DE102024000603A1 - Method for determining an optimal route for an electrically powered vehicle depending on the electrical energy available to the vehicle - Google Patents

Abstract

The invention relates to a method for determining an optimal route for an electrically powered vehicle depending on the electrical energy available to the vehicle, in which an energy functional is determined in advance along a potential mapped path and the optimal route is determined from this. In a method with which the accuracy of known solutions is improved, positive energy contributions obtained from braking recuperation of the electrically powered vehicle and braking-relevant obstacles on the potential path are taken into account when determining the energy functional, the braking-relevant obstacles being determined by means of a wireless traffic communication network via which the electrically powered vehicle communicates with other vehicles located in its vicinity and/or a traffic infrastructure extending along the potential path in order to receive real-time information.

Description

The invention relates to a method for determining an optimal route of an electrically driven vehicle depending on the electrical energy available to the vehicle, in which an energy functional is determined in advance along a potential mapped path and the optimal route is determined therefrom.

The WO 2011/066468 A1 reveals a vehicle management system for a vehicle fleet depending on energy consumption. When calculating energy consumption on selected routes, road conditions such as terrain, elevations and gradients, curves, as well as traffic information, speed limits and weather information occurring on the routes are taken into account. This data is taken from a map and evaluated. In addition, energy recuperation is taken into account when an energy balance of a route per meter is to be determined.

The object of the invention is to provide a method for determining an optimal travel path of an electrically powered vehicle depending on the electrical energy available to the vehicle, with which the accuracy of known solutions is improved.

The invention results from the features of the independent claims. Advantageous further developments and refinements are the subject of the dependent claims. Further features, possible applications and advantages of the invention result from the following description and the explanation of embodiments of the invention, which are shown in the figure.

The problem is solved with the subject matter of patent claim 1.

In the method explained at the beginning for determining an optimal route for an electrically powered vehicle depending on the electrical energy available to the vehicle, in which an energy functional is determined in advance along a potential mapped path and the optimal route is determined from this, positive energy contributions obtained from braking recuperation of the electrically powered vehicle and braking-relevant obstacles on the potential path are taken into account when determining the energy functional, whereby the braking-relevant obstacles are determined using a wireless traffic communication network via which the electrically powered vehicle communicates with other vehicles in its vicinity and/or a traffic infrastructure extending along the potential path in order to receive real-time information. The existing and known static information is dynamized by taking into account the current traffic situation and the traffic infrastructure, which optimizes the accuracy of the route determination. The simultaneous consideration of the positive energy contributions obtained from braking recuperation enables the range of the electrically powered vehicle to be increased. Particularly in emergency situations, for example when the vehicle battery is almost discharged, a selection of different routes can be used to select the one that offers the greatest possibility of energy recovery.

To determine the braking recuperation, data about the terrain and/or ground elevations and/or road gradients of the potential route are advantageously determined from a navigation map of the electrically powered vehicle. This makes it easier to determine routes on which energy can be recovered in the electrically powered vehicle. This energy recovery takes place through recuperation during the braking phases of the electrically powered vehicle. Furthermore, the probability of energy recovery is increased, which can increase the range of the electrically powered vehicle.

In one embodiment, a static map describing the energy balance of the electrically powered vehicle is updated with real-time information. This enables faster calculation of the energy balance and reduces the necessary computing capacity.

In one variant, the real-time information is used to continuously determine the distances of the electrically driven vehicle to the obstacles relevant to braking in order to determine their current location and to determine a regenerative braking distance of the electrically driven vehicle along the potential path. Taking the obstacles relevant to braking into account simplifies the determination of the regenerative braking distance while simultaneously evaluating the energy balance.

In one embodiment, a regenerative braking distance of the electrically driven vehicle is determined in a local environment for each of the other vehicles ahead along the optimal travel path. This allows a gradual braking process to be carried out, thereby avoiding a hard braking stop due to the driver manually braking.

It is advantageous if the energy function and/or the distances to the obstacles relevant to braking are used to determine a speed limit for the electrically powered vehicle, to which it is automatically braked in order to maintain the optimal regenerative braking distance. Adhering to the speed limit allows as much energy as possible to be saved in order to ensure a journey to the next charging station in situations where the vehicle's energy balance is low. In addition, the speed limit and recuperation in the braking phase enable power reserves and potential energy recovery and stop the consumption of large amounts of energy. In such an emergency, the energy consumption of comfort functions of the electrically powered vehicle can also be reduced, for example by restricting the air conditioning, lighting, displays and/or multimedia functions or adjusting them to minimum energy thresholds.

In a further embodiment, a triangulation method is used to determine the location of the braking-relevant obstacles. A data component of the vehicles, such as a SIM card or a GPS signal, can be used as a triangulation data point. Knowledge of the real-time position of the other braking-relevant vehicles on the road can be used to determine its effects on the regenerative braking distance of the electrically powered vehicle over a larger coverage area.

In an alternative, a swarm method is used within a vehicle fleet to compare vehicle data from other vehicles in the vehicle fleet and to determine their locations. This swarm method is used to compare vehicle sensor data, such as radar, infrared, lidar, from different vehicles. Compared to the triangulation method, the vehicle sensor data recorded in this way leads to greater accuracy in determining the regenerative braking distance.

Further advantages, features and details emerge from the following description, in which at least one embodiment is described in detail. Described features can form the subject matter of the invention on their own or in any meaningful combination, possibly also independently of the claims, and can in particular also be the subject of one or more separate applications.

• 1: Leistungskurve eines elektrisch angetriebenen Fahrzeuges.

It shows:

• 1 : Performance curve of an electrically powered vehicle.

In an electrically powered vehicle, a unit for energy recovery is designed in a control unit, by means of which the braking distances are optimized on the basis of V2X communication if a regenerative braking system is present. The electrically powered vehicle communicates wirelessly with other vehicles and units of the traffic infrastructure that are on its route.

When the energy recovery unit is activated, energy consumption is reduced to maintain comfort functions in the vehicle and on-board sensors. The route of the electrically powered vehicle, determined by a navigation system, is mapped to record road conditions and elevations or gradients and other topographical features of the route to be traveled.

In order to determine the route for the electrically powered vehicle that uses the least energy, an energy efficiency is continuously determined from a quotient of the distance to be covered and the energy consumption. Initially, the amount of energy that the electrically powered vehicle needs to cover the distance resulting from the route determined by the navigation system is taken into account. This energy efficiency value is compared with the mapped topographical data, e.g. differences in altitude and gradients to be overcome. This results in: $$\begin{array}{c}\text{power consumption}=\left(\text{Distance of the route}+\text{H}\ddot{\text{O}}\text{hen profit or}.\text{H}\ddot{\text{O}}\text{hen loss}\right)*\\ \text{Energy costs per meter}\end{array}$$

The energy costs per meter represent the average energy costs of the last 100 kilometers driven by the vehicle. The navigation system can also show the driver two or more routes. In this case, the above considerations are carried out for each suggested route.

Based on these calculations, a performance curve ( 1 ) which shows a route performance over the distance to be travelled. When selecting, the route with the highest output power and the greatest possible distance to be covered would be given the highest priority. In this case, in the event of a low battery, the driver would be suggested to use route 1.

There are other factors that are used to determine the route. The static map that describes the energy balance of the electrically driven vehicle is adapted depending on real-time traffic. Using the components of the electrically driven vehicle intended for V2X communication, distance measurements are continuously carried out to other road users moving along the route of the electrically driven vehicle or to stationary objects of the traffic infrastructure on the side of the road. The current locations of these objects are determined using a triangulation method that takes into account at least three objects to be considered. A SIM card or a GPS signal is typically used as a triangulation data point.

Knowledge of the respective real-time position of objects such as traffic lights, telephone poles, traffic signs and the like, and road users on the road is used to determine how this affects the predetermined route of the electrically powered vehicle over a larger coverage area. This makes it possible to determine an optimal regenerative braking distance between the electrically powered vehicle and not only the other vehicle immediately ahead, but also other road users, preferably vehicles, moving along the selected route 1. This results in predictive regenerative braking of the electrically powered vehicle with respect to each of these other road users by adjusting the braking components over a predetermined distance.

QUOTES INCLUDED IN THE DESCRIPTION

This list of documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions.

Cited patent literature

• WO 2011066468 A1 [0002]

Claims (8)

Method for determining an optimal route for an electrically powered vehicle as a function of the electrical energy available to the vehicle, in which an energy functional is determined in advance along a potential mapped path and the optimal route is determined from this, characterized in that when determining the energy functional, positive energy contributions obtained from braking recuperation of the electrically powered vehicle and braking-relevant obstacles on the potential path are taken into account, the braking-relevant obstacles being determined by means of a wireless traffic communication network via which the electrically powered vehicle communicates with other vehicles located in its vicinity and/or a traffic infrastructure extending along the potential path in order to receive real-time information. Procedure according to Claim 1 , characterized in that, in order to determine the brake recuperation, data on a terrain and/or ground elevations and/or road gradients of the potential route are determined from a navigation map of the electrically powered vehicle. Procedure according to Claim 1 or 2 , characterized in that a static map describing an energy balance of the electrically powered vehicle is updated with real-time information. Procedure according to Claim 1 , 2 or 3 , characterized in that the real-time information is used to continuously determine distances of the electrically driven vehicle to the braking-relevant obstacles in order to determine their current location and to determine a regenerative braking distance of the electrically driven vehicle along the potential path. Procedure according to Claim 4 , characterized in that a regenerative braking distance of the electrically driven vehicle is determined in a local environment for each other vehicle driving ahead along the optimal travel path. Procedure according to Claim 5 , characterized in that by means of the energy functional and/or the distances to the braking-relevant obstacles, a speed limit is determined for the electrically driven vehicle, to which it is automatically braked in order to maintain the optimal regenerative braking distance. Procedure according to Claim 4 , 5 or 6 , characterized in that a triangulation method is used to determine the location of the braking-relevant obstacles. Procedure according to Claim 4 , 5 or 6 , characterized in that within a vehicle fleet a swarm method is used to compare vehicle data of other vehicles in the vehicle fleet and to determine their locations.

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