DE102023102838A1 - METHOD AND CONTROL ARRANGEMENT FOR CONTROLLING A SPEED OF A VEHICLE WITH A REGENERATIVE BRAKING SYSTEM - Google Patents

Abstract

Method performed by a control arrangement for controlling a speed of a vehicle with a regenerative braking system.The method includes, when driving downhill, automatically applying a first braking force to keep the vehicle's speed at a set speed level, vmax, when this set speed level, vmax, has been reached. As soon as the vehicle approaches the end of a downhill section of road while the vehicle's speed is controlled to maintain it at the set speed level, vmax, the braking force applied is increased from the first Braking force adjusted to a second braking force to accelerate the vehicle to an increased vehicle speed, vsch, exceeding the set speed level, vmax, the second braking force being applied at least by the regenerative braking system. Hereby the energy efficiency of the regenerative braking system is increased, resulting in an increase in vehicle efficiency and range of the vehicle. The invention also relates to a control arrangement, a vehicle with the control arrangement, a computer program and a computer-readable medium.

Description

technical field

The invention relates to a method and a control arrangement for controlling a speed of a vehicle with a regenerative braking system.

The invention also relates to a computer program and a computer-readable medium and a vehicle with such a control arrangement.

background

The following background description constitutes a description of the background of the invention, which does not necessarily constitute prior art.

One of the biggest global challenges today is reducing the negative environmental impact of road transport due to greenhouse gas emissions. Also, the efficiency of a vehicle's energy consumption is one of the most important factors affecting the cost, performance and competitiveness of the vehicle. This has led to increased interest in solutions designed to improve the energy efficiency of vehicles.

Vehicles today, including heavy vehicles such as trucks and buses, are often equipped with speed control systems designed to maintain a set speed. When driving downhill, gravity acts on the vehicles in such a way that their speed increases. Therefore, downhill speed control, also often referred to as hill descent control, generally involves braking the vehicle.

In certain types of vehicles, such as hybrid and electric vehicles, that have a regenerative braking system, part of the energy required for braking can be recovered. For example, speed control when driving downhill through regenerative braking contributes to greater vehicle energy efficiency.

In addition, lower energy consumption can be achieved by downhill speed control functions, in which the actual speed of the vehicle differs from a predetermined, e.g. B. may deviate from the speed selected by the driver. For example, the speed of the vehicle may be increased above an otherwise maintained maximum speed when the vehicle enters a final portion of the downhill road segment. This increase in speed has the consequence that less braking power is required and that the vehicle leaves the downhill section of road with increased kinetic energy, which can be used instead of the energy stored in fuel or a battery, e.g. B. can be used in a following road section.

Summary

It is an aim of the present invention to provide a method and a control arrangement to reduce or solve the disadvantages of conventional solutions. In particular, it is an aim of the present invention to provide a solution for controlling a speed of a vehicle with a regenerative braking system, while achieving improved energy efficiency in the vehicle.

• Einstellen der aufgebrachten Bremskraft von der ersten Bremskraft auf eine zweite Bremskraft, um das Fahrzeug auf eine erhöhte Fahrzeuggeschwindigkeit, v_sch, zu beschleunigen, die das eingestellte Geschwindigkeitsniveau, v_max, übersteigt, wobei die zweite Bremskraft durch mindestens das regenerative Bremssystem aufgebracht wird.

According to a first aspect of the invention, the above and other objects are achieved by a method carried out by a control arrangement for controlling a speed of a vehicle, the vehicle comprising a regenerative braking system, the method comprising that when driving downhill automatically a first braking force is applied to control the speed of the vehicle so that it is maintained at a set speed level, v _max , when this set speed level, v _max , is reached,
the method further comprising when the vehicle approaches the end of a downhill road segment while controlling the speed of the vehicle to maintain it at the set speed level, V _max :

• Adjusting the applied braking force from the first braking force to a second braking force to accelerate the vehicle to an increased vehicle speed, v _sch , that exceeds the set speed level, v _max , the second braking force being applied by at least the regenerative braking system.

The invention thus relates to a method for controlling a speed in an electric vehicle that includes a regenerative braking system. Examples of such vehicles are battery electric vehicles, hybrid electric vehicles, and plug-in hybrid electric vehicles. The regenerative braking system may include an electric machine that operates as an electric generator during vehicle braking so that some of the braking energy can be recovered.

The invention controls the speed of the vehicle by applying a braking force, referred to herein as the second braking force, at least in part by the regenerative braking system while accelerating the vehicle to the increased vehicle speed v _sch .

By applying the second braking force using the regenerative braking system, more of the braking energy can be recovered during the increase in speed than if no brakes were applied.

In addition, the invention allows the speed increase to begin at an earlier point in time than the speed increase according to the previously known methods. This means that the vehicle's average speed increases, resulting in a reduction in travel time. In addition, the peak braking force is reduced during the part of the speed increase in which the set speed level v _max would have been maintained if the speed increase had been carried out according to the previously known methods. By reducing the peak braking force, the electrical losses in the vehicle are reduced. This increases the energy efficiency of the regenerative braking system, which leads to an increase in vehicle efficiency and the range of the vehicle. In addition, the temperature of the electric motor and battery components can be lowered, resulting in less risk of motor overheating and more efficient energy recovery.

In one embodiment of the invention, adjusting the applied braking force includes reducing the applied braking force from the first braking force to the second braking force.

The second braking force can therefore be a smaller braking force than the first braking force. As a result, the invention can be applied in downhill road sections where a first braking force is required in order to keep the vehicle's speed at a set speed level v _max . This applies, for example, in situations where the downhill road section is long enough and/or steep enough to accelerate the vehicle from an initial speed at the beginning of the downhill road section to a speed that exceeds the set speed level v _max before it approaching the end of the downhill stretch of road when no braking force has been applied.

The reduction of the braking force in the downhill road section from the first braking force to the second braking force is such that the forces acting on the vehicle accelerate the vehicle and the speed of the vehicle increases. As already explained, since the second braking force is at least partially applied by the regenerative braking system of the vehicle, part of the braking energy can be recovered. This increases the efficiency of the regenerative braking system when the vehicle is traveling on roads with long and/or steep downhill sections.

In one embodiment of the invention, the second braking force is applied solely by the regenerative braking system.

By having the second braking force applied solely by the regenerative braking system, a greater amount of energy can be recovered by the regenerative braking system in the vehicle. This increases the energy efficiency of the vehicle.

In one embodiment of the invention, the increased vehicle speed v _sch exceeding the set speed level v _max is based on at least one of the following: a preset speed level, the set speed level v _max and/or a period of time in which the vehicle has exceeded the set speed level v _max exceeds.

Increasing the speed of the vehicle in the last part of the downhill road section can result in the vehicle exiting the downhill road section with increased kinetic energy. The increased kinetic energy can be used instead of energy stored in fuel or a battery on a road section following the descent, which can result in lower energy consumption than if the set speed level v _max were maintained until the end of the descent. The amount of kinetic energy available at the end of the downhill road segment depends at least on the magnitude of the increased speed level. Using the method of the present invention, the magnitude of the increased velocity level can be controlled in a number of ways. For example, the magnitude of the increased speed level may be controlled to optimize energy efficiency, vehicle driver acceptability, other road user acceptability, and/or driver comfort.

• Bestimmen der zweiten Bremskraft, die es dem Fahrzeug ermöglicht, bei ihrer Anwendung die erhöhte Fahrzeuggeschwindigkeit v_sch zu erreichen, die das eingestellte Geschwindigkeitsniveau v_max übersteigt, wenn das Fahrzeug das Ende des bergab führenden Straßenabschnitts erreicht, wobei das Einstellen der aufgebrachten Bremskraft ferner ein Aufbringen der bestimmten zweiten Bremskraft umfasst, so dass das Fahrzeug auf die erhöhte Fahrzeuggeschwindigkeit v_sch beschleunigt wird.

In an embodiment of the invention, the method further comprises when the applied braking force is adjusted:

• determining the second braking force which, when applied, enables the vehicle to reach the increased vehicle speed v _sch exceeding the set speed level v _max when the vehicle reaches the end of the downhill road section, adjusting the applied braking force further comprising applying the determined second braking force, so that the vehicle is accelerated to the increased vehicle speed v _sch .

By determining the second braking force according to aspects of the invention, the speed of the vehicle can be controlled so that the increased vehicle speed v _sch is reached and at the end of the downhill road section, when the vehicle is no longer being accelerated through the downhill road section, the maximum available kinetic energy is gained. This optimizes the energy efficiency of the vehicle when driving downhill.

In one embodiment of the invention, determining the second braking force is based at least in part on one or more of the following: road grade data of the downhill road section, a curvature of the downhill road section, a weight of the vehicle, an aerodynamic drag force acting on the vehicle, and/or a Traffic situation within the downhill road section.

The second braking power can be determined in such a way that energy recovery is optimized when the speed is increased and at the same time the speed of the vehicle is adapted to the vehicle properties and the prevailing road conditions.

• eine Geschwindigkeit des Fahrzeugs auf dem bergab führenden Straßenabschnitt,
• die erste Bremskraft, die auf dem bergab führenden Straßenabschnitt aufgebracht wird, und/oder
• eine Wärmeentwicklung im regenerativen Bremssystem.

In one embodiment of the invention, determining the second braking force is further based on at least one of the following:

• a speed of the vehicle on the downhill road segment,
• the first braking force applied on the downhill road section, and/or
• heat generation in the regenerative braking system.

This achieves the same advantages as described above. In addition, the braking force to be applied during the increase in speed can be adjusted in such a way as to reduce the risk of the regenerative braking system overheating and/or jerky movements of the vehicle, e.g. H. rapid changes in acceleration when releasing the vehicle brakes are avoided.

In an embodiment of the invention, the determined second braking force may change dynamically along the downhill road segment.

Thereby, the second braking force to be applied during the speed increase can be controlled so that a required speed increase is achieved even when the gradient of the downhill road portion changes.

• Bestimmen einer Position in dem bergab führenden Straßenabschnitt vor dem Fahrzeug, an der die aufgebrachte Bremskraft einzustellen ist, um das Fahrzeug zu beschleunigen, um die erhöhte Fahrzeuggeschwindigkeit v_sch zu erreichen, die das eingestellte Geschwindigkeitsniveau v_max übersteigt, und
• Einstellen der aufgebrachten Bremskraft bei Erreichen der genannten Position.

In an embodiment of the invention, the method further comprises:

• determining a position in the downhill road section in front of the vehicle at which to adjust the applied braking force to accelerate the vehicle to attain the increased vehicle speed v _sch exceeding the adjusted speed level v _max , and
• Setting the applied braking force when reaching the specified position.

By determining a position at which to adjust the braking force according to an aspect of the invention, the duration of the vehicle's speed increase at which regenerative braking power is applied can be controlled. This allows the amount of energy regenerated during the increase in speed to be optimized.

In one embodiment of the invention, determining the position is based at least in part on road grade data of the downhill road segment.

This allows the amount of regenerated energy to be reliably controlled during speed increase in all downhill sections.

In one embodiment of the invention, determining said position is based on the determined second braking force.

This allows the amount of regenerated energy to be reliably controlled and optimized during speed increase.

• Aufbringen einer regenerativen Bremskraft, bevor das Fahrzeug das eingestellte Geschwindigkeitsniveau v_max erreicht; und
• Steuern eines Niveaus der regenerativen Bremskraft, so dass das Fahrzeug das eingestellte Geschwindigkeitsniveau v_max erreicht, vor oder an der Position, an der die aufgebrachte Bremskraft von der ersten Bremskraft auf die zweite Bremskraft eingestellt wird, um das Fahrzeug weiter zu beschleunigen.

In an embodiment of the invention, the method further comprises:

• applying a regenerative braking force before the vehicle reaches the set speed level v _max ; and
• controlling a level of regenerative braking force so that the vehicle reaches the set speed level v _max before or at the position where the applied braking force is adjusted from the first braking force to the second braking force to further accelerate the vehicle.

This can further increase the amount of regenerated energy on the downhill road section.

• vor dem Einstellen der aufgebrachten Bremskraft zum Beschleunigen des Fahrzeugs auf eine erhöhte Fahrzeuggeschwindigkeit v_sch, die das eingestellte Geschwindigkeitsniveau v_max übersteigt, die Fahrzeuggeschwindigkeit zumindest teilweise mit Hilfe des regenerativen Bremssystems auf dem eingestellten Geschwindigkeitsniveau v_max gehalten wird.

In one embodiment of the invention, the method comprises:

• before adjusting the braking force applied to accelerate the vehicle to an increased vehicle speed v _sch that exceeds the set speed level v _max , the vehicle speed is maintained at the set speed level v _max at least partially with the aid of the regenerative braking system.

This can further increase the amount of regenerated energy on the downhill road section.

• Einstellen der aufgebrachten Bremskraft von der ersten Bremskraft auf eine zweite Bremskraft, um das Fahrzeug auf eine erhöhte Fahrzeuggeschwindigkeit v_sch zu beschleunigen, die das eingestellte Geschwindigkeitsniveau v_max übersteigt, wobei die zweite Bremskraft durch mindestens das regenerative Bremssystem aufgebracht wird.

According to a second aspect, the invention relates to a control arrangement for controlling a speed of a vehicle, the vehicle comprising a regenerative braking system, the control arrangement being configured for, when the vehicle is going downhill, automatically applying a first braking force to reduce the speed of the vehicle to be controlled so that it is maintained at a set speed level v _max when this set speed level v _max is reached,
wherein the control arrangement is further configured to, when the vehicle approaches the end of a downhill road section while controlling the speed of the vehicle to be maintained at the set speed level v _max :

• Adjusting the applied braking force from the first braking force to a second braking force to accelerate the vehicle to an increased vehicle speed v _sch exceeding the set speed level v _max , the second braking force being applied by at least the regenerative braking system.

It is clear that all the embodiments described for the method aspects of the invention are also applicable to at least one of the aspects of the control arrangement of the invention. Thus, all of the embodiments described for the method aspects of the invention can be carried out by the control arrangement, which also includes a control device, i. H. a device. The control arrangement and its embodiments have advantages that correspond to the advantages mentioned above for the methods and their embodiments.

According to a third aspect of the invention, the above and other objects are achieved by a vehicle having the control arrangement of the second aspect. The vehicle can be, for example, a bus, a truck or a car.

According to a fourth aspect, the invention relates to a computer program with instructions which, when the program is executed by a computer, cause the computer to carry out the method according to the first aspect.

According to a fifth aspect, the invention relates to a computer-readable medium having instructions which, when executed by a computer, cause the computer to carry out the method according to the first aspect.

The features and embodiments of the method, the control arrangement, the vehicle, the computer program or the computer-readable medium mentioned above can be combined in various ways, which enables further advantageous embodiments.

Further advantageous embodiments of the method, the control arrangement, the vehicle, the computer program and the computer-readable medium according to the present invention and further advantages in the embodiments of the present invention result from the detailed description of the embodiments.

Brief description of the drawings

• 1 eine schematische Darstellung eines beispielhaften Fahrzeugs zeigt, in dem Ausführungsformen der vorliegenden Erfindung realisiert werden können;
• 2 ein Flussdiagramm eines Verfahrens zum Betreiben eines elektrischen Motorsystems eines Fahrzeugs gemäß den Ausführungsformen der Erfindung zeigt;
• 3 das Prinzip einer Ausführungsform der Erfindung in einer Fahrsituation veranschaulicht;
• 4 das Prinzip einer weiteren Ausführungsform der Erfindung in einer Fahrsituation veranschaulicht;
• 5 eine Steueranordnung zeigt, in der ein Verfahren nach einer der hier beschriebenen Ausführungsformen durchgeführt werden kann.

Embodiments of the invention are explained in more detail below together with the accompanying drawings, in which similar designations are used for similar parts and where:

• 1 Figure 12 shows a schematic representation of an exemplary vehicle in which embodiments of the present invention may be implemented;
• 2 12 shows a flow diagram of a method for operating an electric motor system of a vehicle according to embodiments of the invention;
• 3 illustrates the principle of an embodiment of the invention in a driving situation;
• 4 illustrates the principle of a further embodiment of the invention in a driving situation;
• 5 shows a control arrangement in which a method according to one of the embodiments described here can be carried out.

Detailed description

As previously discussed, many heavy vehicles today are equipped with a downhill speed control system that controls the speed of the vehicle when going downhill. Conventional hill descent control brakes the vehicle when a braking speed level v _dhsc is reached. The braking speed level v _dhsc for the hill descent control may correspond to the set speed of a cruise control in the vehicle, but mostly corresponds to the set speed of the cruise control plus an offset speed.

Some previously known downhill speed control systems allow a speed increase above the braking speed level v _dhsc at the end of the downhill road section. The brakes can be released before the vehicle reaches the end of the downhill road section and the speed of the vehicle is increased to a level v _sch greater than the braking speed level v _dhsc at the end of the downhill road section. In this way, the vehicle gains kinetic energy in the last part of the downhill road section, which can be used at the end of the downhill road section instead of the energy stored in fuel or in a battery. By avoiding braking in the last part of the downhill road segment, both time and energy are saved, which can result in a greater competitive advantage of such downhill speed control systems.

However, it has been found that the current combination of constant speed braking when descending and then fully releasing the brakes on the final part of the descent may not be entirely energy optimal for vehicles with the ability to regenerate energy during braking.

It is therefore an object of the present invention to provide a method and a control arrangement for controlling a speed of a vehicle with a regenerative braking system so that these problems are at least partially solved.

In 1 , which is used to explain the embodiments presented here, a vehicle 100 and its drive train are shown schematically. The vehicle 100 can e.g. B. be a car, a bus or a truck. The powertrain of the in 1 Vehicle 100 shown includes an electric motor system with at least one electric machine 101, which is designed to drive the drive wheels 111, 112 of the vehicle 100. In the illustrated embodiment, the vehicle 100 includes two drive wheels 111, 112, but it is understood that the vehicle 100 may be equipped with one or more drive wheels. The at least one electrical machine 101 can, as in 1 shown, be connected to a transmission 102 via an input shaft 104 . The vehicle 100 can have a cardan shaft 105 of the transmission 102, which drives the drive wheels 111, 112 via a central transmission 103, for example a conventional differential, and two drive shafts 106, 107 of the vehicle 100. It is understood that the vehicle 100 can be arranged in any known manner, for example without a transmission 102 or a conventional differential, without limiting the scope of the invention.

The at least one electric machine 101 can be located essentially anywhere as long as torque is transmitted to one or more of the wheels 111, 112, for example adjacent to one or more of the wheels, or in any other conventional manner known to those skilled in the art is. The at least one electric machine 101 can be supplied with electric power from a battery system (not shown) that is integrated into the electric motor system of the vehicle 100 .

The vehicle 100 can, as in 1 shown, be a purely electric vehicle that contains only one or more electric machines 101 for driving the drive wheels 111, 112. However, the vehicle 100 may also be a so-called hybrid vehicle and may also include an internal combustion engine (not shown) which may be connected to the transmission 102 in a conventional manner, e.g. B. via a clutch (not shown).

The electric motor system including the electric machine 101 as well as various components of the vehicle's powertrain may be controlled by a vehicle control system via a control assembly 120 . The control arrangement 120 can be distributed over a number of control units which are designed to control different parts of the vehicle 100 . The control arrangement 120 can, for example, comprise a control unit 121 which is used to carry out the method steps of the disclosed invention is directed, as explained below. The control arrangement 120 and/or another control arrangement can also be configured to control any other units/devices/devices of the vehicle 100 . In 1 however, only those units/devices/facilities of the vehicle useful for understanding the present invention are illustrated. The control arrangement 120 is 5 described in more detail.

The vehicle 100 may also include various braking systems (not shown), e.g. B. a conventional service brake system, the z. B. can consist of brake discs with associated brake pads, which are arranged next to each wheel. Heavy vehicles are often equipped with additional braking systems, e.g. B. in the form of conventional retarders 112 and/or other supplemental braking systems such as various types of exhaust braking systems, compression braking systems, electromagnetic braking systems, engine braking and regenerative braking systems.

Based on commands initiated by the driver of the vehicle and/or other control units, the control arrangement (or other suitable control unit) sends control signals to appropriate system modules to retrieve the desired braking force from the desired braking systems. Additional braking systems can also be controlled directly by the driver, e.g. B. via keys or pedals.

In this case, the pedal or the lever can be connected directly to another control unit, which contains information e.g. B. sends to a retarder control unit.

The vehicle 100 may also include one or more sensors 130, e.g. B. at least one radar located at appropriate locations in the vehicle 100.

Furthermore, the vehicle 100 can include a locating system/locating unit 140 . The positioning unit 140 can be based on a satellite navigation system such as the Navigation Signal Timing and Ranging (Navstar), Global Positioning System (GPS), Differential GPS (DGPS), Galeo, GLONASS or the like. The locating unit 140 can therefore include a GPS receiver.

The vehicle 100 may further include at least one communication device 150 configured to communicate with at least one unit 160 external to the vehicle 100, for example at least one communication unit of another vehicle. Accordingly, the at least one communication device 150 may be a vehicle-to-vehicle, V2V, communication device, a vehicle-to-infrastructure, V2I, communication device, a vehicle-to-everything, V2X, communication device, and/or a wireless Be communication device so that communication between the vehicle and the at least one external unit 160 is achieved / provided.

The proposed invention will now be described with reference to a 2 disclosed method 200 for controlling a speed of a vehicle, such as that in 1 disclosed vehicle 100 having a regenerative braking system. The method 200 is carried out by a control arrangement such as that in 1 shown control arrangement 120 performed. The method 200 includes when the vehicle 100 is traveling downhill, automatically applying a first braking force to control the speed of the vehicle to be maintained at a set speed level v _max when that set speed level v _max is reached.

• In Schritt 210 in 2, Anpassen der aufgebrachten Bremskraft von der ersten Bremskraft auf eine zweite Bremskraft, um das Fahrzeug 100 auf eine erhöhte Fahrzeuggeschwindigkeit v_sch zu beschleunigen, die das eingestellte Geschwindigkeitsniveau v_max übersteigt, wobei die zweite Bremskraft zumindest durch das regenerative Bremssystem aufgebracht wird.

The method further includes that when the vehicle 100 approaches the end of a downhill road section while controlling the speed of the vehicle to be maintained at the set speed level v _max :

• In step 210 in 2 , Adjusting the applied braking force from the first braking force to a second braking force to accelerate the vehicle 100 to an increased vehicle speed v _sch that exceeds the set speed level v _max , the second braking force being applied at least by the regenerative braking system.

The present invention can be used in essentially all types of vehicles that have a regenerative braking system, e.g. H. in electric vehicles that use one or more electric machines for propulsion. Examples of such vehicles are battery electric vehicles, hybrid electric vehicles, and plug-in hybrid electric vehicles.

It goes without saying that while driving, the vehicle 100 is subject to various forces consistent with basic principles of physics, particularly Newton's second law of motion, with some forces accelerating the vehicle in the direction of motion and other forces accelerating the vehicle's actual motion counteract. Such forces can B. by the road gradient, the air resistance of the vehicle, internal friction losses in the drive train of the vehicle and by Rei Exercise losses arise between the wheels of the vehicle and the road surface. In order to increase vehicle speed, a force must be applied that is greater than the net force acting on the vehicle in the opposite direction of travel, e.g. B. by providing a traction to accelerate the vehicle. Conversely, a braking force can be applied to increase the forces acting against the current direction of movement, e.g. B. to achieve a lower speed. The braking forces mentioned in this description, ie the first and the second braking force, correspond to the braking force that is applied by the regenerative braking system and/or one or more additional braking systems in the vehicle.

As already explained, the set speed level v _max can be a fixed maximum speed level that the vehicle should not exceed when driving on a downhill road section. This maximum speed v _max can be used to prevent the vehicle from reaching too high a speed, e.g. B. a speed that is higher than the speed limit for the stretch of road or exceeds a speed limit for the vehicle. On a specific road section, the set speed level v _max can therefore be a speed limit that the driver does not want to exceed, e.g. B. to avoid the risk of speeding. The speed level v _max can be adjusted in different ways, which are explained below. In the present invention, the set speed level v _max is automatically maintained when it is reached.

The present invention controls the increase in speed of the vehicle 100 as it approaches the end of a downhill stretch of road to enable energy regeneration. Instead of releasing the applied brakes when approaching the end of the downhill road section in order to increase the speed to an increased vehicle speed v _sch according to previously known methods, a braking force, referred to here as a second braking force, is applied according to the invention during the speed increase by means of at least the regenerative braking force brake system applied. This results in part of the braking energy being recovered by the regenerative braking system. By using the invention, the increase in speed can start at an earlier point in time than the increase in speed according to previously known methods. This means that the speed increase and regenerative braking can take place over a longer period of time. This reduces the peak braking force during the increase in speed and thus reduces the electrical losses. This allows more energy to be recovered by the regenerative braking system in the vehicle. In addition, by reducing the peak braking force during speed increases, the temperature of the electric motor and battery components is lowered, resulting in a reduced risk of motor overheating and more efficient energy recovery.

In addition to method step 210, method 200 may include other optional steps in one embodiment. Thus, in embodiments, method step 210 may be preceded by one or more optional steps 202-208, which are described in 2 are shown in dashed boxes. The optional method steps 202-208 are described further below.

The method 200 and other embodiments of the invention are now described with reference to FIG 3 explained in more detail. 3 12 shows a non-limiting example of a driving scenario in which the method 200 and other embodiments of the invention may be implemented. 3 shows a vehicle like the one in 1 disclosed vehicle 100 traveling at an actual speed v _act that may vary along a route, the topography of the portion of road on which vehicle 100 is traveling is illustrated at the top of the figure.
As previously discussed, vehicle 100 may include a regenerative braking system. The regenerative braking system can be an integral part of the drive train of the vehicle 100, with the electric machine 101 running in generator mode during braking, so that at least part of the braking energy is recovered. According to conventional solutions, the regenerative braking system can include components for recovering or transmitting the decelerated energy from the braking system.

The invention is described here in terms of vehicle positions such as P0, P1, P2, P3, P4, P5 and P6, but those skilled in the art will understand that these positions correspond to respective points in time. In this case, the road segment has a gradient 510 between positions P1 and P5.

As already explained, according to the invention the speed of the vehicle in the downhill road section 510 is automatically controlled in such a way that a set speed level v _max is maintained when this set speed level v _max is reached. In In one example, the vehicle's speed may be controlled in the vehicle's powertrain control system, which executes the logic of method 200 and modifies the driver's manual control of the accelerator and/or brake pedals. In another example, the vehicle 100 may be equipped with cruise control. A goal of speed control is to achieve a predetermined speed. Vehicle speed control in vehicles is often accomplished by two interacting systems, i.e. a speed control system that requests torque from a motor system to maintain a speed v _cc-set set by the speed controller, and a downhill speed control system that prevents the vehicle from over-speeding Develops speed, particularly on downhill road sections, by maintaining a braking speed level v _dhsc .

Thus, in one example, the speed of the vehicle 100 on the downhill road segment 510 may be controlled by a downhill speed control system, and the set speed level v _max may thus correspond to a speed level v _dhsc set in the downhill speed control system.

The set speed level v _max can be set in different ways. It can e.g. B. from the driver or other authorized persons by an input, z. by pressing a button, depressing a brake pedal, or other conventional input. In another example, the set speed level v _max may be set by the driver manually or automatically as an offset to a set speed for an in-vehicle speed control system.

When the vehicle 100 is traveling on the downhill road section 510, the speed of the vehicle is automatically controlled by controlling one or more braking systems in the vehicle 100 so that the set speed level v _max is not exceeded. As already explained, the one or more braking systems can be the regenerative braking system. Optionally, the one or more braking systems can also include at least one additional braking system. The at least one additional braking system can be, as previously referred to 1 explained to act a conventional service brake system, a retarder and / or other additional braking systems such. B. one or more of the various types of exhaust braking system, pressure braking system, electromagnetic braking system, engine braking, etc.

3 12 also shows the actual speed v _act of the vehicle 100, shown as a solid solid line in the lower part of the figure, and a braking force applied by the vehicle's braking system to control the speed of the vehicle 100. FIG. The braking force is shown as a solid line in the middle part of the figure.

As in 3 As shown, the speed of the vehicle traveling between positions P0 and P6 may vary between a first speed level v ₁ , a set speed level v _max and an increased speed level v _sch . The first speed level v ₁ z. B. correspond to a speed level that the vehicle automatically maintains on the road section between the positions P0 and P1. The first speed level v ₁ z. B. correspond to a set speed for the speed control system v _cc-set if the speed of the vehicle is controlled by a speed control system. The set speed level v _max can correspond to a speed level at which the vehicle is braked in order to maintain the speed when driving downhill. The set speed can, for example, correspond to a braking speed v _dhsc that is maintained by a downhill speed control system when the speed of the vehicle is controlled by a downhill speed control system. The increased speed level v _sch can be a speed level that exceeds the set speed level v _max to which the vehicle is allowed to accelerate at the end of the downhill road section in order to gain kinetic energy that can be used instead of the energy stored in fuel or a battery .

The height of the increased speed level v _sch or the difference between the set speed level v _max and the increased speed level v _sch is a factor that decides the amount of kinetic energy that the vehicle can gain at the end of the downhill road section.

In one embodiment, the increased vehicle speed v _sch may be based on various parameters, such as: B. a preset speed level, the set speed level v _max and a period of time, in which the vehicle exceeds the set speed level v _max . In one example, the increased vehicle speed v _sch may be based on a preset speed level that corresponds to a speed level that the vehicle should not exceed or a speed limit that should not be exceeded on the stretch of road the vehicle is traveling on. In one example, the default speed level may be a speed level corresponding to the increased vehicle speed, v _sch , selected by the driver of the vehicle using conventional methods.

In one example, the increased vehicle speed v _sch may be based on the set speed level v _max and may correspond to the set speed level v _max plus an offset value. In one example, the increased vehicle speed _vsch may be based on a period of time that the vehicle exceeds the set speed level _vmax . As a non-limiting example, the vehicle may be traveling on a road where the legal speed limit is 90 km/h. The increased vehicle speed v _sch can be set to 90 km/h plus an offset, which offset can depend on a period of time in which the vehicle speed is allowed to exceed the maximum speed. In another example, the increased vehicle speed v _sch may be based on the set speed level v _max maintained on the downhill road section. The increased vehicle speed v _sch can, for example, correspond to the set speed level v _max plus an offset speed. The offset speed can e.g. B. be set manually by the driver, be determined automatically or correspond to a preset value.

As in 3 As can be seen, the actual speed v _act of the vehicle 100 can be maintained at the first speed level v ₁ when the vehicle is traveling on the road segment between positions P0 and P1. At position P1, the vehicle enters the downhill road segment 510 where the actual speed v _act of the vehicle 100 begins to increase due to gravity. At position P2 the actual speed of the vehicle has reached the set speed level v _max and a first braking force F ₁ is applied to maintain the set speed level v _max in the downhill road section. The first braking force F ₁ can be applied automatically through the control of one or more braking systems in the vehicle 100 . In one example, the set speed level v _max can be maintained, eg by applying the first braking force F ₁ solely with the aid of the regenerative braking system. In another example, in one embodiment, the vehicle speed can be maintained at the set speed level v _max at least partially by at least one additional braking system in the vehicle, eg exclusively by at least one additional braking system or by the regenerative braking system and at least one additional braking system.

As already explained, the previously known solutions for achieving an energy-efficient driving style by utilizing the kinetic energy that the vehicle gains on downhill road sections would automatically maintain the set speed level v _max until the end of the downhill road section is approached. Before reaching the end of the downhill road section, i.e. at position P4 in 3 , the braking system or systems of the vehicle 100 would be released (the braking force F ₀ in the figure means no brakes applied), so that the vehicle speed will increase and at the end of the downhill road section, at the position P5 in 3 , the vehicle speed v _sch would reach that exceeds the set speed level v _max . It should be noted that between position P3 and position P5 in 3 the actual speed of the vehicle 100 and the braking force applied according to the previously known solutions described here are represented by dashed lines.

According to the invention, the vehicle is instead accelerated from the set speed level v _max to the increased vehicle speed v _sch by adjusting the applied braking force from the first braking force F ₁ to a second braking force F ₂ . In addition, according to the invention, the second braking force F ₂ is at least partially applied by the regenerative braking system of the vehicle. As in 3 can be seen, according to the invention, a braking effect corresponding to the second braking force F ₂ is exerted from the brake-actuating position P3 to the position P5, in which the increased vehicle speed v _sch is reached. According to the invention, the speed of the vehicle starts to increase at a position earlier than with previously known solutions, which means that braking takes place over a longer period of time, in which part of the braking energy can be regenerated. Consequently, the energy efficiency of the vehicle is further improved compared to previously known methods.

As already explained, the actual speed v _act of the vehicle 100 increases due to gravity when the vehicle enters the downhill road segment 510, ie at the position P1 in 3 . The acceleration of the vehicle depends on parameters such as the slope of the downhill section of the road and the weight of the vehicle. in the in 3 In the non-limiting example illustrated, the vehicle 100 reaches the set speed level v _max at position P2, ie earlier than at the brake actuation position P3. Thus, between the positions P2 and P3, the applied braking force, which corresponds to the first braking force F ₁ , brakes the vehicle in order to maintain the set speed level v _max . In order for the vehicle to be able to accelerate at the brake actuation position P3, the applied braking force must be reduced from the first braking force F ₁ to the second braking force F ₂ . In one embodiment, the adjustment of the applied braking force can therefore consist of reducing the applied braking force from the first braking force F ₁ to the second braking force F ₂ .

According to the invention, the second braking force F ₂ is applied at least in part by the vehicle's regenerative braking system such that the vehicle is accelerated when the second braking force F ₂ has been applied. In one example, the second braking force P ₂ can be applied by the regenerative braking system and by at least one other braking system in the vehicle. In another example, the second braking force F ₂ may be applied solely by the regenerative braking system.

The amount of braking force to be applied by the regenerative braking system can be determined in a number of ways. In one example, the braking force to be applied by the regenerative braking system may be based on the braking force applied during the speed increase of the vehicle to the increased vehicle speed v _sch , ie the second braking force F ₂ . For example, it can be advantageous to combine the braking force applied by the regenerative braking system with a braking force applied by at least one other braking system in the vehicle, for example in order to optimize energy recovery in the vehicle. In another example, the second braking force F ₂ may exceed the total braking power of the regenerative braking system. Therefore, additional braking power may need to be provided by at least one additional braking system in the vehicle.

In the road section following the downhill road section 510 between the position P5 and the position P6 in 3 the vehicle 100 is no longer accelerated by the gravitational forces acting downhill and begins to lose speed. Here again, the speed of the vehicle can be automatically controlled to maintain the first speed level v ₁ , resulting in the actual speed v _act of the vehicle 100 decreasing to the first speed level v ₁ .

As previously discussed, in one embodiment, the method 200 may include additional optional steps. Thus, in embodiments, method step 210 may be preceded by one or more optional steps 202-208, as in 2 shown. It should be noted that the in 2 illustrated and described here not necessarily in the in 2 must be carried out in the order shown. The steps may be performed in substantially any suitable order so long as the physical requirements and information required to perform each method step are available at the time the step is performed.

In one embodiment, in an optional step 202 in 2 , which precedes step 210 previously described, when adjusting the applied braking force, the second braking force may be determined. The second braking force can be determined in such a way that when it is applied the speed of the vehicle can reach the increased vehicle speed v _sch which exceeds the set speed level v _max at the end of the downhill road section. Such a scenario is in 3 shown where the increased vehicle speed v _sch is reached at the end of the downhill road section, ie at position P5.

If the optional step 202 has been carried out and the second braking force F ₂ has been determined, the applied braking force can be adjusted in step 210 by the second braking force F ₂ determined in step 202 being applied in such a way that the vehicle accelerates to the increased vehicle speed v _sch becomes. In this way, the second braking force can be determined before the applied braking force is adjusted.

The second braking force can be determined in various ways. The second braking force can be determined, for example, at least as a function of the level of the increased vehicle speed v _sch to be achieved by the vehicle and the position at which the increased vehicle speed v _sch is to be reached. In one example, the second braking force can be determined such that the increased vehicle speed v _sch is reached at the end of the downhill road section, when applied in a suitable position to maximize energy savings in the vehicle.

In one embodiment, the second braking force may be determined based at least in part on road grade data of the downhill road segment 510, the curvature of the downhill road segment 510, a weight of the vehicle 100, and/or a drag force acting on the vehicle 100. For example, using Newton's laws of motion, the required braking force required to accelerate the vehicle to the increased vehicle speed v _sch on the downhill road section 510, taking into account the traction and braking forces acting on the vehicle due to the road gradient, des air resistance, the road curvature as well as vehicle characteristics such as vehicle dimensions, a weight of the vehicle, to name just a few.

Information about the properties of the road section in front of the vehicle, such as e.g. B. data on road gradient and road curvature can be easily determined, z. based on map information, GPS information, radar information, camera information, information from another vehicle, information about position and road gradient stored in the vehicle 100 and/or information from traffic systems related to said road segment. The drag on the vehicle can be determined using conventional methods based on the vehicle's internal parameters such as the weight, the speed of the vehicle and the traction provided by the vehicle's electric machine or engine. The vehicle's internal parameters, such as Information such as the weight of the vehicle 100 may be obtained from the vehicle's control system via one or more communication buses connecting the control assembly 120 to various components and controls on the vehicle 100 .

In one embodiment, the second braking force may also be determined based on the traffic situation within the downhill road section 510 such that there is no risk of colliding with or getting too close to other vehicles in front of the vehicle 100 .
In general, information about the current traffic situation on a road section in the vehicle can be provided by one or more sensors 130, e.g. B. one or more cameras, one or more radars, etc. are obtained. Furthermore, such information can be obtained based on information received from at least a second vehicle, e.g. B. by V2V communication, and / or from an infrastructure facility, z. by V2I communication, or based on information obtained from traffic systems related to the road section.

In one example, the second braking force may be determined such that the level of the second braking force is favorable for regeneration with the regenerative braking system. For example, a particular braking system may have a maximum regeneration capacity that corresponds to a particular braking force threshold, the second braking force may be determined to be below that threshold, and the timing at which the second braking force is applied may depend on that determination. In this way, the second braking force can be determined in such a way that the braking energy used by the regenerative braking system is optimized.

In addition, the second braking force can be based on other parameters that are to be optimized, eg energy efficiency, acceptance for the driver of the vehicle, acceptance for other road users and/or driver comfort. In one embodiment, the second braking force may be determined based on, for example, a speed of the vehicle in the downhill road segment 510 and/or the first braking force applied in the downhill road segment. In non-limiting examples, the second braking force may be determined such that a constant acceleration, a constant braking force, or a constant output of the vehicle's regenerative braking system is achieved during a speed increase to the increased vehicle speed v _sch . In addition, the second braking force can be determined in such a way that jerky movements of the vehicle, ie rapid changes in acceleration when the vehicle brakes are released, are avoided.

In one embodiment, the second braking force may also be determined based on heat buildup in the regenerative braking system. For example, the second braking force may be selected such that the temperature of the regenerative braking system or any component thereof does not exceed a temperature threshold. Information about the heat development in the regenerative braking system can e.g. B. can be obtained by monitoring the temperature of the regenerative braking system using suitable sensors.

In one embodiment, the determined second braking force along the downhill lead end road segment 510 change dynamically. For example, if constant acceleration is desired, the second braking force may be selected based on an adaptive algorithm that analyzes how much braking force is required and dynamically adjusts the second braking force based on vehicle speed and road grade.

In one embodiment, in an optional step 204 in 2 , which precedes step 210 described above, determines a brake application position at which the applied braking force is to be adjusted so that the vehicle 100 is accelerated to achieve the increased vehicle speed v _sch exceeding the set speed level v _max . The position may be in the downhill road segment 510 in front of the vehicle 100 . An example of such a brake actuation position P3 is in 3 10 is shown in which the vehicle 100 is on the downhill road segment 510 and is accelerated by its weight and at the same time the second braking force is applied so that the vehicle is accelerated. In one example, the brake application position may be set to a position before the position at which vehicle speed would increase if no braking force were applied during the speed increase, e.g. B. the position P4 in 3 .

In one embodiment, the brake apply position may be determined based at least in part on road grade data of the downhill road segment 510 . For example, the brake application position can be set to a position from which it is calculated that the increased vehicle speed v _sch can be achieved at the end of the downhill road section 510 by applying a braking force that can be provided by the regenerative braking system.

In one embodiment, the brake actuation position may be determined based on the second braking force determined in optional step 202 in 2 was determined. Thus, the brake actuation position can be determined as the position at which the determined second braking force must be applied in order to accelerate the vehicle to the increased vehicle speed v _sch at the end of the downhill road section.

Once optional step 204 has been performed and the brake apply position has been determined, adjustment of applied braking force may occur in step 210 when that position has been reached.

In one embodiment, in an optional step 206 in 2 , which precedes step 210 described above, a regenerative braking force may be applied before the vehicle reaches the set speed level v _max .

If optional step 206 has been performed, the method continues with optional step 208 .

In optional step 208 in 2 the regenerative braking force level can be controlled so that the vehicle reaches the set speed level v _max before or at the position where the applied braking force is adjusted from the first braking force to the second braking force to further accelerate the vehicle.

In the embodiment according to the optional steps 206 and 208, the vehicle can be controlled in such a way that it accelerates immediately after reaching the set speed level v _max when approaching the end of the downhill road section. The regenerative braking force applied before the set speed v _max is reached may be so small that the speed of the vehicle on the downhill road section 510 increases. In one example, the adjustment of the applied braking force from the first braking force to a second braking force to accelerate the vehicle in step 210 in 2 correspond to the application of a second braking force that corresponds to the first braking force that was applied before the vehicle reached the speed level v _max .

4 shows a driving scenario in which the embodiment described above can be implemented. The driving scenario 4 is presented in a manner similar to that in 3 shown driving scenario. So shows 4 a vehicle 100 traveling through a stretch of road with a topography at an actual speed v _act that may vary along a route as described above in FIG 4 shown. As can be seen, the stretch of road between position P1 and position P4 includes in 4 a downhill part.

4 also shows the actual speed v _act of the vehicle 100 when traveling on said road section, shown as a solid solid line in the lower part of the figure, and a braking force generated by the vehicle's braking system vehicle for controlling the speed of the vehicle 100 is applied. The braking force is shown as a solid line in the middle part of the figure.

In a similar way as in 3 described, the speed of the vehicle on the downhill road segment 510 may be automatically controlled to maintain a predetermined level of speed v _max once that predetermined level of speed v _max has been reached.

As in 4 As can be seen, the actual speed v _act of the vehicle 100 can be maintained at a first speed level v ₁ when the vehicle is traveling on the road segment between position P0 and position P1. At position P1, the vehicle enters the downhill road segment 510 where the actual speed v _act of the vehicle 100 begins to increase due to gravity. Here, the speed of the vehicle 100 can be controlled in the downhill road section by applying a regenerative braking force F ₂ before the vehicle reaches the set speed level v _max at the position P2.

As already referred to 3 explained, the previously known solutions for achieving an energy-efficient driving style by utilizing the kinetic energy that the vehicle gains on downhill road sections would automatically maintain the set speed level v _max until the end of the downhill road section is approached. Maintaining the set speed v _max at position P2, at which the set speed v _max was reached, would have required braking power corresponding to the first braking power to be applied at position P2 and maintained up to position P3. At position P3, as one approaches the end of the descent, one or more braking systems of the vehicle 100 according to the prior art solutions would have been released (braking force F ₀ in the figure, which does not show the brakes applied), so that the vehicle speed increases and at the end of the downhill road section and at position P4 the vehicle speed v _sch is reached, which exceeds the set speed level v _max . Note that between position P2 and position P4 in 4 the vehicle speed and the braking force applied are represented by a dashed line according to the previously known solutions described here.

According to the invention, the vehicle at position P2 is instead accelerated from the set speed level v _max to the increased vehicle speed v _sch while maintaining the applied braking force F ₂ . So will in the in 4 illustrated non-limiting example, the applied braking force is adjusted from the first braking force F ₁ to a second braking force F ₂ by the prior to increasing the vehicle speed from the set speed level v _max . applied braking force is maintained

As referring to 3 described, the vehicle 100 is no longer accelerated by the downhill gravitational forces in the section of road between the position P4 and the position P5 and begins to lose speed. Here again, the speed of the vehicle can be automatically controlled to maintain the first speed level v ₁ , resulting in the actual speed v _act of the vehicle 100 decreasing to the first speed level v ₁ . For example, the speed of the vehicle can be reduced by the external forces acting on the vehicle.

According to one aspect of the invention, a control arrangement 120 for controlling a speed of a vehicle 100 is presented. The control arrangement 120 comprises means 121 which are set up to adjust an applied braking force from the first braking force to a second braking force in order to accelerate the vehicle 100 to an increased vehicle speed v _sch which exceeds the set speed level v _max , the second braking force is applied at least by the regenerative braking system.

The control arrangement 120 according to the invention, for example a device or a control device, can be set up to carry out all the method steps described above in the claims and in the embodiments described here. The control arrangement 120 is provided with the advantages described above for the respective embodiment.
The invention also relates to a vehicle 100 with the control arrangement 120.

In 5 There is now shown the control arrangement 600/120, which may correspond to or include the above-mentioned control unit 121, ie the control unit which carries out the method steps of the present invention. The control arrangement 600/120 comprises a computing unit 601, which can essentially be formed by any suitable type of processor or microcomputer, e.g. a circuit for digital signal processing (Digital Signal Processor, DSP), or a circuit with a predetermined specific function (Application Specific Integrated circuit, ASICS). The arithmetic unit 601 is connected to a memory unit 602 which is arranged in the control arrangement 600/120 and which is assigned to the arithmetic unit 601, e.g. B. makes available the stored program code and/or the stored data which the arithmetic unit 601 requires in order to be able to carry out calculations. The arithmetic unit 601 is also set up to store partial or final results of calculations in the memory unit 602 .

In addition, the control arrangement 600/120 is provided with devices 611, 612, 613, 614 for receiving and for transmitting input and output signals. These input and output signals may contain waveforms, pulses or other attributes that can be captured as information by the devices 611, 613 for receiving input signals and converted into signals that can be processed by the computing unit 601. These signals are then made available to the arithmetic unit 601 . Devices 612, 614 for transmitting output signals are set up to convert signals received from processing unit 601 in order to generate output signals, e.g. by modulating the signals, which can be transmitted to other parts and/or systems in vehicle 100.

Each of the connections to the devices for receiving and transmitting input and output signals can be made by one or more cables, a data bus, such as a CAN bus (Controller Area Network Bus), a MOST bus (Media Orientated Systems Transport Bus) or a different bus configuration, or through a wireless connection. A person skilled in the art will understand that the above computer can be formed by the arithmetic unit 601 and the above memory by the storage unit 602.

Control systems in modern vehicles typically include communication bus systems, which consist of one or more communication buses to interconnect a number of electronic control units (ECUs), or controllers, and various components in the vehicle. Such a control system can include a large number of control units, and the responsibility for a specific function can be divided among several control units. Vehicles of the type shown therefore often include significantly more control units than in the 1 and 5 shown, which is well known to those skilled in the art.

In an illustrated embodiment, the invention may be implemented by the control unit 121 mentioned above. However, the invention can also be implemented in whole or in part in one or more other control units already located in the vehicle 100 or in a special control unit for the invention.

Here and in this document, the units are often described as being set up to carry out steps of the method according to the invention. This also includes the units being designed and/or configured to carry out these method steps.

The control unit 121 is in 1 shown as a separate entity. However, these units can be logically separate but physically implemented in the same unit, or they can be both logically and physically co-located. The unit can e.g. B. correspond to groups of instructions, which may be in the form of programming code that is input to and used by a processor/computing unit 601 when the unit is active and/or used to perform its method step.

Those skilled in the art will understand that the embodiments described herein for controlling a motor can also be implemented in a computer program which, when executed on a computer, instructs the computer to carry out the method. The computer program typically consists of a computer program product 603 stored on a non-perishable/non-volatile digital storage medium, with the computer program being incorporated into the computer-readable medium of the computer program product. The computer-readable medium includes a suitable memory, such as. E.g.: ROM (Read-Only Memory), PROM (Programmable Read-Only Memory), EPROM (Erasable PROM), Flash memory, EEPROM (Electrically Erasable PROM), a hard disk unit, etc.
The invention is not limited to the embodiments described above. Rather, the invention relates to and encompasses all of the various embodiments that fall within the scope of the independent claims.

Claims (17)

A method (200) performed by a control arrangement for controlling a speed of a vehicle (100), the vehicle (100) including a regenerative braking system, the method including automatically applying a first braking force when traveling downhill to to control the speed of the vehicle so that it is on a set speed level, v _max , is maintained when said set speed level, V _max , is reached, the method (200) further comprising when the vehicle (100) approaches the end of a downhill road section (510) while the speed of the vehicle is controlled to be maintained at the set speed level, V _max : adjusting (210) the applied braking force from the first braking force to a second braking force to accelerate the vehicle (100) to an increased vehicle speed, v _sch that exceeds the set speed level, V _max , with the second braking force being applied by at least the regenerative braking system. Method (200) according to claim 1 , wherein adjusting (210) the applied braking force comprises reducing the applied braking force from the first braking force to the second braking force. Method (200) according to any one of Claims 1 until 2 , wherein the second braking force is applied solely by the regenerative braking system. Method (200) according to any one of Claims 1 until 3 , wherein the increased vehicle speed, v _sch , exceeding the set speed level, V _max , is based on at least one of: a preset speed level, the set speed level, V _max , and/or a period of time that the vehicle has exceeded the set speed level , V _max , exceeds. Method (200) according to any one of Claims 1 until 4 , further comprising, if the applied braking force is adjusted: determining (202) the second braking force which, when applied, will enable the vehicle (100) to achieve the increased vehicle speed, v _sch , exceeding the adjusted speed level, V _max when the vehicle (100) reaches the end of the downhill road section (510), wherein adjusting (210) the applied braking force further comprises applying the determined second braking force such that the vehicle (100) accelerates to the increased vehicle speed v _sch becomes. Method (200) according to claim 5 , wherein determining (202) the second braking force is based at least in part on one or more of the following: road grade data of the downhill road section (510), a curvature of the downhill road section (510), a weight of the vehicle (100), a weight on the Vehicle (100) acting air resistance and / or a traffic situation within the downhill road section (510). Method (200) according to claim 6 wherein determining (202) the second braking force is further based on at least one of: a speed of the vehicle on the downhill road segment (510), the first braking force applied on the downhill road segment (510), and/or heat generation in the regenerative braking system. Method (200) according to any one of Claims 1 until 7 wherein the determined second braking force may change dynamically along the downhill road segment (510). Method (200) according to any one of Claims 1 until 8th , further comprising: determining (204) a position in the downhill road segment (510) in front of the vehicle (100) at which the applied braking force is to be adjusted in order to accelerate the vehicle (100) by the increased vehicle speed, v _sch , exceeding the set speed level, v _max , and adjusting (210) the applied braking force upon reaching said position. Method (200) according to claim 9 wherein determining (204) the position is based at least in part on road grade data of the downhill road segment (510). Method (200) according to any one of claims 9 until 10 wherein determining (240) said position is based on the determined second braking force. Method (200) according to any one of Claims 1 until 11 , further comprising: applying (206) a regenerative braking force before the vehicle reaches the set speed level, v _max ; and controlling (208) a level of regenerative braking force such that the vehicle reaches the set speed level, v _max , before or at the position at which the applied braking force is adjusted from the first braking force to the second braking force to continue the vehicle to accelerate. Procedure according to one of Claims 1 until 12 , wherein prior to adjusting the applied braking force to accelerate the vehicle to an increased vehicle speed, v _sch , which is the adjusted Speed level, v _max , exceeds the vehicle speed is at least partially maintained at the set speed level, v _max , with the help of the regenerative braking system. Control arrangement (120) for controlling a speed of a vehicle (100), the vehicle (100) comprising a regenerative braking system, the control arrangement (120) being configured for, when the vehicle (100) travels downhill, automatically applying a first braking force, to control the speed of the vehicle to be maintained at a set speed level, v _max , when that set speed level, v _max , is reached, wherein the control arrangement (120) is further configured to, when the vehicle (100 ) approaches the end of a downhill road section (510) while controlling the vehicle's speed to maintain it at the set speed level, v _max : adjusting (210) the applied braking force from the first braking force to a second braking force, to accelerate the vehicle (100) to an increased vehicle speed, v _sch , that exceeds the set speed level, v _max , the second braking force being applied by at least the regenerative braking system. Vehicle (100) with a control arrangement (120). Claim 14 . A computer program comprising instructions which, when the program is executed by a computer, cause the computer to perform the method (200) according to any one of Claims 1 until 13 to execute. A computer-readable medium containing instructions that, when executed by a computer, cause the computer to perform the method (200) of any one of Claims 1 until 13 to execute.

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