and the control arrangement according to the fourth aspect.

Brief description of the drawinqs Fig. 1a illustrates an autonomous vehicle assembled from a set of modules where the proposed technique is implemented.

Fig. 1b illustrates a truck where the proposed technique is implemented.Fig. 2 is a flow chart of an automatic emergency stop method according to the first aspect.

Fig. 3 illustrates example power consumption ofdifferent power consuming devices. Fig. 4 illustrates a control arrangement according to the fourth aspect in more detail. Fig. 5 illustrates how an emergency stop may be performed with the proposed technique.

Detailed description This disclosure proposes that one or more power consumers of a vehicle are controlled in order to be able to emergency stop the vehicle with the electric motor when the energy storage is full or when there is something wrong with it. For example, large power consumers like heaters and air condition units may be used. These large power consumers will then act together as a "brake resistor" and take care of power generated when operating the electrical motor reversely as a generator. ln this way it is possible to stop the vehicle in an emergency situation when the battery is full or faulty, even if the service brakes (electric brakes) do not work for any reason, e.g. due to an electrical fault. The proposed technique will now be explained with reference to Figs. 1 to Fig. "la illustrates ari auteneinetis vehicle 'i asseineled by meduies, where the prepesed technique may be implemented. The iliustrated vehicle l is assembled hy two drive rnedules 3G and ene functional module 4G. By combining drive inedules 3G and iunetienal rncdules 4G in dther ways different types ei vehicles l dan be achieved. Some vehicies l require tvvo er mere drive inodules 3G and some vehicles i enly require ene drive itieciule 3G, ciepending en the structural cenfiguratidn of the functional module 4G. The drive mddules 3G and functional medules 4G comprise a plurality of electrical systems and subsystems. However, for simplicity mainly parts that are associated with the proposed method are shown in Fig. 1a.

The drive module(s)' 30 main function is typically to drive (e.g. propel, steer and brake) a vehicle 1. A drive module 30 comprises a pair of wheels 37 and isconfigured to be autonomously operated. To enable autonomous operation, the drive module 30 comprises sensors 13 (only one shown), e.g. Cameras, radars and lidars, for monitoring the surroundings of the vehicle 1. The drive module 30 also comprise meters 14 (only one shown) for measuring speed, acceleration, temperature, weight etc. and a positioning circuit 16 (e.g. a GPS device) configured to determine the position of the drive module 30 and thereby also the position of the assembled vehicle 1 _ The drive module 30 may also comprise power consuming components such as fans, pumps etc (not shown).

A functional module 40 is configured to perform a certain function such as to carry a load, e.g. goods or people. Each module 30, 40 in the set of modules comprises at least one interface releasably connectable to a corresponding interface of another module 30, ln this example embodiment, each drive module 30 comprises one electric motor 11 connected to the wheels 37. The electric motor 11 may also work as a generator that generates electric energy while braking the wheels 37. Thus, the propulsion system is typically the primary braking system of the vehicle 1. The illuslratecl autonomous moduler vehicle is an example of a vehicle 1 that doesnt necessarily have a brake resistor, as it is typically powered by an energy storage (e.g. a battery) that is large enough to receive all the energy that the electric motor 11 generates when it brakes. A brake resistor is typically large, heavy, complicated to connect to the cooling water circuit, requires electronics, fans, etc. Hence, it may be advantages to omit the braking resistor if it is normally not used. After all, all the energy absorbed by the brake resistor is always a pure loss.

Because the braking funclienallty system may ln seme elluatlcns be lneuiflclerit er fail for some reason, an auxillary braking system (net shown) is typically also implemented. The auxillary braking system comprises for example standard disc brakes and elecfromechanical actuafors that require reliable power suppiy. ln some embodiments the drive module 30 comprises at least one energy storage (not shown) for providing the propulsion system with energy. The energy storage isfor example a battery that may be recharged with electric energy. The energy storage may be of limited size and insufficient to supply power to the propulsion system and receive power from the braking system while operating the vehicle 1. Hence, in some embodiments the energy storage in the drive module 30 is mainly used while assembling the vehicle 1 and/or transporting the drive module 30 without load.

The control arrangement 10 of the drive module 30 is configured to operate the drive module 30 as an independently driven unit. Thus, the control arrangement 10 is configured to drive, reverse, brake and stop the vehicle 1. Thus, the drive module 30 may transport itself without any externally driven unit such as a towing vehicle. The assembled vehicle 1 is operated by the control arrangements 10 of the two drive modules 30 in cooperation (e.g. in a master slave configuration). The drive modules 30 are configured to be autonomously operated by a vehicle automation system that assigns missions. The vehicle automation system controls all functions of the assembled vehicle 1 based on vehicle data provided by the sensors 13 and meters 14. ln other words, the vehicle automation system may control assembly of the vehicle 1 and may after assembly control the vehicle 1 to perform missions (e.g. transport of goods or people), without any driver being present. The vehicle automation system may be implemented on-board (in one of the control arrangements 10) or off-board or by a combined solution where some parts are implemented off-board and the rest on-board. The control arrangement 10 is described in further detail below, with reference to Fig. ln this example embodiment, the functional module 40 needs to be connected to at least one drive module 30 to be able to move. The functional module 40 may comprise a space 41 for accommodating or supporting a load. The at least one functional module 40 may be configured for transporting goods and may thus function as a truck when being assembled with at least one drive module 30. Power consuming components 2 (in Fig. 1a denoted 2a, 2b, 2c) such as a fan 2a, a heating element 2b and an air condition unit 2c may be located in the space 41. The functional rfiocluie 40 also compriaes an energy storage 12 (typšcally a battery).Even though a connected drive modtiie 3G might aiso comprise an energy storage it may not ioe iarge enough energy to propei and hirake the entire vehicie t during iiorrnai operation. t-ience, tvhen operating the vehicie i, the energy storage 12 of the ftinotionei inodtiie 4G typioaiiy suppiies power to the drive rnoduies 3% when driving and receives power virhen braking the vehioie 1. The energy storage 12 is tyoicaiiy aiso used to power the povver consiiming components 2. in this exampie the power consuming components 2 ere connected to the sente tDC-circtiit as the eiectrioai inotor "ii and the energy storage 12. Controiiabie svvitches 15 are erranged such that the controi arrengement tt) oi the drive moduie 3G can disconnect one or more ot the power' consuming components 2 or the energy storage trorn the üßcirotiit. it the energy storage 12, or an interface of the energy storage, is broken or faulty, the main braking system of the assembled vehicle 1 will stop working, as power generated by the electrical motor 11 when operated reversely as a generator has nowhere to go. ln addition, the auxiliary brakes may fail as they are dependent on power supply from the energy storage 12. ln such a situation an emergency stop method is needed.

Fig. ih iiitistretes another vehicie i, more specificeiiy an eiectricaiiy driven truck, virhere the proposed technique may aiso he impiemented. The vehicie ot iïig to is e manuaiiy operated vehicie 1 cornprising e driver assistance system that aseists a driver in for exarnpie driving and parking. in some einhodirnents, the vehicie i is configured to he operated in an atitonornoiis mode, where the vehicie can itseif (e.g. under driver supervision) perform aii driving tasi-ts and nionitor the driving environment. The vehicle 1 comprises a plurality of electrical systems and subsystems. However, for simplicity only some parts of the vehicle 1 that are associated with the proposed method are shown in Fig. 1b. Thus, the iiiustrated vehicie t ot Fig. to comprises an energy storage 12, an eiectricai :notor tt, a piuraiity ot power consdming components 2a-2h and a controi arrangement "iti in addition, the vehicle 1 comprises sensors 13 (only one shown) e.g. cameras, radars and lidars for monitoring its surroundings. The vehicle 1 also comprises meters(only one shown) for measuring speed, acceleration, temperature, weight etc. and a positioning circuit (e.g. a GPS device) configured to determine the position of the vehicle The eiectršcat ntotez' 11 is configured to propei the vehäcte 1 using energy frem the energy storage and to brake the vehšcte 1 when ret/ereely operated. En actdštien, the vehicte cemprises auxiliary brakes e.g. disc: er drum brakes (net shown), that may rety on etectršcal power supply.

The vehicle 1 also comprises a plurality of power consuming components 2 (two shown). The power consuming components are for example one or more of; an air condition unit, an interior heating element, a window heater, a pump, a fan, interior and/or exterior lighting circuit, a levelling system and a gearing component. ln the illustrated embodiment, the power consuming components 2 are powered by the energy storage 12 and/or directly by energy generated by the electric motor 11 when reservedly operated. ln some embodiments, the vehicle comprises controllable switched arranged to disconnect the energy storage 12 or the power consuming components 2 from the electrical motor in the same way as in Fig.1a (not shown).

The control arrangement 10 is configured to receive data from the sensors 13, meters 14 and positioning device 16. ln some embodiments, the control arrangement 10 is configured to provide driving assistance information to a driver of the vehicle. ln some embodiments, the control arrangement 10 is configured to control operation of the vehicle 1 in at least certain situations, e.g. the control arrangement 10 may implement an emergency stop function or a vehicle automation system. The control arrangement is also configured to control operation of the power consuming components 2. The control arrangement 10 is described in further detail below with reference to Fig.

The auxitšery brakes are typically used (sometimes in combination with the electric motor brake) to brake the vehicle 1 in an emergency situation. lf the auxiliary brakes fail it is possible to brake the vehicle 1 using only the electrical motor. However, if lO the energy storage 12 is full, or if the energy storage 12 (or an interface of the energy storage) is broken or faulty, the power generated by the electrical motor 11 when operated reversely as a generator has to go somewhere else in order to provide the braking power required to stop the vehicle 1. Eveh lf the vehicle of Fig. "lb would celrlprlse a brake resleter, the brake resleter may het be iarge eneugh to take care of alá power that vtfouåd be generated tfvheh emergency etepplhg the vehicle 1, tlslhg ehiy the electrical meter 11. ln such a situation an alternative emergency stop method is also needed.

To avoid situations where the vehicles of Fig. 1a and Fig. 1b cannot be braked or stopped, this disclosure proposes an automatic emergency stop method where braking torque is generated by activating power consuming components. The method is for use in situations when an emergency stop is required. For example, it is for use when a main braking system of the vehicle 1 is not fully operable, e.g. because the energy storage is full or broken and when auxiliary brakes do not function properly.

Fig. 2 illustrates the proposed automatic emergency stop method for a vehicle 1 comprising a plurality of power consuming components 2 and an electrical motor 11 configured to propel the vehicle 1 and to brake the vehicle 1 when reversely operated. ln some embodiments, the power consuming components comprises one or more of; an A / C converter, an interior heating element, a window heater, a pump, a fan, interior and/or exterior lighting circuit, a levelling system, and a gearing component.

The method may be implemented as a computer program comprising instructions which, when the program is executed by a computer (e.g. a processor in the control arrangement 10 (Fig. 4)), cause the computer to carry out the method. According to some embodiments the computer program is stored in a computer-readable medium (e.g. a memory or a compact disc) that comprises instructions which, when executed by a computer, cause the computer to carry out the method. ln some embodiments, the method is implemented in a control arrangement 10 of a vehicle, e.g. in the vehicle of Fig. 1a or 1b. ln some embodiments, the method is at least ll partly implemented off-board in a remote vehicle automation system. The method can be performed any time during driving when an emergency stop is needed. The method may be performed during autonomous operation, or alternatively during manual operation.

The proposed concept is based on the insight that most vehicles today (or their automation systems), have at least some knowledge about their surroundings as well as about vehicle characteristics such as load and speed.

This information can be utilized when emergency braking the vehicle. Thus, the proposed method comprises obtaining S1 a current position and characteristics of the vehicle 1. The obtained characteristics refers to any vehicle properties that influence braking behavior. ln some embodiments the characteristics of the vehicle are vehicle properties that influence a braking power required to stop the vehicle. The obtained characteristics comprises for example vehicle speed, vehicle velocity, vehicle acceleration, vehicle weight, vehicle load. ln some embodiments, the characteristics of the vehicle are obtained from one or more sensors 13 and/or meters 14 in the vehicle. ln some embodiments, the vehicle position is obtained from a positioning device 16 of the vehicle. ln practice, the position and/or the characteristics of the vehicle may be obtained in any other suitable way. ln some embodiments, the vehicle 1 is autonomous as the vehicle of Fig. 1a. ln some embodiments, the vehicle 1 has an autonomous mode where the driver has transferred the ability to drive to a vehicle automation system that controls all functions (even though the driver may be alert and ready to take action at any moment). lf the vehicle is at least partly autonomously operated, a vehicle automation system handles monitoring of vehicle and its surroundings and could therefore typically directly provide all information relevant to stop the vehicle. ln other words, in some embodiments, the obtaining S1 comprises obtaining the current position and characteristics from a vehicle automation system configured to autonomously operate the vehicle.Sometimes the vehicles (or the vehicle automation system) also has more or less continual access to map data or geographical data, which is for example retrieved from a geographical database. The geographical data may be two-dimensional or three-dimensional. Geographical data can provide information about e.g. routes, slopes, obstacles, parking spaces etc. ln other words, in some embodiments the method comprises the step of obtaining S0 geographical data. This step can be performed continually, before and/or after step S An emergency stop is typically triggered by certain emergency stop trigger events. For example, the emergency stop trigger event comprises that the energy storage 12 is faulty or that any other serious incident (e.g. overheating) is detected. Hence, in some embodiments, the method comprises detecting S2 an emergency stop trigger event. The emergency stop trigger event comprises for example a failure at an energy storage, a failure in a braking system of the vehicle separate from the electrical motor, or a request for an emergency brake when an energy storage is fully loaded. ln some embodiments, the emergency stop is triggered by an "emergency shut down" request. ln the vehicle 1 of Fig. 1a, an "emergency shut down" is an emergency stop trigger event that may be activated by a passenger or by an off-board operator. ln the vehicle 1 of Fig. 1b, an emergency stop trigger event may be that the driver pushes an "emergency stop button" (or the brake pedal) or that an obstacle (e.g. a person) is detected in front of the vehicle. ln some embodiments, the proposed emergency stop method is triggered when other service brakes e.g. disc brakes are dysfunctional.

A vehicle 1 that has obtained its current position and vehicle characteristics (and possibly also map data) has enough information required to determine (or at least estimate) a suitable place to emergency stop, herein referred to as a stop position. The stop position depends on how urgent the stop is and also on an estimated braking distance. The braking distance is typically dependent on vehicle characteristics such as vehicle speed, load, and available braking power. Even if all these parameters are not known, it is still possible to estimate a stop position based on what is known. Stated differently, the method further comprisesdetermining S3 a stop position, based on the obtained current position and characteristics of the vehicle, upon detecting S2 an emergency stop trigger event. lt must be appreciated that the determination of the stop position may be either very sophisticated or very simple. ln a very simple implementation, the stop position may be determined to be a position 10 meters right ahead of the vehicle. This is applicable for example in a scenario where an object is detected in front of the vehicle and 10 meters is an estimated stopping distance, based on current load and speed.

Alternatively, the stop position may be a specific position e.g. on a map. For example, the stop position is a parking space. This kind of determination is typically applicable in a fully autonomous vehicle, where the vehicle automation system also has access to geographic data. The vehicle (or the vehicle automation system) may then, while also considering the urgency of the stop, determine a suitable place for the vehicle to stop. ln other words, in some embodiments, the determining S3 of a stop position is also based on geographic data.

From the vehicle characteristics and the stop position it possible to estimate a braking power required to stop the vehicle 1 at the stop position. For example, the vehicle 1, i.e. the control arrangement, knows vehicle characteristics such as the instantaneous vehicle weight, the slope of the road and the stopping distance. ln other words, the method typically comprises determining S4 a braking power required to stop the vehicle at the determined stop position.

An amount of energy that will be generated along a breaking distance up to the stop position while braking the vehicle using the electrical motor 11 corresponds to the determined braking power. The proposed technique involves using the one or more of the power consuming components 2 to take care of this energy. Hence, the method further comprises controlling S5 the one or more of the power consuming components 2 to consume power corresponding to a braking power required to brake the vehicle 1 to stop at the determined stop position. The controlling is for example done by sending control data to the power consuming components 2. For example, control data causes the power consuming components 2 to be activated.The control data may also control the power consuming components 2 to consume different amount of power. This may for example be done by changing a speed of a pump or a temperature of a heater. ln some embodiments, the controlling S5 comprises controlling the electrical switches 15 to disconnect the energy storage 12 from the electrical motor 11. ln this way generated electricity can be sent directly to the consumers and is not affected by limitations in the energy storage The vehicle 1 can then be stopped by operating the electrical motor 11 as a generator and feeding the generated power directly to the power consuming components. ln other words, the method then comprises operating S6 the vehicle to stop at the determined stop position by operating the electrical motor 11 reversely while supplying at least a part of the generated power to the controlled power consuming components 2. This may be done by disconnecting the energy storage and supplying the power directly to the power consuming components 2. Stated differently, in some embodiments, the power is supplied directly to the power consuming components. ln some embodiments, all the generated energy is supplied to the power consuming components 2. However, in some embodiments, a part of the generated power may be absorbed by a brake resistor (if present) or fed to the energy storage 12 (if it can receive any power). lf the braking distance is short and the vehicle speed is high the required braking power may be very high. Then it may be required to activate all the power consuming components 2 immediately. However, in other scenarios it might be enough to activate only a few of them. ln other words, in some embodiments the controlling S5 comprises activating different numbers (i.e. different counts) of the power consuming components 2 based on the braking power required to brake the vehicle at the determined stop position and information defining the braking power absorbable by the individual components.

The controlling may also involve controlling operation of the power consuming components 2. For example, a heater or pump may be controlled to operate at maximum effect or speed if a very large braking power is required to stop the vehicle. Note that this may imply that the components are performing an action that is not at all needed, or that may cause wear or even damage in the component. However, the damage caused if the vehicle 1 is not stopped may in some situations be even worse. Hence, it may be preferred that a power consuming component has to be replaced if the alternative is a serious accident. Stated differently, in some embodiments the controlling S5 comprises controlling the power consuming components 2 to consume different amount of power, based on the braking power required to brake the vehicle 1 at the determined stop position.

As discussed above the vehicle 1 may comprise power consuming components 2 of different types. The amount of power consumed is typically different for different components and may also vary over time. Some components are inert and will not start to consume power until after a certain time. Some components e.g. fans can be caused to consume more power if they are controlled not to have a constant speed, but to instead have a pulsed speed. Fig. 3 illustrate power consumption of a compressor (left), a light bulb (middle) and a heater (right). By activating the components 2 in different combinations, and at different times, an instantaneous amount of power (that corresponds to a desired braking power) is consumed. ln other words, in some embodiments, the adapting S5a is based on individual properties of the power consuming components 2. ln some embodiments, the controlling S5 comprises controlling certain types of power consuming components 2 to consume power, based on the braking power required to brake the vehicle 1 at the determined stop position. ln this way the consumed power can be adjusted to for example enable a fast braking or match a smooth braking process where braking power is evenly distributed along the stop distance. lf it is desirable to brake as fast as possible, it would typically be desirable to activate all power consuming components 2 at maximum power at once. However, for a more controlled emergency stop, it may be better to distribute braking power along the braking distance up to the stop position. Hence, in some embodiments the controlling is performed such that the braking power is adjusted at individual points in time during the deceleration. ln practice, this means that the control parameters used to control the power consuming components 2 are repeatedly or continuallyreconfigured along the road. ln other words, in some embodiments, the method comprises adapting S5a the controlling S5 along a braking distance until the vehicle stands still. For example, more and more components are activated until the vehicle stands still. ln some embodiments, the adapting S5a is based on variations along the braking distance in a braking power required at different positions. For example, additional components are activated if there is a downhill slope.

Now turning to Fig. 4 which illustrates the control arrangement 10 configured to implement the proposed emergency stop method of Fig. 2 in more detail. ln some embodiments, the control arrangement 10 is a "unit" in a functional sense. Hence, in some embodiments the control arrangement 10 is a control arrangement comprising several physical control arrangements that operate in corporation.

The control arrangement 10 comprises one or more ECUs. An ECU is basically a digital computer that controls one or more electrical systems (or electrical sub systems) of the vehicle 1 based on e.g. information read from sensors 13 and meters 14 placed at various parts and in different components of the vehicle 1. ECU is a generic term that is used in automotive electronics for any embedded system that controls one or more functions of the electrical system or sub systems in a transport vehicle. The vehicle 1 typically comprises a plurality of ECUs that communicate over a Controller Area Network, CAN, which in the future might be replaced by for example ethernet based solutions. ln some embodiments, at least some parts of the control arrangement 10 are implemented off-board e.g. by an external system The control arrangement 10, or more specifically the processor 101 of the control arrangement 10, is configured to cause the control arrangement 10 to perform all aspects of the method described above and below. This is typically done by running computer program code stored in the data storage or memory 102 in the processor 101 of the control arrangement 10. The data storage 102 may also be configured to store semi-static vehicle parameters such as vehicle dimensions.The control arrangement 10 may also comprise a communication interface (not shown) for communicating with other control units of the vehicle and/or with external systems More specifically the control arrangement is configured to obtain a current position and characteristics of the vehicle. ln some embodiments, the control arrangement 10 is configured to upon detecting an emergency stop trigger event, determine a stop position, based on the obtained current position and characteristics of the vehicle 1, ln some embodiments, the control arrangement 10 is configured to control one or more of the power consuming components 2 to consume power corresponding to a braking power required to brake the vehicle 1 to stop at the determined stop position, and to operate the vehicle 1 to stop at the determined stop position by operating the electrical motor 11 reversely while supplying at least a part of the generated power to the controlled power consuming components Fig. 5 illustrate how an emergency stop may be performed with the proposed technique. Fig. 5 illustrates a vehicle 1 driving on a road 3. A plurality of other vehicles 1' are also driving on the road ln this example, faults on energy bearings and electric brakes are detected by the vehicle 1. The faults may e.g. be missing data communication, error messages, etc. An emergency stop is then activated (step S2 of Fig. 2) by the vehicle 1. lt can be done by the vehicle itself or by a driver/operator). The vehicle 1 (or an off board system 20) calculates (step S3 of Fig. 2) a suitable place to stop using data available in the vehicle e.g. provided by sensors 13 and meters 14 in the vehicle 1 in combination with information from a control tower (off board) that has detailed information about the vehicle's location and surroundings. For example, a parking spot 4 located 150 m ahead is considered a suitable place to a stop. Based on the calculated suitable stopping place, the desired braking effect is calculated (step S4 of Fig. 2). This is possible as the vehicle 1 knows the instantaneous vehicle weight, the slope of the road (e.g. 3 % uphill) and the stopping distance 5 (150m). One /several power consuming components 2 are then activated (step S5 of Fig. 2) depending on the braking power requirement (e.g. all interior lighting is switched on, full A/C and/or heating is activated, etc.). The propulsion motors can now be used for deceleration (step S6 of Fig. 2) with the same power that the power consumers momentarily manage to get rid of.

The terminology used in the description of the embodiments as illustrated in the accompanying drawings is not intended to be limiting of the described method, control arrangement or computer program. Various changes, substitutions and/or alterations may be made, without departing from disclosure embodiments as defined by the appended claims.

The term "or" as used herein, is to be interpreted as a mathematical OR, i.e., as an inclusive disjunction; not as a mathematical exclusive OR (XOR), unless expressly stated otherwise. ln addition, the singular forms "a", "an" and "the" are to be interpreted as "at least one", thus also possibly comprising a plurality of entities of the same kind, unless expressly stated otherwise. lt will be further understood that the terms "includes", "comprises", "including" and/ or "comprising", specifies the presence of stated features, actions, integers, steps, operations, elements, and/ or components, but do not preclude the presence or addition of one or more other features, actions, integers, steps, operations, elements, components, and/ or groups thereof. A single unit such as e.g. a processor may fulfil the functions of several items recited in the claims.