Method for controlling an electric drive, control unit and vehicle

Abstract

The invention relates to a method (100) for controlling an electric drive (20) configured for generating a torque (M) on a wheel (30) of an axle (31) of a vehicle (10), the method comprising the following steps: - receiving a deceleration request signal (V1, V2, V3, V4) (S1); - evaluating the deceleration request signal (V1, V2, V3, V4) and classifying it into a classified deceleration request signal (V K ) (S2); - determining a gradient limit (G L1 , G L2 ) of a torque gradient (G1, G2) of the electric drive (10) depending on the classified deceleration request signal (V K ) (S3a, S3b); and - controlling the electric drive (20) by a drive control signal (A) to generate a negative torque (M) on the wheel (30) of the axle (31) depending on the determined gradient limit (G L1 , G L2 ) (S4a, S4b). The invention also relates to a control unit (60) for a vehicle (10) and to a vehicle (10), in particular a commercial vehicle, for implementing the method.

Description

Technical Field

[0001] This invention relates to a method for controlling an electric drive configured to generate torque on the wheels of a vehicle axle. The invention also relates to a control unit for implementing the method in a vehicle, and to a vehicle, particularly a commercial vehicle. Background Technology

[0002] US2018 / 0154777A1 discloses a braking control method and apparatus thereof, wherein the control unit of the apparatus is configured to receive driving environment information from at least one sensor and assess emergency braking needs. The control unit is also configured to activate regenerative braking and friction braking functions to decelerate the vehicle. Furthermore, the control unit is configured to monitor the rotational speed of at least one wheel of the vehicle and adjust regenerative braking and friction braking based on the monitored rotational speed. Summary of the Invention

[0003] According to the features of independent claim 1, a method for controlling an electric drive is proposed, wherein the electric drive is configured to generate torque on the wheels of a vehicle axle, the method comprising the following steps: - Receive deceleration request signal; - Evaluate and classify the deceleration request signal to obtain the classified deceleration request signal; - Based on the classified deceleration request signal, determine the gradient limit of the torque gradient of the electric drive; and - The electric drive is controlled by a drive control signal to generate negative torque on the wheels of the axle according to the determined gradient limit.

[0004] The proposed method allows for dynamic, flexible, and situational adjustment of torque generation at the wheels of the axle. It also enables the deceleration effect of the deceleration request signal to better adapt to current driving conditions. For example, the deceleration effect can be influenced to improve braking of the vehicle's protective components or to shorten the vehicle's braking distance, with each requirement considered to varying degrees depending on the situation.

[0005] The electric actuator is configured to generate torque on the wheels of a vehicle axle. This torque can be generated by the electric actuator on one or more wheels of one or more axles, allowing the electric actuator to be designed, for example, as an independent wheel actuator or a central actuator for multiple axles. Alternatively, a shared electric actuator can be provided for multiple wheels of a single axle, resulting in one electric actuator per axle. The electric actuator can be configured to generate both positive and negative torque on at least one wheel, where positive torque enables acceleration and negative torque enables deceleration. For controlled acceleration or deceleration, a drive control signal is provided, which is converted into torque generation by the electric actuator. The drive control signal can be generated, for example, by a control unit that can convert an acceleration request signal or deceleration request signal input at the control unit's input into a corresponding drive control signal output at the control unit's output. If the vehicle has multiple electric actuators for the wheels of an axle, the control unit can be configured to coordinate the drive control signals of the multiple electric actuators with each other to achieve coordinated acceleration or deceleration. For example, drive control signals can be provided to the electric actuators based on certain driving conditions (such as cornering), resulting in different torques on the individual wheels of the axle.

[0006] The vehicle can be, in particular, a commercial vehicle. For example, a commercial vehicle can be a tractor, a trailer, or a combination of both. The aforementioned advantages of this method show significant optimization potential, especially for commercial vehicles, because they typically have a larger gross vehicle weight than passenger cars, resulting in greater loads on vehicle components. Therefore, it is more advantageous to dynamically and flexibly prioritize extending the lifespan of vehicle transmission components or improving deceleration performance. A particularly advantageous application scenario for this method is a combination of a tractor and a trailer, where the tractor has an electric actuator for generating torque on the wheels of its axles, and the trailer is connected to the tractor, having an electric actuator for generating torque on the wheels of its axles. This allows the corresponding deceleration effects of the tractor and trailer to be coordinated, thereby reliably preventing, for example, the trailer from colliding with the tractor due to weaker deceleration. For example, it can be envisioned that a shared drive control signal is transmitted to the electric drives of both the tractor and the trailer, or that separate drive control signals are generated for the electric drives of the tractor and the trailer respectively, using a classified deceleration request signal and a determined gradient limit, so as to consider different vehicle characteristics separately. However, in principle, it is also possible, for example, to apply this method to vehicle combinations by combining a tractor with a combustion-driven drive with a trailer with an electric drive, or by combining a tractor with an electric drive with a trailer that is not driven. According to one possible design, the trailer can be designed as a saddle trailer, and the tractor can be designed as a saddle tractor.

[0007] The deceleration request signal can be generated based on the current driving situation. For example, it can be converted into a deceleration request signal from the driver's braking intention or a dangerous situation identified by the vehicle. The signal strength, signal curve, or signal type of the deceleration request signal can vary depending on the driving situation. Therefore, the deceleration request signal can be evaluated and classified using signal characteristics (e.g., also using the signal curve), for example, using the aforementioned control unit, so that the classified deceleration request signal can, for example, infer a certain driving situation.

[0008] Torque generated at the wheels of a vehicle axle by an electric actuator can be determined based on a torque gradient, for example, set in the control technology. The torque gradient can be understood as the rate of change of torque over time, such as the slope of the torque curve, or more simply, the rate of increase of torque. A higher torque gradient can result in a greater deceleration effect, but due to the design characteristics and operating mode of the electric actuator, it also places a greater load on the actuator components compared to a lower torque gradient. Therefore, it is technically advantageous to limit the torque gradient of the electric actuator to protect its components, particularly preventing damage caused by excessively high torque gradients. For this purpose, a gradient limit can be defined, for example, and stored in the control unit. This gradient limit is equivalent to a limit on the rate of change of torque over time. In other words, from the point where the gradient limit is reached, a faster increase in torque can be selectively avoided. In principle, it is conceivable that this gradient limit could be set as a fixed characteristic value depending on the type of electric actuator. However, this paper proposes determining the gradient limit of the electric actuator's torque gradient based on a classified deceleration request signal. Therefore, the dynamic determination of the gradient limit can be based on the current driving conditions and the resulting specific deceleration request signal. The advantage of this approach is that control techniques can be employed to strike a balance between the desired deceleration effect and the required component protection, depending on the situation. The determination of the gradient limit can, for example, involve selecting a specific gradient limit from a plurality of predefined gradient limits, where "plural" can be, for example, formed by two or more gradient limits. Alternatively or additionally, the calculation of a specific gradient limit can be performed using a predefined algorithm or calculation pattern based on the classified deceleration request signal. For example, it is also conceivable to interpolate among predefined gradient limits to allow for the selective determination of individual gradient limits.

[0009] According to one embodiment, the vehicle may have a brake controller for controlling the vehicle's braking function, and the reception, evaluation, and classification of deceleration request signals into categorized deceleration request signals can be performed by this brake controller. The brake controller may be the aforementioned control unit or part of it, configured to convert deceleration request signals input to the brake controller's input into corresponding drive control signals. Therefore, the above method steps can be performed without an additional control unit, and the method can be implemented using existing control components of the vehicle. The vehicle's brake controller is typically designed to receive deceleration request signals; therefore, only the deceleration request signals need to be evaluated and classified to determine appropriate gradient limits, enabling the implementation of the method using the brake controller.

[0010] According to another design of the above-described embodiment, the vehicle may also have a drive controller for controlling the electric drive, wherein: - The gradient limit of the electric drive's torque gradient is determined based on the classified deceleration request signal via the brake controller and / or drive controller; and - The electric drive is controlled by the drive controller using drive control signals to generate negative torque according to the determined gradient limit.

[0011] Therefore, according to the first variation, the gradient limit can be determined by the brake controller and transmitted to the drive controller. In the brake controller, deceleration request signals can be classified according to the above embodiment, so that further processing can be technically advantageously performed directly in the brake controller by assigning gradient limits to the classified deceleration request signals. According to the second variation, the determination of the gradient limit can be performed in the drive controller. The characteristics of one or more electric drives of the vehicle can be accurately stored in the drive controller, so that the determination of the gradient limit can be technically advantageously performed within the drive controller. By combining the first and second variations, according to the third variation, the gradient limit can be determined in both the brake controller and the drive controller. For example, the steps for determining the gradient limit can be distributed between the brake controller and the drive controller. For example, the gradient limit can be determined separately in the brake controller and the drive controller, and these determined limits can be compared and / or combined into a common gradient limit to reliably and / or accurately determine the gradient limit.

[0012] The drive controller and brake controller can together constitute a single control unit of the vehicle, such as the control unit described above. The drive controller and brake controller can be interconnected via signaling technologies, such as wired or wireless, to enable, for example, the transmission of classified deceleration request signals and / or gradient limits from the brake controller to the drive controller. In principle, according to other embodiments, it is also conceivable, for example, to perform the method using only the drive controller or only the brake controller. Furthermore, it is feasible, for example, to incorporate sensing signals or predictive information from other controllers of the vehicle into the evaluation and classification of the deceleration request signal. For example, the vehicle may have vehicle environment sensors whose sensor signals are evaluated by other controllers for hazardous conditions of the vehicle, and based on this, can aid in the classification of the deceleration request signal, for example, by transmitting the evaluation results to the brake controller and / or drive controller. The evaluation results can be used, for example, to perform a reasonableness check on the classified deceleration request signal, or directly for classification.

[0013] According to one implementation, when evaluating and classifying a deceleration request signal into a classified deceleration request signal, it can be determined whether a potential emergency braking situation exists. This provides a clear criterion for determining a gradient limit, which can prioritize deceleration effects by the negative torque generated on the wheels of the axle, for example, for the protection of components of an electric actuator. An emergency braking situation can be, for example, a driving situation requiring maximum deceleration, such as to avoid an anticipated collision. For example, a binary classification can be performed, according to which, as a classification result, either a potential emergency braking situation exists or a potential emergency braking situation does not exist; or, according to the binary classification, as a classification result, either an emergency braking situation exists or a potential emergency braking situation does not exist. Here, "no potential emergency braking situation" or "no emergency braking situation" can, for example, refer to a normal braking situation, in which case it is not necessary to increase or maximize the deceleration effect beyond the usual level of the standard deceleration effect in normal operation. With binary classification, this method can be very easy to implement because it is classified according to only two states, and can be selected from, for example, two gradient limits based on the classified state. In particular, with this binary classification method, the limit can usually be selected based on the component load, except for a very few emergency situations. For example, it could be stipulated that a separate gradient limit is determined only in potential emergency braking situations, and this gradient limit differs from the standard gradient limit set for normal operation. For instance, this standard gradient limit could be stored in the aforementioned drive controller, and in potential emergency braking situations, the brake controller could set a different gradient limit, or a request to determine a different gradient limit could be transmitted to the drive controller. It is also conceivable to define further classification results related to potential emergency braking situations, such as based on the state of "no emergency braking situation," "emergency braking situation that may cause property damage," or "emergency braking situation that may cause personal injury." This allows for differentiated classification and different trade-offs between component protection and the expected deceleration effect.

[0014] According to one implementation, the evaluation and classification of deceleration request signals can be performed based on hazard levels with different hazard potential values. This allows for improved, finer adjustment of the desired deceleration effect and reduced component load. By classifying deceleration request signals according to hazard levels with different hazard potential values, torque delivery can be individually optimized, and differentiated vehicle responses suitable for different situations can be achieved. According to one design, the hazard potential value can be a risk indicator, which includes, for example, the potential probability of an accident and / or the expected degree of damage, and can be calculated as a representative indicator and signaled. Classifying deceleration request signals according to hazard levels with different hazard potential values ​​allows for stepwise classification of deceleration request signals, the characteristics of which can be used to infer driving situations with different hazard levels. According to a simplified example, where classification is based on the vehicle's expected collision risk, the hazard levels might be as follows: - No risk of collision, for example, when braking due to approaching a speed-limited section; - Low risk of collision, such as when braking is attempted due to visible traffic congestion in the distance; - Moderate collision risk, such as braking intent due to traffic congestion after a curve; and / or - High collision risk, such as when braking is intended due to an impending accident in front of the vehicle.

[0015] Based on other examples, hazard levels can also be associated with the following different categories: - Vehicle defects, such as engine failure or lighting defects; - Vehicle environment, such as urban traffic or highways; or - Road conditions, such as uneven, wet, or icy surfaces. Furthermore, it is conceivable to further subdivide the emergency braking situations described above into different levels of danger, for example, based on the expected property damage or personal injury.

[0016] According to one embodiment, a gradient limit can be determined based on a classified deceleration request signal, such that the gradient limit is designed to ensure or extend the minimum service life of the transmission components of the electric drive. This allows for a deceleration effect that protects the components, thereby extending the achievable operating time of the transmission components of the electric drive. The minimum service life can, for example, be a predetermined operating time of the transmission components, where extending the minimum service life can generally be considered as extending the service life of the transmission components beyond the minimum service life. For example, for a classified deceleration request signal indicating a low hazard level or no emergency braking situation, a stronger, component-optimized limit can be applied to the torque gradient, rather than a weaker, less restrictive limit optimized for deceleration. In other words, the gradient limit for ensuring or extending the minimum service life of the transmission components can be lower than the gradient limit for improving deceleration effects, which will be described below. Using a lower gradient limit allows for a lower rate of change of torque over time; thus, in short, using a gradient limit for ensuring or extending the minimum service life of the transmission components allows for slower torque changes than using a gradient limit for improving deceleration effects. The minimum service life of the drive components of an electric drive can be advantageously ensured or extended using low gradient limits. These drive components may include, for example, bearings in a motor and / or gearbox, gear sets with teeth, and the housing of the electric drive. Furthermore, it avoids adverse effects on the strength of the shaft components. Additionally, low gradient limits can also ensure or extend the minimum service life of the power semiconductors in the inverter of the electric drive. According to one example of this embodiment, the gradient limit suitable for ensuring or extending the minimum service life of the drive components of the electric drive may be, for example, between 5,000 Nm / s and 50,000 Nm / s, such as approximately 10,000 Nm / s. According to one design of this embodiment, the gradient limit can be determined by designing it to maximize the service life of the drive components of the electric drive. This allows for optimization of component protection within technically feasible limits.

[0017] According to one implementation, the gradient limit can be determined based on a classified deceleration request signal in a way that the gradient limit is designed to enhance deceleration effectiveness. This allows for an appropriate deceleration response, enabling a shorter braking distance, for example, in driving situations with high potential danger. In this case, reduced service life or potential damage to transmission components can be intentionally allowed, so as to address the urgency of the driving situation, for example, by enhancing deceleration effectiveness. For example, for a classified deceleration request signal representing a high level of danger or an emergency braking situation, a weaker, less restrictive limit optimized for deceleration can be applied to the torque gradient, rather than a stronger restriction optimized for components. In other words, the gradient limit for improving deceleration effectiveness can be higher than the gradient limit previously described for ensuring or extending the minimum service life of transmission components. A higher gradient limit allows for a higher rate of torque change over time; therefore, in short, a gradient limit for improving deceleration effectiveness allows for faster torque changes than a gradient limit for ensuring or extending the minimum service life of transmission components. According to one example of this embodiment, the gradient limit suitable for ensuring or extending the minimum service life of the transmission components of the electric drive can, for example, be between 150,000 Nm / s and 250,000 Nm / s, particularly about 200,000 Nm / s. According to one design of this embodiment, the gradient limit can be determined by designing it to maximize the deceleration effect. This allows for optimization of the deceleration effect within technically feasible limits, for example, up to the maximum load capacity of the transmission components of the electric drive. For example, the gradient limit suitable for maximizing the deceleration effect can be determined through load testing.

[0018] According to one embodiment, a gradient limit can be determined based on a classified deceleration request signal, such that the gradient limit lies between a gradient limit for ensuring or extending the minimum service life of the transmission components of the electric drive and a gradient limit for enhancing the deceleration effect. Specifically, the gradient limit can lie between a gradient limit for maximizing the service life of the transmission components of the electric drive and a gradient limit for maximizing the deceleration effect. Therefore, a gradient limit between two defined gradient limits can also be determined (e.g., selected or calculated). This allows for improved fine-tuning of the desired deceleration effect and reduction of component load. Furthermore, it allows for individual optimization of torque delivery and differentiated, situation-appropriate vehicle responses. The gradient limit between the gradient limit for ensuring or extending the minimum service life of the transmission components of the electric drive and the gradient limit for enhancing the deceleration effect can, for example, be determined in response to a progressively classified deceleration request signal, for example, selected based on a classified hazard level with different potential hazard values. Furthermore, the gradient limit can be calculated as an intermediate value, for example, based on a predefined standard or by interpolation between two predefined gradient limits.

[0019] According to one embodiment, brake pedal signals, accelerator pedal signals, driver monitoring signals, and / or vehicle status information can be incorporated into the evaluation and classification of deceleration request signals. This enables differentiated evaluation and accurate, reliable classification of deceleration request signals. The aforementioned signals and information can serve as triggering factors, influencing factors, and / or indications of deceleration demand or intention. Incorporating one of the aforementioned signals or information can be achieved, for example, by comparing with reference signals or information, by setting definition conditions for the signals or information used for classification, or by incorporating them into a predetermined calculation method. A deceleration intention can be indicated, for example, by reducing the load on the accelerator pedal and / or by applying pressure to the brake pedal, and can be identified by changes in the accelerator and brake pedal signals associated with the reduction or application of load, wherein instantaneous or dynamic changes in the brake pedal signal and / or accelerator pedal signal can be incorporated into the evaluation and classification of the deceleration request signal. Driver monitoring signals can be generated, for example, by means of a sensing driver monitoring system configured to identify critical driver states, such as those caused by unexpected driver health effects, and for this purpose may include, for example, an optical monitoring unit connected to an image processing unit. Driver monitoring signals can, for example, indicate potential emergency braking situations or hazard levels with high potential danger values, and deceleration request signals can be classified accordingly. Vehicle status information can be generated, for example, by a sensing and / or predictive vehicle monitoring system configured to identify critical vehicle states, such as those resulting from vehicle malfunctions, or to perform predictive collision identification or trajectory prediction. Vehicle status information can also be related to current vehicle characteristics, such as the vehicle's gross vehicle weight or speed, which are known to or can be communicated to the control unit used to implement the method. Using this vehicle status information, for example, potential emergency braking situations or hazard levels with high potential danger values ​​can be indicated, and deceleration request signals can be classified accordingly. Brake pedal signals, accelerator pedal signals, driver monitoring signals, and / or vehicle status information can also be jointly evaluated in combinations or sub-combinations to provide classified deceleration request signals. For example, it is also possible to perform a plausibility check on the classified deceleration request signals using one or more of the aforementioned signals or information to improve the reliability of the classification. In this regard, when classifying deceleration request signals, it is feasible to selectively query other sensor data from the driver monitoring system or vehicle monitoring system to verify the classification results or to support the classification results with other information about a certain vehicle condition.

[0020] According to one embodiment, the evaluation and classification of deceleration request signals can be performed using the signal curves of the brake pedal signal and / or the accelerator pedal signal. This simplifies the evaluation and classification of deceleration request signals, allowing for the reliable identification of emergency braking situations or different levels of danger, for example, using one or more signal curves. The signal curves may correspond, for example, to the time-varying curves of the accelerator pedal signal or the brake pedal signal, and these two time-varying curves can be combined for evaluation and classification. For evaluation and classification, certain characteristics or patterns, such as gradients, extreme points, or inflection points, of one or more signal curves can be examined. For example, negative gradients of the accelerator pedal signal and / or positive gradients of the brake pedal signal can be identified and evaluated, where the gradient defines the rate of change of signal intensity over time. When evaluating multiple signal curves jointly, the switching time between unloading the accelerator pedal and loading the brake pedal can also be considered for evaluation. It is conceivable, in principle, that the instantaneous absolute values ​​of the brake pedal signal and / or the accelerator pedal signal can be considered alternatively or additionally. However, time-domain signal curves or the relative changes of signals over time may be more convincing, and thus beneficial for differentiating deceleration request signals.

[0021] According to one embodiment, based on the classified deceleration request signal, in addition to controlling the electric actuators of the wheels on the axle via drive control signals, the vehicle's friction braking device can also be controlled. This allows for additional deceleration through the vehicle's friction braking device. Furthermore, the electric actuators and the vehicle's friction braking device can be individually coordinated in terms of torque generation, for example, by individually allocating deceleration requests to optimize the deceleration effect. For example, the electric actuators and friction braking devices can be controlled separately based on the classified deceleration request signal, thereby ensuring or extending the minimum service life of the transmission components of the electric actuators and / or the minimum service life of the braking components of the friction braking device; or the maximum deceleration effect can be achieved by increasing the gradient limit and maximizing the utilization of the electric actuators and the friction braking device. For example, the control unit described above can be configured to provide drive control signals and control the friction braking device, wherein the control unit can advantageously be constituted by the aforementioned brake controller configured to control the braking function of the vehicle, or may have the aforementioned brake controller. The aforementioned signals and information regarding brake pedal signals, accelerator pedal signals, driver monitoring signals, and / or vehicle status information can not only be advantageously used for evaluating and classifying deceleration request signals, but also, for example, for determining appropriate control schemes to coordinately control the electric actuator and friction braking devices. For instance, the state of the vehicle's friction braking devices can be considered when determining the control scheme. For example, to achieve a higher or maximized deceleration effect, if the friction braking devices, for example, have been idle for a long time, such as when the friction pairs are in a non-operating state and therefore the friction brakes have not been fully broken in, a greater load can be applied to the electric actuator with a high gradient limit.

[0022] The present invention also relates to a control unit for a vehicle, the control unit being used to implement the method according to one of the above features, wherein the control unit is configured to: receive, evaluate, and classify a deceleration request signal into a classified deceleration request signal; determine a gradient limit for the torque gradient of the electric actuator based on the classified deceleration request signal; and provide a drive control signal for the electric actuator to generate negative torque at the wheels of the axle according to the determined gradient limit. Using such a control unit, the aforementioned advantages can also be achieved, namely, appropriate adjustment of the torque generation at the wheels of the axle as needed, and obtaining a deceleration effect more adapted to the current driving situation. The control unit can, for example, be configured to generate a drive control signal, wherein the control unit can convert an acceleration request signal or a deceleration request signal input at the input terminal of the control unit into a corresponding drive control signal. If the vehicle has multiple electric actuators for the wheels of the axle, the control unit can be configured to coordinate the drive control signals of the multiple electric actuators with each other, thereby achieving a coordinated acceleration or deceleration effect. The control unit can be configured to receive deceleration request signals, for example, by connecting to a vehicle system configured to generate deceleration request signals using signaling technology, such as an accelerator pedal device, a brake pedal device, a driver monitoring system, and / or a vehicle monitoring system. The control unit can be configured to evaluate and classify the deceleration request signals using signal characteristics and / or signal curves. The control unit can, for example, be configured to incorporate brake pedal signals, accelerator pedal signals, driver monitoring signals, and / or vehicle state information into the evaluation and classification of the deceleration request signals. According to one embodiment, the control unit may consist of a single controller, such as a brake controller. According to other embodiments, it is conceivable that the control unit has multiple controllers, such as two or more controllers. For example, the control unit may have a brake controller and a drive controller. The brake controller and drive controller may be interconnected using signaling technology. Furthermore, the control unit may also have other controllers, or connect to other controllers using signaling technology, which may, for example, sense or predictively determine the potential hazard value of a driving situation, thereby evaluating and classifying the deceleration request signals according to the hazard level of the different potential hazard values.

[0023] The present invention also relates to a vehicle, particularly a commercial vehicle, for implementing the method according to one of the above features, wherein the vehicle has an electric drive configured to generate torque on the wheels of the vehicle's axles, a mechanism for generating a deceleration request signal, and a control unit according to one of the above features. The mechanism for generating the deceleration request signal may be, for example, an accelerator pedal device, a brake pedal device, a driver monitoring system, and / or a vehicle monitoring system. Using such a vehicle, the aforementioned advantages can also be achieved, namely, the appropriate adjustment of torque generation on the wheels of the axles as needed, and a deceleration effect more adapted to the current driving conditions. These advantages show significant optimization potential, particularly for commercial vehicles, because commercial vehicles typically have a larger gross vehicle weight than passenger cars, resulting in greater loads on vehicle components. Therefore, it is more advantageous to dynamically and flexibly prioritize extending the service life of vehicle transmission components or improving deceleration performance.

[0024] According to one embodiment, a vehicle may have multiple axles, each axle having wheels that can be driven by an electric drive. For example, a vehicle may have two or more axles with wheels that can be driven by an electric drive. The electric drive may, for example, be designed as a central drive for the wheels on two or more axles. However, it is also conceivable in principle to design the electric drive as an independent wheel drive or a common electric drive for multiple wheels on an axle. The electric drive may be configured to generate positive and negative torques on at least one wheel according to a drive control signal, wherein the positive torque enables acceleration and the negative torque enables deceleration.

[0025] According to one embodiment, the vehicle can be designed as a tractor, a trailer, or a combination of vehicles with a tractor and a trailer. In this case, the tractor and / or trailer can have electric drives configured to generate torque at the wheels of the vehicle's axles. According to an advantageous design, both the tractor and trailer in the vehicle combination can have such electric drives, which can be controlled by drive control signals according to the aforementioned characteristics. This allows the corresponding deceleration effects of the tractor and trailer to be coordinated with each other, thereby reliably preventing, for example, the trailer from colliding with the tractor due to weaker deceleration on the trailer. Here, for example, it is conceivable that a common drive control signal can be transmitted to the electric drives of the tractor and trailer, or that separate drive control signals can be generated for the electric drives of the tractor and trailer using classified deceleration request signals and defined gradient limits, so that, for example, different vehicle characteristics can be considered separately. However, in principle, it is also feasible to provide a vehicle combination with a tractor and a trailer, the tractor having another drive, such as a combustion drive, and the trailer having an electric drive; or to provide a vehicle combination with a tractor and an undriven trailer, the tractor having an electric drive. According to one possible design, the trailer can be designed as a saddle trailer, and the tractor can be designed as a saddle tractor. Attached Figure Description

[0026] This invention allows for various implementations, which will be described in detail below with reference to embodiments and accompanying drawings. Indicatively: Figure 1 This is a flowchart of a method for controlling an electric drive according to one embodiment; Figure 2 Exemplary curves showing torque variation over time based on two different torque gradients are shown. Figure 3 Exemplary curves showing the changes in accelerator pedal signal and brake pedal signal over time under two different driving conditions are shown. Figure 4 A control unit for a vehicle is shown according to one embodiment; Figure 5 A vehicle with a control unit is shown according to one embodiment; Figure 6 A vehicle with a control unit is shown according to another embodiment. Detailed Implementation

[0027] Figure 1 A simplified and schematic flowchart of a method 100 for controlling an electric drive 20 configured for use in a vehicle 10 (e.g., in...) is shown. Figure 5 For example, on the wheel 30 of the axle 31 (shown in the diagram), an axle 31 is subjected to an axle 31. Figure 2The torque M is shown in the figure. In the first step S1 of the method 100, the torque M is received, for example, in Figure 4 The deceleration request signals V1, V2, V3, and V4 are shown in the figure. In the second step S2 of the method 100, the deceleration request signals V1, V2, V3, and V4 are evaluated and classified into classified deceleration request signals V. K Subsequently, based on the classified deceleration request signal V K Determine the gradient limits G of the torque gradients G1 and G2 of the electric drive 20. L1 G L2 (See also) Figure 4 ).according to Figure 1 The embodiment shown serves as the classified deceleration request signal V. K For example, a binary classification can be defined, with the classification result being either "emergency braking situation" or "non-emergency braking situation". Figure 1 In this context, the binary classification is represented by condition C1, which takes the form of a system query regarding an emergency braking situation. If the response is positive (Y), the process proceeds to the third step S3b of method 100; if the response is negative (N), it proceeds to the third step S3a of method 100. Step S3a of method 100 can correspond to determining the first gradient limit G. L1 Step S3b of method 100 can correspond to determining the second gradient limit G. L2 In the subsequent process, according to the fourth step S4a or the fourth step S4b of method 100, the electric driver 20 is controlled by the drive control signal A to adjust the speed according to the determined gradient limit G. L1 G L2 A negative torque M is generated on the wheel 30 of the vehicle axle 31. At the end of method E, method 100 initially terminates, but can restart by receiving another deceleration request signal V1, V2, V3, V4. Using the proposed method 100, the torque generated on the wheel 30 of the vehicle axle 31 can be flexibly adjusted to adapt to driving conditions and the deceleration demands arising from those conditions, thereby optimizing the deceleration effect W as needed. The deceleration effect W can be influenced, for example, to facilitate deceleration of the vehicle 10 in a way that protects components, or to enhance the braking effect of the vehicle 10; depending on the specific circumstances, both requirements can be considered to varying degrees. Figure 1 In the embodiments described, binary classification can be performed on deceleration request signals V1, V2, V3, and V4 to generate a classified deceleration request signal V. K According to other implementations, for example, it is also possible to classify deceleration request signals V1, V2, V3, and V4 according to their hazard level GS, which have different hazard potential values ​​GP.

[0028] Figure 2In a linearized form, example curves illustrating the variation of torque M with time t are simplified based on two different torque gradients G1 and G2. The torque M shown can be generated as either a positive or negative torque at the wheel 30 of the axle 31 of the vehicle 10, where, for simplicity... Figure 2 Only the positive torque curve is shown. The torque M1 is reached at time t1 using the first torque gradient G1, which is less than the torque M2 reached at the same time t1 using the second torque gradient G2. The slope of the second torque gradient G2 is steeper than that of the first torque gradient G1. Using the second torque gradient G2 allows the torque M to change at a faster rate than using the first torque gradient G1. For example, in... Figure 4 The first gradient limit value G is schematically marked in the diagram. L1 Or the second gradient limit G L2 Upper limits for the torque gradients G1 and G2 can be predetermined in the control technology to limit the rate of change of torque M with time t. For example, Figure 2 The torque gradients G1 and G2 shown can respectively form the first gradient limit G. L1 Second gradient limit G L2 This allows other torque gradients that are technically permissible in control to operate within the region formed by torque gradients G1, G2, and the t-axis. For example, the first gradient limit G... L1 The design can be used to ensure or extend the minimum service life L of the transmission components 21 of the electric drive 20 (e.g., bearings in the motor and / or transmission of the electric drive 20). For example, a second gradient limit G. L2 It can be designed to enhance the deceleration effect W on vehicle 10. Second gradient limit G L2 Therefore, for example, it can be higher than the first gradient limit G. L1 This allows or requires a higher rate of change of torque M per unit time t in control technology.

[0029] Figure 3 In a linearized form, the time t-variance of the driving parameters was simplified and plotted for two different driving scenarios. Figure 4 The exemplary accelerator pedal signal curves F1, F2 and I2 shown are for the accelerator pedal signal I2. Figure 4 The brake pedal signal curves B1 and B2 represent the brake pedal signal I1. The driving situation represented by the first accelerator pedal signal curve F1 (shown as a solid line) and the first brake pedal signal curve B1 (shown as a solid line) can correspond to, for example, an emergency braking situation. The first accelerator pedal signal curve F1 has a steep negative slope until it reaches zero at time t1. The first brake pedal signal curve B1 has a steep slope. The time interval between time points t1 and t2 corresponds to the initial switching time t_t between the accelerator pedal device that generates the accelerator pedal signal I2 when the driver is unloading and the brake pedal device that generates the brake pedal signal I1 when the driver is loading.W1 The switching time in emergency braking situations may be relatively short, therefore the initial switching time t W1 Emergency braking situations can be detected by, for example, the gradients and other characteristic features of the first accelerator pedal signal curve F1 and the first brake pedal signal curve B1. In contrast, driving situations represented by, for example, the second accelerator pedal signal curve F2 (shown as dashed lines) and the second brake pedal signal curve B2 (shown as dashed lines) can correspond to normal braking situations where emergency braking with the greatest possible deceleration effect W is not required. The negative gradient of the second accelerator pedal signal curve F2 is smaller than that of the first accelerator pedal signal curve F1 until it reaches zero at time point t3. The slope of the second brake pedal signal curve B2 is smaller than that of the first brake pedal signal curve B1. The second switching time T between time points t3 and t4... W2 Greater than the first switching time T between time points t1 and t2 W1 Therefore, the second switching time T W2 In addition, the slopes and other characteristic features, such as the second accelerator pedal signal curve F2 and the second brake pedal signal curve B2, can enable the detection of normal braking conditions relative to emergency braking conditions.

[0030] Figure 4 A control unit 60 for a vehicle 10 according to one embodiment is shown. The control unit 60 has a brake controller 40 and a drive controller 50 connected to the brake controller 40 using signal technology. The brake controller 40 is configured to control the braking function of the vehicle 10 and has a first data processing unit 41 and a first storage unit 42 connected to the first data processing unit 41. The drive controller 50 has a second data processing unit 51 and a second storage unit 52 connected to the second data processing unit 51. The drive controller 50 is configured to provide a drive control signal A to an electric actuator 20 of the vehicle 10. The electric actuator 20 is configured to generate torque M on the wheels 30, according to… Figure 4 The view shows that torque M is generated on the two wheels 30 of the axle 31 of the vehicle 10. The brake controller 40 is configured to receive deceleration request signals V1, V2, V3, and V4, evaluate them, and classify them, for example, by the first data processing unit 41 into classified deceleration request signals V. K The first data processing unit 41 can perform evaluation and classification, for example, by means of evaluation instructions and classification rules stored in the first storage unit 42. For example, classification rules for hazard levels GS with associated hazard potential values ​​(GP) can be stored in the first storage unit 42, thereby enabling the evaluation and classification of deceleration request signals (V1, V2, V3, V4) based on hazard levels (GS) with different hazard potential values ​​(GP), resulting in classified deceleration request signals (V...). KAccording to the illustrated embodiment, the brake controller 40 is configured to classify the deceleration request signal V. K The signal is transmitted to the drive controller 50.

[0031] According to the illustrated embodiment, the drive controller 50 is configured to receive a classified deceleration request signal V from the brake controller 40. K And based on the classified deceleration request signal V K Determine the gradient limits G of the torque gradients G1 and G2 of the electric drive 20. L1 G L2 For example, two different gradient limits G1 and G2 of the torque gradient of the electric drive 20 can be set. L1 G L2 The data is stored in the second storage unit 52 of the drive controller 50, and the second data processing unit 51 can be configured to process the classified deceleration request signal V. K Choose these two gradient limits G L1 G L2 One of them. Then, it can be considered that the determined gradient limit G is taken into account. L1 G L2 In this case, the electric actuator 20 is controlled by the drive control signal A so that the torque M generated on the wheel 30 does not exceed the determined gradient limit G of the torque gradients G1 and G2. L1 G L2 For example, the brake controller 40 can be configured to respond to a deceleration request signal V. K When classified as a potential emergency braking situation, a value higher than the first gradient limit G is selected. L1 Second gradient limit G L2 This is to enhance the deceleration effect W of the negative torque M provided on wheel 30. For example, brake controller 40 can be configured to respond to deceleration request signal V. K When classified as normal braking, select a value lower than the second gradient limit G. L2 First gradient limit G L1 This is to ensure or extend the minimum service life L of the transmission components 21 of the electric drive 20. For example, the brake controller 40 can be configured to respond to a deceleration request signal V. K When classified as a potential emergency braking situation, a value higher than the first gradient limit G is selected. L1 Second gradient limit G L2 This is to enhance the deceleration effect W of the negative torque M provided on wheel 30. In principle, it is also conceivable that the second data processing unit 51 of the drive controller 50 is configured to calculate another gradient limit, as the first gradient limit G. L1 Second gradient limit G L2The intermediate value between these values ​​is used to make finer adjustments and trade-offs to the component protection of the electric drive 20 in order to cope with the required deceleration effect W.

[0032] Deceleration request signals V1, V2, V3, and V4 can be generated, for example, by brake pedal device 80, accelerator pedal device 81, driver monitoring system 82, and / or vehicle monitoring system 83. Furthermore, brake pedal signal I1, accelerator pedal signal I2, driver monitoring signal I3, and / or vehicle status information I4 can also be incorporated into the evaluation and classification of deceleration request signals V1, V2, V3, and V4, for example, by supplementary inquiry or joint evaluation. Brake controller 40 can be configured to evaluate and classify deceleration request signals V1, V2, V3, and V4 into classified deceleration request signals V using signal curves B1 and B2 of brake pedal signal I1 and / or signal curves F1 and F2 of accelerator pedal signal I2. K The brake controller 40 can be configured to, replace or be added to, the friction braking device 70 of the vehicle 10 that generates a negative torque M on the wheel 30, provide a friction braking control signal 71 to achieve friction braking of the wheel 30.

[0033] Figure 5 A vehicle 10 with a control unit 60 is shown according to one embodiment. The vehicle 10 is shown, for example, as a commercial vehicle and configured as a vehicle assembly 13 with a tractor unit 11 and a trailer 12. According to the illustrated embodiment, the tractor unit 11 has two electric drives 20 configured to generate torque M at each wheel 30 of the two axles 31 of the tractor unit 11. The control unit 60 has a brake controller 40 and a drive controller 50. The drive controller 50 is configured to control the electric drives 20 via a drive control signal A. The brake controller 40 is configured to receive deceleration request signals V1, V2, V3, V4, and for this purpose may be connected, for example, using signal technology to a brake pedal device 80, an accelerator pedal device 81, a driver monitoring system 82, and / or a vehicle monitoring system 83, all of which can serve as suitable mechanisms for generating the deceleration request signals V1, V2, V3, V4. For example, the vehicle monitoring system 83 may be configured to perform environmental monitoring and collision identification on the vehicle 10 to identify potential collision objects K, for example, via optical monitoring devices. This allows, for example, the verification of deceleration request signals V1, V2 transmitted via accelerator pedal device 81 and / or brake pedal device 80, as well as deceleration request signals V1 classified as potential emergency braking situations. K Alternatively, it can be evaluated directly by combining brake pedal signal I1 and / or brake pedal signal I2, and classified into a classified deceleration request signal V. K .

[0034] Figure 6A vehicle 10 with a control unit 60 according to another embodiment is shown. The vehicle 10 is shown, for example, as a commercial vehicle and configured as a vehicle assembly 13 having a tractor 11 and a trailer 12. Figure 5 Compared to the illustrated embodiment, in this other embodiment, not only the tractor 11 but also the trailer 12 has an electric drive 20 configured to generate torque M on the wheels 32 of the driven axle 33 of the trailer 12. The trailer controller 90 of the trailer 12 is connected to the drive controller 50 of the tractor 11 via a signal line, through which a drive control signal A generated by the drive controller 50 can be transmitted to the electric drive 20 of the trailer 12. This achieves a coordinated deceleration effect between the tractor 11 and the trailer 12, for example, to prevent the trailer 12 from colliding with the tractor 11. According to an alternative embodiment, it is also conceivable in principle that only the trailer 12 has the electric drive 20, which can be controlled, for example, by the drive controller 50 and the trailer control unit 90 using drive control signals, while the tractor 11 is driven, for example, by another drive method such as combustion drive.

[0035] Figure reference numerals (part of the instruction manual): 10 vehicles 11 tractor units 12 trailers 13 vehicle combination 20 electric drives 21 Transmission Components 30 tractor wheels 31 tractor axles 32 trailer wheels 33 trailer axle 40 Brake Controller 41 First Data Processing Unit 42 First storage unit 50 drive controller 51 Second Data Processing Unit 52 Second storage unit 60 control unit 70 Friction Braking Equipment 71 Friction Braking Control Signal 80 Brake Pedal Equipment 81 Accelerator Pedal Equipment 82 Driver Monitoring System 83 Vehicle Monitoring System 90 trailer controller 100 Methods for controlling electric drives A drive control signal B1 First Brake Pedal Signal Curve B2 Second Brake Pedal Signal Curve C1 condition: "Potential emergency braking situation" Method E ends F1 First Accelerator Pedal Signal Curve F2 Second Accelerator Pedal Signal Curve G1 First Torque Gradient G2 Second Torque Gradient G L1 First gradient limit G L2 Second gradient limit GP Hazard Potential Value GS Hazard Level K potential collision object Minimum service life of L-drive components M torque I1 Brake pedal signal I2 Accelerator Pedal Signal I3 Driver Monitoring Signal I4 Vehicle Status Information S1 receives a deceleration request signal S2 evaluates and classifies deceleration request signals. S3a determines the first gradient limit. S3b determines the second gradient limit. S4a provides the first drive control signal S4b provides a second drive control signal t1 first time point t2 second time point t3 Third Time Point t4 Fourth Time Point T W1 First switching time T W2 Second switching time V1 deceleration request signal V2 deceleration request signal V3 deceleration request signal V4 deceleration request signal V K Classified deceleration request signal W slows down the vehicle.

Claims

1. A method (100) for controlling an electric drive (20), the electric drive being configured to generate torque (M) on a wheel (30) of an axle (31) of a vehicle (10), the method comprising the steps of: - Receive deceleration request signals (V1, V2, V3, V4) (S1); - Evaluate the deceleration request signals (V1, V2, V3, V4) and classify them into classified deceleration request signals (V K (S2); - Based on the classified deceleration request signal (V) K ), determine the gradient limit (G1, G2) of the torque gradient of the electric actuator (10). L1 G L2 (S3a, S3b); and - The electric actuator (20) is operated by a drive control signal (A) to determine the gradient limit (G). L1 G L2 The negative torque (M) (S4a, S4b) is generated on the wheel (30) of the axle (31).

2. The method (100) according to claim 1, characterized in that, The vehicle (10) has a brake controller (40) for controlling the braking function of the vehicle (10), and receives, evaluates, and classifies the deceleration request signals (V1, V2, V3, V4) into classified deceleration request signals (V K (S1, S2).

3. The method (100) according to claim 2, characterized in that, The vehicle (10) also has a drive controller (50) for controlling the electric drive (20), and, - According to the classified deceleration request signal (V) via the brake controller (40) and / or via the drive controller (50). K Determine the gradient limit (G1, G2) of the torque gradient of the electric actuator (20). L1 G L2 (S3a, S3b); and - The drive controller (50) manipulates the electric drive (20) using the drive control signal (50) to determine the gradient limit (G) according to the determined gradient limit (G). L1 G L2 This generates negative torque (M) (S4a, S4b).

4. The method (100) according to any one of the preceding claims, characterized in that, The deceleration request signals (V1, V2, V3, V4) are evaluated and classified into classified deceleration request signals (V K (S2) determines whether there is a potential emergency braking situation (C1).

5. The method (100) according to any one of the preceding claims, characterized in that, Based on their different potential hazard values ​​(GP) and hazard levels (GS), the deceleration request signals (V1, V2, V3, V4) are evaluated and classified into classified deceleration request signals (V K (S2).

6. The method (100) according to any one of the preceding claims, characterized in that, Based on the classified deceleration request signal (V) K ), determine the gradient limit (G) L1 G L2 ), such that the gradient limit (G) L1 The components (21) of the electric drive (20) are designed to ensure or extend the minimum service life (L) of the transmission components (21) of the electric drive (20).

7. The method (100) according to any one of the preceding claims, characterized in that, Based on the classified deceleration request signal (V) K ), determine the gradient limit (G) L1 G L2 ), such that the gradient limit (G) L2 It is designed to improve the deceleration effect (W).

8. The method (100) according to any one of the preceding claims, characterized in that, Based on the classified deceleration request signal (V) K ), determine the gradient limit (G) L1 G L2 ), such that the gradient limit (G) L1 G L2 The gradient limit (G) is located at the minimum service life (L) of the transmission component (21) of the electric drive (20) for ensuring or extending the service life of the electric drive (20). L1 ) and gradient limit (G) for improving the deceleration effect (W). L2 )between.

9. The method (100) according to any one of the preceding claims, characterized in that, The brake pedal signal (I1), accelerator pedal signal (I2), driver monitoring signal (I3), and / or vehicle status information (I4) are incorporated into the evaluation of the deceleration request signals (V1, V2, V3, V4) and classified into categorized deceleration request signals (V K (S2) 10. The method (100) according to claim 9, characterized in that, The deceleration request signals (V1, V2, V3, V4) are evaluated and classified into classified deceleration request signals (V) using the signal curves (B1, B2) of the brake pedal signal (I1) and / or the signal curves (F1, F2) of the accelerator pedal signal (I2). K (S2).

11. The method (100) according to any one of the preceding claims, characterized in that, Based on the classified deceleration request signal (V) K In addition to controlling the electric drive (20) (S4a, S4b) of the wheel (30) of the axle (31) via the drive control signal (A), it also controls the friction braking device (70) of the vehicle (10).

12. A control unit (60) for a vehicle (10), the control unit being configured to implement the method (100) according to any one of claims 1 to 11, wherein, The control unit (60) is configured to: receive, evaluate, and classify deceleration request signals (V1, V2, V3, V4) into classified deceleration request signals (V K According to the classified deceleration request signal (V) K Determine the gradient limits (G1, G2) of the torque gradient of the electric actuator (20). L1 G L2 ); and provide a drive control signal (A) for the electric drive (20) to determine the gradient limit (G) according to the determined gradient limit (G). L1 G L2 A negative torque (M) is generated on the wheel (30) of the axle (31).

13. A vehicle (10), particularly a commercial vehicle, for carrying out the method (100) according to any one of claims 1 to 11, wherein, The vehicle (10) includes: an electric drive (20) for generating torque (M) on the wheels (30) of the axle (31) of the vehicle (10); a mechanism for generating deceleration request signals (V1, V2, V3, V4); and a control unit (60) according to claim 12.

14. The vehicle (10) according to claim 13, wherein, The vehicle (10) has a plurality of axles (31) with wheels (30) that can be driven by the electric drive (20).

15. The vehicle (10) according to claim 13 or 14, wherein, The vehicle (10) is a tractor (11), a trailer (12), or a combination of vehicles (13) with a tractor (11) and a trailer (12).

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