GB2483454A

GB2483454A - Electric vehicle range control

Info

Publication number: GB2483454A
Application number: GB1014884.9A
Authority: GB
Inventors: John William Anderson Paterson; Arthur Thomas Wolstenholme; Timothy Peter Martin
Original assignee: LIGHTNING CAR Co Ltd
Current assignee: LIGHTNING CAR Co Ltd
Priority date: 2010-09-08
Filing date: 2010-09-08
Publication date: 2012-03-14
Anticipated expiration: 2030-09-08
Also published as: GB201014884D0; GB2483454B

Abstract

A method of controlling the operation of an electric motor vehicle, comprising the steps of receiving location data 401 indicating the present location of the vehicle and receiving command data 402 identifying a proposed destination for the vehicle. The energy requirement 404 for the vehicle to be driven from the present location to the proposed destination is calculated. If batteries contained within the vehicle cannot provide sufficient energy 405 to satisfy the energy requirement, operation of the vehicle is modified 406. The location data is preferably received from a global positioning sensor (GPS). Modification of the operation of the vehicle may include reducing the maximum speed or disabling auxiliary equipment. Also claimed is a processing device in an electric vehicle for carrying out the claimed method.

Description

Range Control

CROSS REFERENCE TO RELATED APPLICATIONS

This application represents the first application for a patent directed towards the invention and the subject matter.

S BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to controlling the operation of an electric motor vehicle.

2. Description of the Related Art

Conventional motor vehicles using petroleum-based products as a fuel are presented with an infrastructure of filling stations in most countries such that the amount of fuel that may be carried initially does not place any constraints upon the total range of any particular journey. Even with vehicles having modestly sized fuel tanks, it is likely that for any particular journey, a driver will pass several filling stops before the vehicle actually runs out of fuel.

Furthermore, in modern vehicles indicators are provided showing the amount of fuel remaining and in some vehicles this may even extend to an indication of range before further fuel is required.

It is also known that in many modern vehicles fitted with satellite navigation systems, it would be possible for a driver to compare the distance remaining to the end of the journey (with reference to the satellite navigation system) with the range available, from the fuel indicator system. A driver is therefore often aware as to whether it is necessary to stop at a filling station and the driver may also safely assume that a filling station will be available.

Satellite navigation systems are also known which provide an indication of filling stations within the area once the remaining level of fuel reaches a pre-determined level.

Traditionally, electric vehicles are used to perform routine operations usually within a confined geographical area. In many situations, recharging is provided from a single facility, at the driver's base or at the driver's home and the vehicle may be recharged routinely overnight. Thus, for applications of this type, working within a warehouse or making modest journeys within city boundaries, the overall distance and energy requirements of the vehicle remain relatively constant and problems in terms of range generally do not exist.

A problem does exist in terms of using electric vehicles to perform many of the functions taken for granted in the hydrocarbon environment, such as travelling significant distances and possibly requiring additional energy before turning back to base. Presently, recharging stations are limited therefore were electric vehicles to be used for substantial journeys, there is a significant risk that the vehicle could exhaust its battery supply and thereby effectively become stranded.

BRIEF SUMMARY OF THE INVENTION

According to an aspect of the present invention, there is provided a method of controlling the operation of an electric motor vehicle, comprising the steps of receiving location data indicating the present location of the vehicle, receiving command data identifying a proposed destination for the vehicle, calculating the energy requirement for the vehicle to be driven from said present location to the proposed destination and modifying the operation of the vehicle if batteries contained within the vehicle cannot provide sufficient energy to satisfy said energy requirement.

BR1EF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS Figure 1 shows an embodiment of the present invention directed towards controlling the operation of an electric motor vehicle; Figure 2 shows communication with the vehicle via mobile telephony; Figure 3 shows an example of a processing system for a vehicle; Figure 4 shows procedures performed by the processor shown in Figure 3; Figure 5 shows an example of procedures for modifying the operation of the vehicle; Figure 6 shows a table populated by procedures invoked for looking at alternative routes; Figure 7 shows a table populated by the process of Figure 5 concerning equipment savings; and Figure 8 shows a first table considering speed reduction and a second table considering acceleration reduction.

DETAILED DESCRIPTION OF EMBODIMENTS

Figure 1 An embodiment of the present invention, shown in Figure 1, is directed towards controlling the operation of an electric motor vehicle 101, in which location data is received identifying the present location of the vehicle. As detailed in Figure 3, a processor may receive location data via a global positioning satellite system or similar external infrastructure for providing a geographical location.

Vehicle 101 receives command data identifying a proposed destination for the vehicle. As shown in Figure 1, this command data may be received in conventional fashion by manually interfacing with a touch screen 102 of what may appear as a substantially conventional satellite navigation system. Thus, in the embodiment, the system is presented with an indication of the current location and an indication of a proposed destination, from which it is possible to calculate a route using known satellite navigation heuristics.

Where the embodiment of Figure 1 differs from that of conventional satellite navigation systems is in that the system calculates the energy requirement for the vehicle to be driven from the present location to the proposed destination. It will then modify the operation of the vehicle if batteries contained within the vehicle cannot provide sufficient energy to satisfy the energy requirement.

Figure 2 An embodiment of the present invention is directed towards a high performance electric vehicle with sophisticated data processing capabilities (detailed in Figure 3) contained on board. It is therefore possible for this data processing facility to extend the capabilities of the vehicle and to enhance the overall driver experience. In the example of Figure 2, communication with the vehicle 101 is made possible via mobile telephony, using a conventional mobile cellular telephone 201. In the embodiment, the vehicle (or more correctly the processing capability within the vehicle) recognises the source of the voice and is thus able to distinguish a particular driver from a set of drivers regularly using the vehicle. Furthermore, in an embodiment this approach could be extended further to the extent that the vehicle would be disabled were the voice not recognised as an authorised driver.

Upon recognising the source of the voice as that belonging to an authorised driver, the vehicle adjusts driver comfort devices (steering wheel extent and tilt, seats, mirrors and pedals, etc.) into a position preferred by that driver.

Using mobile cellular telephone 201 it is possible to identify destinations to the vehicle by a process of speech recognition. In an embodiment, the vehicle is preloaded with voice templates used to identify destinations for which journeys are made regularly. A voice command of this type would be compared against this stored list and in an embodiment a hand shaking operation is performed in that a verbal acknowledgement is returned back to the driver. The driver would then be in a position to confirm (verbally) as to whether the correct destination had been identified or, alternatively, to repeat the process.

In an alternative embodiment, the speech recognition system is not provided with pre-recorded templates but relies on a more sophisticated process of speech recognition allowing the destination to be compared against an index of destinations stored within the satellite navigation system. A driver could, for example, provide a postcode to the satellite navigation system without this postcode having previously been identified as a preferred destination. The satellite navigation system could then return a more detailed account of the address selected, seek confirmation as to whether this is correct and possibly record the destination for future selection in order to enhance the selection process. Thus, the speech recognition system in combination with a satellite navigation system could be configured to perform a learning process based on an assumption that a driver will tend to make multiple journeys to the same destination or on the assumption that a driver often makes journeys to a particular geographical area.

Using mobile telephony, it is not necessary for the driver to be in the vicinity of the vehicle in order for these commands to be issued. An option would be for the vehicle to remain at a charging station such that, during the charging process, it would be possible for the driver to make several enquiries as to whether a particular journey was possible. In response to these enquiries and as described with respect to Figures 4 through 8, the vehicle may return audio information to the effect that the journey is possible in a fully functional mode and that it is currently available for use. The driver could then move to the vehicle, enter the vehicle and drive away with the satellite navigation fully functional and in the reassurance that the vehicle has sufficient energy on board in order to complete the journey. In a further enhancement to the embodiment, it would also be possible to confirm whether the journey is of a one way nature or whether it is necessary to make a return trip without undergoing a further charge.

Situations will also arise where it is determined that insufficient charge is available for the journey to be made. Under these circumstances the vehicle may return information to the effect that further charging will be required before the journey is possible. The vehicle may also return information to the effect that the journey is only possible if further stops are made for a recharging operation to be performed during the journey. Such an acknowledgement will be made only if the vehicle is aware as to where these stops may be made.

If the vehicle determines that it is not possible to make the journey without additional charging and the system is unaware as to where charging stations are located, the journey will be considered impossible and the driver will be positively deterred. In an extreme embodiment, operation of the vehicle will be totally disabled until a new destination has been identified that is considered within the capabilities of the vehicle's batteries or within the capability of the vehicle's batteries on the assumption that a recharging process takes place at a known recharging location.

In marginal situations, the vehicle will still not commit to the journey until it can be reassured that the journey is within the range of the vehicle's Is capabilities. Under these circumstances sophisticated modifications are made either to internal equipment as detailed in Figure 7 or to the performance of the vehicle itself, as detailed in Figure 8.

Figure 3 The vehicle includes a processing system, an example of which is shown in Figure 3. A processor 301 is configured to control the operation of the electric vehicle and is interfaced to a first receiving device 302 for receiving location data indicating the present location of the vehicle. Thus, in an embodiment, the first receiving device may be a GPS (Global Positioning Satellite) subsystem or any subsystem providing location data indicating the current location.

A second receiving device receives command data identifying a proposed destination for the vehicle. This may take the form of a graphical interface 102 (as described in Figure 1) or an audio interface receiving audio communications via a mobile telephony module 303, such as a GSM module or a module capable of digital communications using any international communication standard.

The processing device 301 calculates the energy requirement for the vehicle to be driven from the present location to the proposed destination and modifies the operation of the vehicle if batteries 304 contained within the vehicle cannot provide sufficient energy to satisfy the energy requirement. In the embodiment, the processing device is resident within an electric high performance sports car where it may be assumed that optimum performance is required subject to sufficient energy range being within the batteries in order for the journey to terminate at the required destination without exhausting the battery supply before the destination is reached.

The processor 301 is required to perform many functions that are similar to the operations performed by a conventional satellite navigation system. Known satellite navigation procedures perform heuristics in which weightings are given to particular sections of road, topological paths are selected as candidates and a particular route is then chosen based on the selection that provides either the shortest distance or the shortest travel time.

In the present embodiment, similar constraints are adopted but to this mix of time and distance a further parameter is included concerning the overall energy requirement. Thus, in many situations, it may be assumed that a faster route will require more energy than a direct route. However, further constraints may be present such as steep gradients and the inclusion of many urban areas where there is a high probability that many stopping and starting operations will be required.

The processor 301 therefore receives this geographical data from an appropriate data storage device 305. In an embodiment, it is also possible for the processor to receive live data, identifying traffic jams and road works for example, so that these constraints may also be brought into the overall process for calculating energy demand.

As previously described, the processor makes an assessment as to whether the journey is possible and this information is brought to the attention of the driver. However, in addition to this, the processor 301 may also modify the operation of the vehicle so as to further reduce energy demand and therefore make the commanded destination possible. The processor 301 therefore communicates with a drive management system 306 which in turn has control over substantially all operations within the vehicle itself.

Furthermore, during servicing and maintenance, it is possible for technicians to be given access to processor 301 via an external interface 307.

Figure 4 Procedures performed by processor 301 are detailed in Figure 4. At step 401 location data is received from the GPS module 302 in order to identify the current location of the vehicle.

At step 402 command data is received identifying the proposed destination, which may be received from the graphical interface 102, via mobile telephony module 303 or via any other appropriate data input device.

At step 403 the route is navigated using substantially conventional satellite navigation heuristics. These may identify several possibilities, of which one may be the fastest route, one may be the shortest route and a third may represent the most energy conserving route. In an embodiment, it may be possible for a driver to select a default, possibly the fastest route although this may be modified to the most energy conserving route if range becomes an issue. Thus, at step 404 a calculation is performed to determine the energy requirement.

At step 405 a question is asked as to whether sufficient energy is available and if answered in the affirmative, the processor 301 facilitates driving to the location at step 407. However, if the question asked at step 405 is answered in the negative, to the effect that sufficient energy may not be available, operation modifications are invoked at step 406.

Thus, in practice, an identification has been made of one of three possible states. In a first state, the proposed destination is well within range and full vehicle performance may be placed at the disposal of the driver thereby facilitating the drive to the location. In a second state, a determination may be made to the effect that it is not possible to reach the destination under any foreseeable circumstances. Thus, in the second state operation of the vehicle may be prevented until an alternative destination has been selected.

In a third state, sufficient range may be available in order to reach the destination but in order to do so modifications will be required. The driver must then accept these modifications in order that the system may provide full reassurance to the effect that the destination is within range. Thus, the system is configured such that the vehicle commits to a particular journey and once committed will take all necessary measures in order to ensure that the driver arrives at the destination. If it is not possible for the vehicle to make this commitment, the journey may be prohibited or the system may convey information to the driver to the effect that the driver is now assuming full responsibility.

Figure 5 An example of procedures 406 for modifying the operation of the vehicle are illustrated in Figure 5.

Upon entering process 406, a determination has been made to the effect that the vehicle does not have sufficient energy, under full performance operation, to reach the destination using the preferred route. At step 501 further investigations are made to identify alternative routes. Under these procedures, the fastest route and/or the shortest route may be rejected in preference for a route that requires less energy. This may avoid gradients and/or avoid built up areas. It may not represent the quickest way of reaching the destination but it may make reaching the destination possible without requiring the batteries to be recharged.

A further consideration taken into account during process 501 is to identify the possibility of the vehicle being recharged while mid-journey. Thus, on the assumption that electrical charging stations of the appropriate type are not abundant, it may be necessary for the vehicle to make a detour and upon reaching the recharging station, it may be necessary for the vehicle to remain at this station for a period of time while the recharging process takes place.

However, again, such a detour may convert an impossible route into a possible route, assuming the driver is prepared to accept the inconvenience.

Having considered route options, a question is asked at step 502 as to whether sufficient energy is now available. When answered in the negative, procedures will be considered at step 503 directed towards making energy savings by disabling equipment contained within the vehicle, as detailed with reference to Figure 7.

At step 504 a question is again asked as to whether sufficient energy is available and when answered in the negative procedures are invoked at step 505 to consider whether it is possible to make engine savings. Examples of engine savings are detailed in Figure 8 in which the overall performance of the vehicle is reduced. For a performance vehicle such as an electric sports car, restraining the full capabilities of the car is often seen as a last resort but again this may be the only option in terms of making the journey a realistic proposal.

Having considered engine saving possibilities a question is again asked at step 506 as to whether sufficient energy is available. When answered in the negative, a demand is made of the system for additional charging to be invoked at step 507 such that, taking all the measures identified above or a particular selection of these measures and ensuring that the vehicle is fully charged, it may be possible for the journey to be completed.

At step 508 a question is again asked as to whether sufficient energy is available and if answered in the affirmative, the drive is facilitated at step 407.

However, having considered all of the possibilities for saving energy, if the question asked at step 508 is again returned in the negative, the route is disabled at step 509 and the driver is invited to make an alternative selection.

Figure 6 Procedures invoked at step 501 for looking at alternative routes results in a table 601 being populated.

In this example, a first column 602 identifies the nature of the route and a second column 603 identifies the amount of energy required for that particular route.

In this example, a fast route is populated at row 604 and an energy value is calculated and recorded in record 605.

This process is repeated at row 606 with an energy value 607 being recorded for the most direct route.

In this example, the most energy efficient route is identified as the level route (lacking gradient) at row 608 with its energy value being recorded at 609.

The system then goes on to identify completing the route with one stop, at row 610 with an energy value being recorded at 611 representing the amount of energy required for the most energy intensive leg of the two legs.

A similar exercise is performed at row 612, in which two stops are made resulting in the journey being broken into three legs. Again, an energy value is recorded at step 613 for the leg requiring the most amount of energy.

From the energy column 603 it is possible to identify which, if any, of the options allows the route to be completed. Thus, for the purposes of this example, it may be assumed that anything short of energy value 611 would not allow the journey to be completed therefore the process has concluded that it is only possible to perform the journey if there is at least one stop.

Several issues may be analysed in order to identify the most energy efficient route. Some of these constraints will remain fixed while others will be transient and will rely upon real time data. Thus, less congested roads could be selected or roads with fewer speed restrictions could be selected.

Roadwork's and other temporary features could be avoided because a requirement to perform many stops and starts could significantly add to the amount of energy required in order to complete the journey.

Figure 7 Process 503 concerning equipment savings results in the population of a table 701, as shown in Figure 7.

A first column 702 identifies the nature of the equipment and a second column 703 identifies a percentage energy saving when the item of equipment is disabled.

At row 704 the air conditioning system is considered and an energy saving percentage is recorded at 705.

The air conditioning system could be a climate control system and could include heating devices for heating an incoming air stream or cooling the incoming air stream dependent upon ambient conditions. In an embodiment, the operation of an air conditioning system is reversed to provide heating by heat pump technology. However, in some embodiments, simple resistive heating systems may be advantageous if they are relatively lighter and are only required for relatively short periods of time during an initial start-up.

Further resistive heating components may be provided, such as seat heaters and mirror heaters which again could be disabled in order to make power savings.

At row 706 the lights are considered and again a percentage saving is recorded at 707. It is also appreciated that additional processing will be required to determine whether it is possible to drive the vehicle without lights, depending upon time of day and the intended period within the day during which the journey time is anticipated. The provision of interior lighting may also be considered, along with the brightness control for touch screens provided within the vehicle.

At row 708 a power amplifier for the audio system is considered and again percentage savings are recorded at 709. In this example, the power amplifier relates to relatively high audio outputs which in many situations will not be required. Other entertainment systems may be provided such as a television receiver and systems for replaying recorded video material. A sound emitter may be included for generating simulated engine noises (possibly as a warning to pedestrians) and again the system may be disabled. In an embodiment, the sound emitting system is first of all disabled in non-builtup areas, so as to remain available in areas where there is a greater likelihood of pedestrians being present. This information would be derived from the satellite navigation subsystem.

At row 710 all audio equipment is considered and again an energy saving is recorded at 711.

Finally, in this example, telephony is considered at 712 and again a percentage saving is recorded at 713.

In an embodiment, it will be possible for a driver to identify internal equipment considered necessary and that considered optional. Thus, some drivers may have expressed a preference for retaining the air conditioning system, whereas other drivers may have expressed preferences for the audio system or the telephony system.

Figure 8 For a performance vehicle, many drivers would consider a limitation to the vehicle's performance to be the last measure that could be tolerated as a mechanism for saving energy. However, it is appreciated that this is likely to be the most successful mechanism for converting an impossible journey into a possible journey. In this example, engine savings procedures 505 result in the population of a first table 801 that considers speed reduction and a second table 802 that considers acceleration reduction.

At row 803 a ninety percent speed reduction is identified and an estimated percentage saving of stored energy is recorded at 804. Thus, under this proposal, the maximum speed available would be restrained to ninety percent. Thus, for example, a vehicle having a maximum speed of 100 kph would be restricted to a maximum speed of 90 kph.

Similarly, an eighty percent speed reduction is identified at row 805 with the resulting estimated percentage energy saving being recorded in 806.

Similarly, row 807 identifies a seventy percent reduction and row 808 records a sixty percent reduction. These result in savings recorded at 809 and 810 respectively.

In addition to restricting the maximum speed, it is also appreciated that savings may be obtained by reducing acceleration. In table 802 a column 811 records acceleration reduction figures and a column 812 records percentage savings.

In this example, a row 813 identifies an acceleration reduction to ninety percent of maximum and an estimated energy saving is recorded at 814.

Similarly, column 815 identifies an acceleration reduction to eighty-five percent with the energy saving being recorded at 816. In this example, rows 817, 818 and 819 identify acceleration reductions to eighty percent, seventy-five percent and seventy percent respectively of a maximum acceleration available, with the resulting energy savings being recorded at 820, 821 and 822 respectively.

In an embodiment, the system is aware of the locations of recharging stations and is also aware of the maximum power output from these recharging stations. Thus, it is possible to calculate the time required in order to achieve a complete recharge or in order to achieve a sufficient recharge in order to complete the journey or complete the next leg of the journey. The system is provided with a real time clock so that a driver may be notified, possibly by SMS, to the effect that a sufficient charge has been achieved or that the battery is fully charged.

In an embodiment, while the vehicle is being driven, the driver may be presented with an updated estimated time of arrival and a notification to the effect that a recharge stop will be required or a reassurance to the effect that a recharge will not be required and that the vehicle is capable of reaching the intended destination. Thus, this information can be updated in real time such that the system will adapt should unexpected situations arise that cause the vehicle to be delayed or re-routed.

Claims

Claims 1. A method of controlling the operation of an electric motor vehicle, comprising the steps of: receiving location data indicating the present location of the vehicle; receiving command data identifying a proposed destination for the vehicle; calculating the energy requirement for the vehicle to be driven from said present location to the proposed destination: and modifying the operation of the vehicle if batteries contained within the vehicle cannot provide sufficient energy to satisfy said energy requirement.
2. The method of claim 1, wherein said electric motor vehicle is a high performance sports car.
3. The method of claim 1, wherein said location data is received from a global positioning satellite (GPS) system.
4. The method of claim 1, wherein said command data is received from a human interface device.
5. The method of claim 4, wherein said human interface device is an audio device and said command data is received via a voice recognition module.
6. The method of claim 1, including a processing device and a data storage device for providing geographical data to said processing device, wherein said processing device is configured to perform said step of calculating the energy requirement.
7. The method of claim 1, wherein said data storage device also includes topographical data identifying gradients that affect energy consumption.
8. The method of claim 7, wherein said data storage device also includes the locations of recharging stations.
9. The method of claim 1, wherein said step of modifying the operation of the vehicle includes totally disabling the operation of the vehicle on the basis that insufficient energy is available.
10. The method of claim 1, wherein said step of modifying the operation of the vehicle includes invoking measures for reducing power consumption during the journey.
11. The method of claim 10, wherein the measure of reducing the maximum available speed is invoked to reduce power consumption.
12. The method of claim 10, wherein the measure of disabling auxiliary equipment is invoked to reduce power consumption.
13. The method of claim 10, wherein the measure of invoking a less power demanding route is invoked in preference to the fastest route to reduce power consumption.
14. The method of claim 10, wherein the measure of invoking a mandatory re-charging stop is invoked as a modifying operation.
15. The method of claim 1, wherein said step of modifying the operation of the vehicle includes providing an indication of available additional driving distance availabie after reaching the proposed destination.
16. In an electric vehicle, a processing device configured to control the operation of the electric vehicle, comprising: a first receiving device for receiving location data indicating the present location of the vehicle; a second receiving device for receiving command data identifying a proposed destination for the vehicle; wherein said processing device calculates the energy requirement for the vehicle to be driven from said present location to the proposed destination and modifies the operation of the vehicle if batteries contained within the vehicle cannot provide sufficient energy to satisfy said energy requirement.
17. The processing device of claim 16, wherein said electric motor vehicle is a high performance sports car.
18. The processing device of claim 16, wherein said location data is received from a global positioning satellite (GPS) system.
19. The processing device of claim 16, wherein said command data is received from a human interface device.
20. The processing device of claim 19, wherein said human interface device is an audio device and said command data is received via a voice recognition module.