Determining vehicle energy requirement

Abstract

Estimating energy requirement 116 for a vehicle traversing a route, based on vehicle energy information 112 (e.g. energy consumption at various speed), and route data 114 including predicted average s

Description

10 03 25 TECHNICAL FIELD The present disclosure relates to determining vehicle energy requirement. Aspects of the 5 invention relate to a control system for a vehicle, to a method for a vehicle, to a vehicle, and to a non-transitory, computer-readable storage medium. BACKGROUND It is known to provide an estimate of a vehicle’s range based on current fuel or energy 10 reserves. This range estimate may be based on a planned route to a specific destination. However, the accuracy of these estimates can vary greatly. The range estimate is reliably accurate in less than 50% of cases. This can be potentially problematic, as the range estimate may indicate that the vehicle has sufficient fuel or energy to reach its planned destination, whereas, the vehicle may in fact need to refuel or recharge before reaching the destination. 15 This may be a greater problem for electric vehicles, as recharging en route is not as convenient as refuelling. It is an aim of the present invention to address one or more of the disadvantages associated with the prior art. 20 SUMMARY OF THE INVENTION Aspects and embodiments of the invention provide a control system for a vehicle, a method for a vehicle, a vehicle, and a non-transitory, computer-readable storage medium as claimed in the appended claims. 25 According to an aspect of the invention there is provided control system for a vehicle, the control system comprising: an input to receive energy information for the vehicle, and data indicative of a route between a first location and a second location, including a plurality of route segments wherein each route segment corresponds to a portion of the route; an output to 30 output the vehicle energy requirement for the plurality of route segments; and a processor to obtain, from the route data signal, for each route segment of the plurality of route segments, a projected average speed and a projected deviation from the projected average speed, and determine an energy requirement for each route segment in dependence on the energy information and the projected deviation for that segment. 35 10 03 25 In this way, the invention provides an improvement in the accuracy of range prediction for vehicles, by considering both the predicted average speed for a journey segment, and the predicted deviation from the predicted average speed. 5 According to a further aspect of the invention there is provided a control system for a vehicle, the control system comprising one or more controllers, the control system comprising: an input to receive an energy information signal comprising energy information for the vehicle, and to receive a route data signal indicative of a route between a first location and a second location, including a plurality of route segments wherein each route segment corresponds to a portion 10 of the route; an output to output an energy requirement signal indicative of the vehicle energy requirement for the plurality of route segments; and a processor to obtain, from the route data signal, for each route segment of the plurality of route segments, a projected average speed and a projected deviation from the projected average speed, determine an energy requirement for each route segment in dependence on the energy information, the projected average 15 speed and the projected deviation for that segment. In this way, the control system of the invention is adapted to consider the potential variations in vehicle speed in a route segment, where such variations in speed can result in variations in the energy consumed, and so provide a more accurate estimate of the energy required. 20 The route data signal comprises data on interruptions in the route, wherein an interruption corresponds to a location where the vehicle may be required to stop or decelerate, and wherein the projected deviation is based on the number of interruptions. Interruptions may be understood to comprise traffic lights, traffic islands, roundabouts, “stop” junctions, “give way” 25 junctions, and the like. Considering interruptions in this way is an efficient and convenient manner of providing a projected deviation from an average projected average speed. The route data signal may be received from a navigation module, which may be internal or external the vehicle. 30 Optionally, the energy information signal comprises information relating to the vehicle’s energy consumption at differing vehicle speeds. The energy information signal may be received from a power train control module of the vehicle. 35 In an embodiment, the route data signal comprises the projected average speed for each route segment. 10 03 25 Optionally, the energy information signal may comprise an energy status of the vehicle, and 5 the processor is to calculate, dependent on the energy requirement for each route segment and the energy status, a future energy status of the vehicle at the end of the route; and output is to output a future energy signal indicative of the future energy status. The energy status may comprise data indicative of the current energy reserves of the vehicle, for example a current state of charge for an electric vehicle, or a fuel level for a combustion-driven vehicle. 10 Optionally, the route segments of the route are substantially contiguous, and correspond to substantially the complete route between the first location and the second location. In this way, the combination of all route segments is representative of the complete route. 15 In an embodiment, the input is to receive a driver style signal indicative of a driving style associated with the present driver of the vehicle, and the energy requirement for each route segment is determined in dependence on driving style, the energy information and the projected representative speed for that segment. The driver style signal may comprise a driver style value. The level of aggressiveness in acceleration can alter the energy consumed while 20 accelerating, therefore a driver who accelerates quickly to a target speed will use more energy than a driver who accelerates more gradually to that speed. According to another aspect of the invention there is provided a vehicle comprising a control system as discussed above. Such a vehicle can provide a more accurate range estimate for 25 a given route. According to a still further aspect of the invention there is provided a method for a vehicle, comprising: receiving an energy information signal comprising energy information for the vehicle; receiving a route data signal indicative of a route between a first location and a second 30 location, including a plurality of route segments wherein each route segment corresponds to a portion of the route; obtaining, from the route data signal, for each route segment of the plurality of route segments, a projected average speed and a projected deviation from the projected average speed; determining an energy requirement for each route segment in dependence on the energy information, the projected average speed, and the projected 35 deviation for that segment; outputting an energy requirement signal indicative of the energy requirement for the plurality of route segments. 10 03 25 Optionally, the route data signal comprises data on interruptions in the route, wherein an interruption corresponds to a location when the vehicle may be required to stop, and wherein the projected deviation is based on the number of interruptions. 5 In an embodiment, the energy information signal comprises information relating to the vehicle’s energy consumption at differing vehicle speeds. Optionally, the route data signal is indicative of the projected average speed for each route segment. 10 In an embodiment, the route segments of the route are substantially contiguous, and correspond to substantially the complete route between first location and the second location. Optionally, the method comprises receiving a driver style signal indicative of a driving style 15 associated with the present driver of the vehicle, and determining the energy requirement for each route segment in dependence on driving style, the energy information and the projected representative speed for that segment According to yet further aspect of the present invention there is provided a non-transitory, 20 computer-readable storage medium storing instructions thereon that, when executed by one or more electronic processors, causes the one or more electronic processors to carry out the method discussed above. Within the scope of this application it is expressly intended that the various aspects, 25 embodiments, examples and alternatives set out in the preceding paragraphs, in the claims and / or in the following description and drawings, and in particular the individual features thereof, may be taken independently or in any combination. That is, all embodiments and / or features of any embodiment can be combined in any way and / or combination, unless such features are incompatible. The applicant reserves the right to change any originally filed claim 30 or file any new claim accordingly, including the right to amend any originally filed claim to depend from and / or incorporate any feature of any other claim although not originally claimed in that manner. 35 BRIEF DESCRIPTION OF THE DRAWINGS 10 03 25 One or more embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 shows a block diagram of a control system according to an embodiment of the 5 invention; Figure 2 shows a block diagram of a system comprising the control system of Figure 1; Figure 3 shows a flow chart showing a method according to an embodiment of the invention; 10 Figure 4 shows a vehicle in accordance with an embodiment of the invention. DETAILED DESCRIPTION 15 A control system for a vehicle in accordance with an embodiment of the present invention is described herein with reference to the accompanying Figure 1. The control system 100 comprises a processor 102, and input 104 and an output 106. The input 104 is suitable for receiving an energy information signal 112 and a route data signal 114. The route data signal 20 114 is indicative of a route between a first location and a second location, including a plurality of route segments wherein each route segment corresponds to a portion of the route. The processor 102 is suitable to obtain, for each route segment of the plurality of route segments, a projected average speed and a projected deviation from the projected average speed. The processor 102 is further suitable to determine an energy requirement for each route segment 25 of the plurality of route segments in dependence on the energy information, the projected average speed and the projected deviation for that segment. The output 106 is suitable for outputting an energy requirement signal 116 indicative of the vehicle energy requirement for the plurality of route segments. 30 The projected deviation may be derived from information indicating locations on the route where the vehicle speed potentially departs from the projected average speed for the route segment in question. In particular, locations where the vehicle speed potentially drops below the projected average speed provide useful deviation information for use in determining energy requirements of the vehicle. The projected deviation may be calculated in a variety of 35 ways including statistical methods for calculating variance, standard deviation or the like, but is not limited to statistical definitions and may also be calculated in other manners. 10 03 25 The energy information signal 112 may comprise information relating to the vehicle’s energy consumption at differing vehicle speeds. The route data signal 114 may comprise the projected average speed for each route segment. 5 The route data signal 114 may comprise data on interruptions in the route, wherein an interruption may for example correspond to a location when the vehicle may be required to stop. Interruptions may further comprise locations where the vehicle maybe required to decelerate. The projected deviation for a segment may be a function of the total number of 10 interruptions. Interruptions may be understood to comprise traffic lights, traffic islands, roundabouts, “stop” junctions, “give way” junctions, and the like. Each interruption indicates a potential deviation of the vehicle speed from the average speed for that route segment. The control module 100 combines segment projected average speed and segment average speed deviation. In this way, the control system 100 allows for how much acceleration and 15 deceleration are expected within each segment. The number of interruptions may be considered to be analogous to the effect of deviations on the energy consumption of the vehicle, and provides a useful approximation of the speed deviation from the predicted average. Using the number of interruptions is also relatively straight-forward and easy to implement. 20 A vehicle’s energy consumption varies non-linearly with vehicle speed. For example, it may require less energy to travel a distance of 1km at 20 kph than to travel the same distance at 50 km / h. In addition, for any given average speed maintaining a constant speed requires less energy than a combination of decelerating and accelerating, for example to reacquire a target 25 speed following an interruption. Consider an example of a route segment that is 10km long and the projected average speed is 50 kph. This average speed could apply to a vehicle travelling at a constant 50 kph and could also apply to a vehicle that is repeatedly accelerating from 0 kph to 100 kph and then decelerating back to 0 kph, repeated for 10 km. These two examples would have significantly different energy usages. As such, taking account of 30 potential variations in vehicle speed will make route energy usage prediction more accurate. The route data signal 114 may comprise general information on the route which the control system 100 may analyse to extract the interruptions. Additionally or alternatively, the data identifying the interruptions may be have already been extracted and the number of 35 interruptions is comprised within the route data signal 114 such that less analysis is required by the control system 114. The route data signal 114 may comprise details of the type of interruptions. Further, the route data signal 114 may comprise an approximation of the route 10 03 25 data, to reduce the data transmission and processing loads. An example route data signal 114 comprises the number of segments, the length of each segment, the projected average speed for each segment and the number of interruptions for each segment. 5 The deviation may be calculated in a number of ways, as will be apparent to the person skilled in the art. For example, statistical sample standard deviation may be used. In a further example, the deviation is calculated according to the formula: Original energy requirement New energy requirement = —---------------------------- (factor A number of interruptions) 10 where the factor is calibratable, but will likely be slightly less than 1, for example 0.98). In this way, as the number of interruptions increases, the more the energy required to complete the segment will be increased. 15 The original energy requirement may be calculated based on the segment length, the segment average speed and the average energy consumption at that speed. In an example where the segment length is 10km, the segment average speed is 30kph, and the average energy consumption at 30kph is 200 Wh / km, the original energy requirement to complete the segment 20 may be calculated as 10 x 200 = 2000Wh. The inventors have discovered that the use of a factor in the range 0.80 to 0.99, typically in the range 0.95 to 0.98, provides improved results for estimating a vehicle’s energy requirement for a route between a first location and a second location. The factor may be configurable, for 25 example, based on use data from vehicles. This formula provides useful results when considering a vehicle’s energy consumption based on a projected deviation from a projected average speed, however, it will be understood that other manners of determination may be used. For example, using data collected from one or 30 more vehicles, it would be possible to compare an RMS speed trace for a route segment with the average speed prediction and integrate the area under the curve. In another example, a projected representative speed is derived from the projected average speed for the route segment and the projected deviation from the projected average speed. 35 The projected representative speed may then be used in determining the energy requirement for the segment, in combination with data from the energy information signal. 10 03 25 Adding together the energy used for each segment allows the total energy for the journey to be estimated. The use of a plurality of route segments allows for different speeds across the route to be taken into account. However, assuming a constant speed within the segments 5 limits the accuracy of that estimation. Embodiments of the present invention consider the potential interruptions in a journey such as features including traffic, traffic lights, sharp bends, etc on the route for each segment. Each of these interruptions may cause the vehicle to have to decelerate and / or stop and then accelerate again, which will adversely affect the energy consumption of the vehicle. By considering these interruptions, it is possible to estimate how 10 much the vehicle speed might deviate from the segment average. This deviation is proportional to the amount of acceleration / deceleration during the segment. Acceleration / deceleration is directly proportional to energy usage. Knowing energy usage more accurately will allow the accuracy of the total journey energy prediction to be improved. 15 The input may be suitable to receive a driver style signal (not shown). The driver style signal is indicative of a driving style associated with the present driver of the vehicle. When a driver style signal has been received, the energy requirement for each route segment may be determined in dependence on driving style in combination with the energy information and the projected representative speed for that segment. The driver style signal may be received from 20 another controller within the vehicle, such as a vehicle supervisory controller. The driver style signal may comprise a driver style value representing a driver’s aggressiveness while driving. The driver style value may be derived from how aggressively a driver attempts to acquire a speed target. For example, where a speed limit step changes from 30 kph to 50 kph, whether the driver gently accelerates or rapidly accelerates to acquire 50 kph. 25 The energy information signal 112 may comprise an energy status of the vehicle. The processor 102 is suitable to calculate, dependent on the energy requirement for each route segment and the energy status, a future energy status of the vehicle at the end of the route. The output 106 of the control system 100 may be suitable to output a future energy signal 30 indicative of the future energy status. In some examples the future energy signal may be output to a third entity such as a cloud server or other remote server. In some examples, outputting the future energy signal may comprise providing the future energy signal to an output device, such as to a display screen 35 e.g. a dashboard display of the vehicle or a display of a portable device in communication with the control system 100, such as a driver's mobile device. 10 03 25 The control system 100 may be arranged to receive data indicating one or more charge points or fuel points with respect to the route (e.g. from a further control system). The one or more charge points may each indicate a location at which the vehicle can recharge a battery, and the fuel points may each indicate at location at which the vehicle can obtain fuel. The data 5 indicating one or more charge points and / or fuel points with respect to the route may be determined in dependence on the future energy status of the vehicle and map data. The control system 100 may be arranged to then provide, to a vehicle output apparatus (e.g. a driver display or a speaker), an indication of the one or more charge point locations or fuel point locations with respect to the route. 10 The control system 100 may be arranged to receive data on current conditions on a road segment, which may be used in calculating the deviation for that segment. For example, the input may receive traffic data, as part of the route data signal. The control system 100 may be adjust the deviation in light of the traffic data. In an example, traffic volumes may limit the 15 projected average vehicle speed for the segment, or significant traffic volumes may result in multiple stop-start operations. Referring now to Figure 2, there is shown a block diagram of a system, indicated generally by the reference numeral 200, comprising the control system 100, a powertrain control module 20 118 and a navigation module 122. The energy information signal 112 may be received from the powertrain control module 118 of the vehicle. The powertrain control module 118 may be considered to handle vehicle-related data and may manage vehicle data for a current state of a vehicle. The powertrain control module 118 stores and / or manages data such as fuel and / or battery information, vehicle data, consumption behaviour, motor losses, and non-25 tractive loading data. The navigation module 122 may be considered to handle navigation-related data. The route data signal 114 may be received from the navigation module 122. The navigation module 122 may store and / or manage data such as map data, route data, and charging point location data. The navigation module 122 may be integral to the vehicle, for example an on-board navigation system; peripheral to the vehicle, for example an electronic 30 device such as a mobile phone that is dockable with the vehicle; or remote from the vehicle, for example on a cloud server with which the vehicle may communicate. It will be understood the system 200 may comprise further control modules of the vehicle as appropriate. For example, the system may further comprise a display module (not shown) suitable for displaying to a driver of the vehicle an indicator based on the energy requirement signal 120, 35 or may comprise a control module (not shown) suitable for further processing the energy requirement signal. 10 03 25 Referring now to Figure 3, there is shown a method indicated generally by the reference numeral 300, according to an embodiment of the invention. The method 300 may be implemented by the control system 100 described in relation to Figure 1. At block 302, the 5 method comprises receiving an energy information signal comprising energy information for the vehicle. At block 304, the method 300 comprises receiving a route data signal. The route data signal is indicative of a route between a first location and a second location. The route comprises a plurality of route segments wherein each route segment corresponds to a portion of the route. The route segments may be substantially contiguous, and correspond to 10 substantially the complete route between the first location and the second location. The route data signal comprises details of each route segment, and may include a projected average speed for each route segment. To put it another way, in some examples, the projected average speed may be a function of the speed limits on a given road. 15 At block 306, the method 300 comprises obtaining, from the route data signal, a projected deviation from a projected average speed for each route of the plurality of route segments. The projected deviation may be included in the route data signal, or may be derived therefrom. The projected deviation corresponds to how much the vehicle is expected to depart from a projected average speed for that route segment. The projected deviation may be based on a 20 number of interruptions in the route segment, where the vehicle may be required to reduce speed or stop before accelerating again to continue their journey. At block 308, the method 300 comprises determining an energy requirement for each route segment in dependence on the energy information, the projected average speed, and the 25 projected deviation for that segment. At block 310, the method 300 comprises outputting an energy requirement signal indicative of the energy requirement for the plurality of route segments. 30 The control system 100 and method 300 described herein are particularly suitable for use with an electrical vehicle, however they are not limited thereto and may be used with a vehicle of any powertrain type. The energy stored in a battery of an electric vehicle may be termed the 'state of charge' of the battery. It will be appreciated by a person skilled in the art that the energy stored by a given amount of charge also depends on the voltage of the battery, 35 and the voltage depends on the total amount of charge in the battery. Thus there is a non 10 03 25 linear relationship between the 'energy stored' and the 'state of charge' of the battery, since the voltage increases with the state of charge. Figure 4 illustrates a vehicle 400 according to an embodiment of the present invention. The 5 vehicle 400 comprises a control system 100 as illustrated in Figure 1. The control system 100 described herein in relation to Figures 1 and 2, comprise one processor 102, although it will be appreciated that this is merely illustrative. The processor 102 comprises processing means and memory means. The processing means may be one or 10 more electronic processing device which operably executes computer-readable instructions. The memory means may be one or more memory device. The memory means is electrically coupled to the processing means. The memory means is configured to store instructions, and the processing means is configured to access the memory means and execute the instructions stored thereon. The processor 102 comprises an input means and an output means. The 15 input means may comprise an electrical input of the processor 102. The output means may comprise an electrical output of the processor 102. The method 300 described herein in relation to Figure 3 may be implemented by a storage medium, for example a non-transitory, computer-readable storage medium, storing 20 instructions thereon that, when executed by one or more electronic processors, causes the one or more electronic processors to carry out the method 300. It will be appreciated that various changes and modifications can be made to the present invention without departing from the scope of the present application. 25

Claims

10 03 251. A control system for a vehicle, the control system comprising one or more controllers, the control system comprising:5 an inputto receive an energy information signal comprising energy information for the vehicle, andto receive a route data signal indicative of a route between a first location and a second location;10 an output to output an energy requirement signal indicative of the vehicle energyrequirement for the route; anda processor toobtain, from the route data signal a projected average speed and a projected deviation from the projected average speed, and15 determine an energy requirement for each route segment independence on the energy information, the projected average speed and the projected deviation from the projected average speed for the route, wherein the route data signal comprises data on interruptions in the route, wherein an interruption corresponds to a location where the vehicle may be required to stop or20 decelerate, and wherein the projected deviation is based on the number of interruptions.

2. A control system according to claim 1, wherein the projected deviation for a segment is a function of the total number of interruptions.25 3. A control system according to claims 1 or 2, wherein the energy requirement, NE, fora segment of the route is determined using the formula:NE = OE / (Factor * n),where:OE is the energy requirement determined for the projected average speed;30 Factor is a number close to, but less than, one; andn is the number of interruptions determined for the route.

4. A control system according to any preceding claim, wherein the route comprises a plurality of route segments, wherein each route segment corresponds to a portion of the route,35 and wherein the route data signal comprises the projected average speed for each route segment.10 03 255. A control system as claimed claim 4, wherein the route segments of the route are substantially contiguous, and correspond to substantially the complete route between the first location and the second location.5 6. A control system according to any preceding claim, wherein the energy informationsignal comprises an energy status of the vehicle, and the processor is to calculate, dependent on the energy requirement for the route and the energy status, a future energy status of the vehicle at the end of the route; and the output is to output a future energy signal indicative of the future energy status.

107. A control system as claimed in any preceding claim, wherein the input is to receive a driver style signal indicative of a driving style associated with the present driver of the vehicle, and the energy requirement for each route segment is determined in dependence on driving style, the energy information and the projected representative speed for that segment.

158. A vehicle comprising a control system according to any of claims 1 to 7.

9. A method for a vehicle, comprising:receiving an energy information signal comprising energy information for20 the vehicle;receiving a route data signal indicative of a route between a first location and a second location;obtaining, from the route data signal a projected average speed and a projected deviation from the projected average speed;25 determining an energy requirement for each route segment independence on the energy information, the projected average speed, and the projected deviation from the projected average speed for the route;outputting an energy requirement signal indicative of the energy requirement for the route,30 wherein the route data signal comprises data on interruptions in the route, whereinan interruption corresponds to a location when the vehicle may be required to stop or decelerate, and wherein the projected deviation is based on the number of interruptions.

10. A method as claimed in claim 9, wherein the projected deviation for a segment is a function of the total number of interruptions.10 03 2511. A method as claimed in claim 10, wherein the energy requirement, NE, for a segment 5 of the route is determined using the formula:NE = OE / (Factor A n),where:OE is the energy requirement determined for the projected average speed;Factor is a number close to, but less than, one; and10 n is the number of interruptions determined for the route..

12. A method as claimed in any of claims 9 to 11, wherein the route comprises a plurality of route segments, wherein each route segment corresponds to a portion of the route, and wherein the route data signal is indicative of the projected average speed for each route 15 segment.

13. A method as claimed in claim 12, wherein the route segments of the route are substantially contiguous, and correspond to substantially the complete route between first location and the second location.2014. A method as claimed in any of claims 9 to 13, comprising receiving a driver style signal indicative of a driving style associated with the present driver of the vehicle, and determining the energy requirement for each route segment in dependence on driving style, the energy information and the projected representative speed for that segment 2515. A non-transitory, computer-readable storage medium storing instructions thereon that, when executed by one or more electronic processors, causes the one or more electronic processors to carry out the method of claim 9 to 14.30

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