Methods for improving energy recuperation in an electric vehicle

Abstract

Method for improving recuperation in an electric vehicle with at least two electrically driven axles, comprising the following steps: Departure detection by analyzing a vehicle tilt angle and / or navigation data using an analysis unit, Control of a motor control unit for coupling a secondary axle that was previously disconnected, Use of both electric axles, namely the secondary axle and a primary axle, for recuperation of braking energy of the vehicle during descent.

Description

[0001] The technical field is methods for improving energy recuperation in an electric vehicle.

[0002] The state of the art includes several approaches to optimizing the recuperation and use of electric drives in vehicles.

[0003] EP 3 634 825 B1 discloses a method for controlling a differential braking system of a vehicle, wherein the vehicle has at least one auxiliary braking system.

[0004] US 2020 / 0 171 956 A1 discloses a vehicle and a hill descent control procedure provided for it to enable stable driving on a downhill road.

[0005] DE 10 2016 116 538 A1 discloses a drive train for a motor vehicle, in particular for an electric vehicle, with two driven axles.

[0006] DE 10 2017 213 199 A1 discloses an electrically powered vehicle with multiple rear axles in which the level and axle load distribution are changed via an adjustment device during recuperation operation. This is intended to improve energy recovery. The axle load is pneumatically controlled to achieve an even load distribution across the axles.

[0007] DE 10 2018 214 246 A1 relates to a method for controlling the operation of an electrically powered vehicle using predicted driving data. Navigation data, traffic information, and weather data are taken into account to proactively adjust the energy distribution in the vehicle.

[0008] DE 10 2016 116 538 A1 describes an electric drive system with a transmission gearbox that includes several switching stages.

[0009] DE 10 2023 003 283 A1 discloses a control system for electric vehicles in which artificial intelligence (AI) is used to optimize energy consumption and to adapt the driving strategy.

[0010] DE 10 2019 124 649 A1 concerns a vehicle with a lift axle, the raising or lowering of which is dependent on slippage or axle load.

[0011] The object of the invention is to provide an improved method for improving recuperation, which ensures reliable vehicle control on routes with a gradient.

[0012] The invention relates to a method for improving recuperation in an electric vehicle with at least two electrically driven axles. The method comprises the following steps: detection of a descent by means of an analysis of a vehicle tilt angle and / or navigation data by an analysis unit, control of a motor control unit to couple a previously disconnected secondary axle, and use of both electric axles, namely the secondary axle and a primary axle, to recuperate braking energy from the vehicle during the descent.

[0013] An electric vehicle is a vehicle with at least two electrically driven axles that can be used independently or together for energy generation and braking. The primary axle is the vehicle's main drive axle, while the secondary axle is an additional axle that can be decoupled in certain driving situations. A descent refers to a topographical road feature with a gradient that necessitates a specific adjustment of the braking process through the use of recuperation. The analysis unit is an electronic unit that processes gradient angle and navigation data to detect descents. The motor control unit is a device for controlling the electric drives and implementing the coupling of the secondary axle.

[0014] One advantage of the method lies in maximizing recuperation power through the use of the secondary axis.

[0015] Another advantage is the reduction of wear on the mechanical brakes through optimized use of the recuperation of the electric drives during the braking process.

[0016] Advantageously, the vehicle's tilt angle can be detected using an integrated tilt sensor and / or an accelerometer. A tilt sensor is a device that measures the vehicle's angle of inclination relative to the horizontal, while an accelerometer detects changes in vehicle speed and direction. This enables precise detection of descents, even under complex road conditions.

[0017] Advantageously, navigation data can be acquired using a GPS sensor connected to the vehicle, which, taking map data into account, allows the system to detect upcoming exits on the vehicle's lane. The GPS (Global Positioning System) sensor is used for position determination and navigation. This enables the vehicle to react to exits early and activate regenerative braking in a timely manner.

[0018] Advantageously, the analysis unit can use a prediction function to determine departures within a defined route segment. The prediction function is an algorithm that forecasts future departures based on navigation data and topographic information.

[0019] Advantageously, the coupling of the secondary axle can be achieved via an electronic transmission, which is controlled by the engine control unit. The electronic transmission is a mechanism that can efficiently couple or decouple the drivetrain of the secondary axle. This enables precise and reliable control of the axles.

[0020] Advantageously, the secondary axle is only engaged when the remaining battery capacity of the electric vehicle falls below a predefined threshold. Battery capacity describes the amount of energy remaining in the vehicle's battery. This further improves the vehicle's energy efficiency.

[0021] Advantageously, the analysis unit can classify the degree of descent, whereby the coupling of the secondary axle only occurs at a predefined minimum vehicle tilt angle of at least 10° and / or a total descent length of at least 50 m. This ensures that the coupling of the secondary axle only occurs in relevant driving situations with a sufficient vehicle tilt angle and / or a sufficient overall length.

[0022] Advantageously, the analysis unit can use a machine learning AI model to optimize the efficiency of regenerative braking via the secondary axle based on previous journeys. A machine learning model is an algorithm that learns from historical data and improves future decisions. This continuously optimizes regenerative braking, increasing the vehicle's range and lifespan.

[0023] Advantageously, the secondary axle coupling can be automatically deactivated when the vehicle leaves a section of the descent and / or increased slip is detected on the secondary axle. Increased slip describes a situation in which the secondary axle wheels spin or lose traction. This ensures the vehicle's safety and stability.

[0024] A further aspect of the invention is a vehicle for carrying out the method described above. The vehicle comprises the analysis unit for detecting the descent by analyzing the vehicle's tilt angle and / or navigation data, the motor control unit for controlling the coupling of the previously disconnected secondary axle, and at least two electrically driven axles, namely the secondary axle and a primary axle, which are designed such that both electric axles are used for recuperating braking energy during a descent. Furthermore, the vehicle has an electronic transmission for coupling and / or disconnecting the secondary axle.

[0025] One advantage of the vehicle is the precise detection of descents using the analysis unit, which analyzes the vehicle's tilt angle and / or navigation data. This enables early and reliable preparation for recuperation processes.

[0026] Another advantage lies in the motor control unit, which ensures the targeted engagement of the previously disengaged secondary axle. This allows for the efficient use of both electrically driven axles—the secondary and primary axles—for recuperating braking energy during descents. Additionally, the electronic transmission enables smooth and reliable engagement of the secondary axle, thereby improving the vehicle's flexibility and performance in varying driving situations.

Claims

[1] Method for improving recuperation in an electric vehicle with at least two electrically driven axles, a primary axle and a secondary axle, comprising the following steps: Departure detection by analyzing a vehicle tilt angle and / or navigation data using an analysis unit, Control of a motor control unit for coupling the secondary axle, which was previously disconnected, Use of both electric axles, namely the secondary axle and the primary axle, for recuperation of braking energy from the vehicle during descent, characterized by , that the coupling of the secondary axle is achieved by an electronic transmission, which is controlled by the engine control unit, wherein the electronic transmission is a mechanism that couples or decouples a drive train of the secondary axle, wherein the navigation data is acquired by means of a GPS sensor connected to the vehicle and, taking into account map data, an upcoming exit on a lane of the vehicle is detected, wherein the analysis unit uses a prediction function to determine exits within a defined section of the route. [2] Method according to claim 1, wherein the detection of the vehicle tilt angle is carried out by means of a tilt sensor and / or an acceleration sensor integrated in the vehicle. [3] Method according to one of the preceding claims, wherein the secondary axle is coupled only if the remaining battery capacity of the electric vehicle falls below at least a predetermined threshold. [4] Method according to one of the preceding claims, wherein the analysis unit is suitable for classifying a degree of descent, and the coupling of the secondary axle only takes place at a predetermined minimum value of the vehicle inclination angle of at least 10° and / or at a total length of the descent of at least 50 m. [5] Method according to any of the preceding claims, wherein the analysis unit uses a machine learning AI (artificial intelligence) model to optimize the efficiency of the recuperation by the secondary axle based on previous journeys. [6] Method according to any of the preceding claims, wherein the coupling of the secondary axle is automatically deactivated when the vehicle leaves a section of the descent and / or increased slip is detected on the secondary axle. [7] Vehicle for carrying out a method according to any one of claims 1 to 6, comprising: the analysis unit for detecting departure by analyzing the vehicle's tilt angle and / or navigation data, the motor control unit for controlling the coupling of the previously decoupled secondary axle, at least two electrically driven axles, namely the secondary axle and a primary axle, designed so that both electric axles are used to recuperate braking energy during a descent, the vehicle also has an electronic transmission for coupling the secondary axle.