WO2017207982A1

WO2017207982A1 - Vehicle sleep mode

Info

Publication number: WO2017207982A1
Application number: PCT/GB2017/051544
Authority: WO
Inventors: Mirek LESZCZYNSKI
Original assignee: Arrival Limited
Priority date: 2016-05-31
Filing date: 2017-05-31
Publication date: 2017-12-07
Also published as: GB2551312B; GB2551312A; GB201609483D0; EP3463964A1

Abstract

A method, and apparatus, and a system for controlling a power-saving mode of a vehicle. The system comprises a detector for detecting a presence of a user within the vehicle; a controller for determining whether the user is present within the vehicle based on detection of the sensor, and for controlling the vehicle to enter the power- saving mode if it is determined that the user is not present within the vehicle. When the vehicle enters the power-saving mode, power consumption of at least one of a vehicle component is minimised, hence the efficiency of power management within the vehicle is increased.

Description

Vehicle Sleep Mode

Field

This specification relates to controlling an operational mode of a vehicle. Specifically, the specification relates to controlling a power-saving mode and provides for efficient energy management in vehicles, such as electric vehicles.

Background

Electric vehicles take a variety of forms, namely pure electric, i.e. where the only source of power is a battery, parallel hybrid, i.e. where an internal combustion engine or battery may drive the wheels, or series hybrid vehicles, i.e. where a secondary power source, such as a range extender, recharges an on-board battery. It is noted that the term "electric vehicle(s)" is used herein to include different types of electric vehicles including pure electric, parallel hybrid, and series hybrid.

In most electric vehicles, there is provided a power source in the form of a self- contained battery. The battery typically requires charging from conventional power outlets or dedicated charging stations and the charging process can take hours. Hence, there is a need for efficiently managing the power consumption of these vehicles in order to minimise the frequency that the vehicle requires charging.

Summary

In a first aspect, this specification describes a method for controlling a power-saving mode of a vehicle, the method comprising: detecting a presence of a user; determining whether the user is present within the vehicle based on the detection, and controlling the vehicle to enter the power-saving mode if it is determined that the user is not present within the vehicle, wherein entering the power-saving mode includes minimising power consumption of at least one of a vehicle component. The at least one vehicle component may be an auxiliary power unit arranged to generate electricity for charging a power storage unit of the vehicle.

The auxiliary power unit may comprise a range extender, optionally wherein the range extender is an engine motor. The method may further comprise comparing a battery level of the vehicle with a first threshold during the power-saving mode; and transmitting a warning notification when the battery level is lower than the first threshold. The warning notification may be transmitted through a cloud storage system to at least one of: a mobile device of the user and a manger of the vehicle.

The method may further comprise comparing the battery level of the vehicle with a second threshold during the power-saving mode; and switching on the auxiliary power unit when the battery level is lower than the second threshold.

Detecting the presence of a user may comprise: receiving location information of the vehicle and location information of the user; and detecting a presence of the user within the vehicle when it is determined that the vehicle and user are within a predetermined distance of each other.

The location information of the user is received from a mobile tag.

Detecting the presence of a user may comprise: detecting a pressure on a driver seat of the vehicle; and detecting a presence of the user within the vehicle when the pressure on the driver seat exceeds a predetermined value.

It may only be determined that the user is not within the vehicle when the presence of the user is not detected for a predetermined time period.

In a second aspect, this specification describes apparatus comprising means for performing a method according to the first aspect.

In a third aspect, this specification describes computer-readable instructions which, when executed by computing apparatus, cause the computer apparatus to perform a method according to the first aspect.

In a fourth aspect, this specification describes a system controlling a power-saving mode for a vehicle, the system comprising: a detector arranged to detect a presence of a user within the vehicle; a controller arranged to determine whether the user is present within the vehicle based on detection of the sensor, and to control the vehicle to enter the power-saving mode if it is determined that the user is not present within the vehicle; wherein entering the power-saving mode includes minimising power consumption of at least one of a vehicle component. The system may comprise a power storage unit, and wherein the at least one of a vehicle component is an auxiliary power unit arranged to generate electricity for charging the power storage unit.

At least one of a vehicle component may comprise at least one of: an air conditioning unit, a stereo unit, a climate control unit, a GPS unit, a display unit, and/or a lighting unit.

Brief Description of the Drawings

For a more complete understanding of the methods, apparatuses, and systems described herein, reference is now made to the following descriptions taken in connection with the accompanying drawings in which:

Figure ι is a block diagram illustrating a system for controlling a sleep mode for a vehicle according to an exemplary embodiment;

Figure 2 is a graph illustrating battery level of a vehicle against time, according to an exemplary embodiment;

Figure 3 is a flowchart schematically illustrating various functionalities which may be provided by the system of Figure l, according to an exemplary embodiment; and Figure 4 is another flowchart schematically illustrating various functionalities which may be provided by the system of Figure 1, according to an exemplary embodiment.

Detailed Description

Embodiments of the invention provide for more efficient energy management of a vehicle, which is particularly beneficial for vehicles of the electric or hybrid type.

Embodiments of the invention limit power consumption, e.g. by power generators and/or accessory components of the vehicle, when the user (e.g. a driver) of the vehicle is not present in the vehicle. In recent years, electric vehicles have been widely adopted for commercial uses, for example as delivery vans and trucks. These electric delivery vehicles are typically parked for a short period of time within the vicinity of the delivery address such that delivery personnel can perform delivery of goods. When an electric vehicle is used for commercial delivery purposes, the vehicle is so quiet that sometimes the driver (e.g. delivery personnel) may easily forget to switch off the power to the drivetrain when leaving the vehicle. The delivery person may alternatively deliberately choose not to switch off the power, especially when the delivery person only intends to park the vehicle for a short period of time. This is in some ways equivalent to leaving on the 'ignition' in a conventional motor vehicle. Additionally or alternatively, accessory components of the vehicle, such as an air conditioning system and/or a stereo unit, may be left switched on whilst the driver is away from the vehicle. This causes power consumption from the battery in the vehicle. The embodiments described below provide an apparatus and method for reducing this power consumption and thereby efficiently managing the available power in the electric vehicle. In the case of an electric vehicle comprising a range extender unit, such as an internal combustion engine configured to supply power for recharging one or more high voltage batteries of the electric vehicle, the embodiments described below also provide an apparatus and method for managing use of the range extender unit in the 'parked' scenarios described above. In particular, the embodiments reduce the number of situations in which the range extender unit may automatically start, or otherwise switch on, when the vehicle is temporarily parked. This is advantageous because the automatic starting of a range extender unit in a parked, apparently dormant vehicle may alarm, or at least startle, those in the vicinity of the vehicle. This is particularly the case when the driver of the vehicle is not present.

Figure l is a block diagram illustrating a system for controlling a power-saving mode for a vehicle according to an exemplary embodiment. For the sake of brevity, this mode is referred to below as a sleep mode. As shown in Figure 1, the system 1 comprises a vehicle 100, a cloud network 200, such as a remote server, and a mobile tag 300. A user 400 is also illustrated in Figure 1. In this embodiment, the vehicle 100 is an electric vehicle including an electric motor unit (not shown in the drawing). The cloud network 200 comprises a cloud storage unit, such as a server. Also, in this embodiment, the user 400 may be the driver of the vehicle 100. The vehicle 100 comprises a detection system no, a control unit 120, a power storage unit 130, an auxiliary power unit (APU) 140, a transmitting unit 150, and an accessory unit 160. The detection system 110 is arranged to detect a presence of a user of the vehicle. In this embodiment, the detection system 110 comprises a sensor. The sensor may be at least one of: a pressure sensor, a belt buckle sensor, and a mobile tag sensor. In this embodiment, the sensor is a mobile tag sensor that is located within the vehicle. As shown in Figure 1, the system 100 further comprises a mobile tag 300 which can be detected by the mobile tag sensor when the mobile tag 300 is within a predetermined vicinity of the mobile tag sensor. For example, the mobile tag sensor may be configured to detect a presence of the mobile tag 300 within a 2m radius of the mobile tag sensor (which is located in the vehicle 100). The mobile tag 300 in this embodiment is comprised in a smartphone, which is presumed to be carried with the user 400 when the user is away from the vehicle 100. Therefore, the location of the mobile tag 300 is indicative of the location of the user 400. The smartphone may be equipped with Bluetooth technology and/or other suitable wireless communication systems such that the mobile tag sensor is able to detect when the smartphone is within a predetermined range of the mobile tag sensor. Furthermore, a smartphone application may be installed at the smartphone in this embodiment. The functionalities of the smartphone application will be described in further detail below with regarding to receiving a warning notification from the transmission unit 150. The smartphone application may optionally comprise the mobile tag 300, implemented in the application software.

The control unit 120 is arranged to determine whether the user is present within the vehicle based on detection of the detection system 110, and to control the vehicle 100 to enter a sleep mode when it is determined that the user is not present within the vehicle. In the present embodiment, as mentioned above, the detection system 110 is configured to detect a presence of the mobile tag 300 within a 2m radius of the vehicle. The control unit 120 in this embodiment is configured such that if the mobile tag 300 is not within a 2m radius of the vehicle 100 for a predetermined time period, it is determined that the user 400 is not present within the vehicle. By introducing this predetermined time period, the system 1 can ensure that the user 400 is genuinely away from the vicinity of the vehicle 100. Once it is determined that the user 400 is not within the vehicle 100, the control unit 120 controls the vehicle 100 to enter a sleep mode. In the sleep mode, power consumption is minimised for one or more vehicle components. Specifically, in the present embodiment power consumption is minimised for at least the accessory unit 160. The accessory unit 160 will be described in further detail below. Additionally or alternatively, if the vehicle 100 comprises an auxiliary power unit 140, as referred to above, activation of the auxiliary power unit 140 to charge the power storage unit 130 is strictly limited in the sleep mode. In the sleep mode, the auxiliary power unit 140 is activated only in very limited circumstances so as to prevent startling those in the vicinity of the vehicle 100.

The power storage unit 130 is arranged to provide power to a variety of components of the vehicle. The power storage unit 130 in the present embodiment comprises one or more self-contained batteries, and is electrically connected to components of the vehicle, including the accessory unit 160, to provide electrical power.

The auxiliary power unit 140 is arranged to generate electricity for charging the power storage unit 130. In the present embodiment, the auxiliary power unit 140 comprises a range extender which is arranged to drive an electric generator unit (not shown in the drawing) to charge the power storage unit 130. The range extender comprises an engine unit (e.g. an internal combustion engine) and an alternator unit for converting mechanical energy from the engine unit to electrical energy for charging the power storage unit 130. The auxiliary power unit 140 is controlled by the control unit 120 to provide electrical power to the power storage unit 130, as desired.

As described above, the control unit 120 is arranged to minimise power consumption of at least one of the vehicle components during the sleep mode. In the present embodiment, in addition to minimising the power consumption by reducing power consumption of at least one of the vehicle components, the control unit 120 is arranged to compare the battery level of the vehicle 100 with a first threshold during the sleep mode. Battery level in the present embodiment refers to the battery level of the power storage unit 130. As explained below, comparison of the battery level with one or more set battery thresholds ensures that in the sleep mode the state of the battery is not allowed to decline to a condition which is undesirable due to deliberate inactivation of the auxiliary power unit 140. Such an undesirable battery level might be, for example, a charge level that would be insufficient to power the drivetrain when the driver returns to the vehicle. As explained below, in the event that the battery level were to approach such a condition, the vehicle 100 is configured to activate the auxiliary power unit 140 to recharge the battery, even when the vehicle 100 is in the sleep mode.

In this embodiment, the first threshold referred to above is a battery level calculated by the control unit 120. The threshold is calculated based on a current power

consumption rate of the vehicle 100, such that it corresponds to a discharge level which will be reached a set time period before the battery level decreases to a second (lower) threshold. In this embodiment, the set time period is 15 minutes, but it will be appreciated that other time periods are equally possible. In other words, based on a detected/ measured power consumption rate of the vehicle 100, the first threshold is calculated by the control unit 120 such that it corresponds to a battery level which will be reached 15 minutes before the battery level of the vehicle 100 drops to the second predetermined threshold.

If it is determined by the control unit 120 that the battery level of the vehicle 100 is lower than the first threshold, the control unit 120 is arranged to control the transmitting unit 150 to transmit a warning notification. In the present embodiment, the warning notification is a signal transmitted from the transmitting unit 150 of the vehicle 100 via the cloud network 200 to the mobile tag 300. As described above, the mobile tag 300 in this embodiment is comprised in a smartphone at which a smartphone application is installed. The mobile tag 300 is configured to receive the warning notification signal via the cloud network 200 from the transmitting unit 150.

Subsequent to receiving the warning notification signal from the transmitting unit 150, the mobile tag 300 is configured to present the warning notification to the user 400. In the present embodiment, the warning notification is presented to the user 400 in one or both of audio and visual formats (e.g. a "beep" notification sound accompanied by a push notification at a screen of the smartphone). The user 400 is therefore alerted that the battery level of the vehicle 100 is lower than the first threshold and can decide whether to return to the vehicle 100, and whether to further switch on the auxiliary power unit 140 to charge the power storage unit 130. In the present embodiment, the control unit 120 is further arranged to compare the battery level of the vehicle 100 with the second threshold, as described above. In this embodiment, the second threshold has a lower value than the first threshold. If the battery level of the vehicle 100 is lower than the second threshold, the control unit 120 is arranged to control the auxiliary power unit 140 to switch on. By switching on the auxiliary power unit 140 once the battery level becomes lower than the second threshold, the system 1 prevents the battery level from reaching a critical level at which the power storage unit 130 may become temporarily or permanently damaged, and/or at which the battery level is no longer sufficient to drive the electric drivetrain of the vehicle (not shown in the drawing) with enough power to propel the vehicle 100.

The accessory unit 160 in this embodiment comprises a number of automobile accessory components including: an air conditioning unit, a stereo unit, a climate control unit, a GPS unit, a display unit, and/or a lighting unit. When power

consumption is minimised for the accessory unit 160, one or more of these automobile accessory components are switched off or controlled so as to be in a low power consumption mode. As an example, the brightness or visual effects of the display unit of the accessory unit 160 may be reduced in its low power consumption mode. Figure 2 is a graph illustrating the battery level of a vehicle against time, according to an exemplary embodiment. Specifically, the graph in Figure 2 illustrates variation in a battery level of the vehicle 100 of Figure 1 against time.

As shown in the graph of Figure 2, the battery level of the vehicle 100 is represented in the y-axis of the graph while elapsed time (labelled as "time" in Figure 2) is represented in the x-axis. In the x-axis, a plurality of points of time are labelled respectively as "t=o", "A", "B", "C", and "D". As will be explained in further detail in the following, these points of time correspond to a plurality of events including: initial state, enter sleep mode, battery level decreasing to the first threshold, battery level decreasing to the second threshold, and the battery level increasing to the first threshold from the second threshold.

From t=o to point A, the battery level of the power storage unit 130 decreases in a manner corresponding to an initial power consumption rate of the vehicle. In this embodiment, t=o represents a point in time at which the vehicle is in a state where power is switched on, for example when the vehicle is running, and the vehicle components are switched on. This causes a normal rate of power consumption of the power storage unit 130. The battery level of the power storage unit 130 decreases at a relatively steady rate between t=o and point A due to the power consumption by the essential vehicle components, such as the drivetrain, as well as those included in the accessory unit 160.

At time point A, it is determined by the control unit 120 that the user 400 is not present within the vehicle 100 and therefore the vehicle 100 enters the sleep mode. From this point of time, power consumption is minimised for the accessory unit 160, i.e. one or more of the vehicle components included in the accessory unit 160 is switched off or put in a low power consumption mode. The battery level of the power storage unit 130 starts to decrease at a slower rate at point A, compared to the rate of decrease between t=o and point A. Between point A and point B, the battery level of the power storage unit 130 continues to decrease at the slower but relatively steady rate due to the continued power consumption of some of the vehicle components (e.g. those that remain switched on during the sleep mode) and reaches the first threshold at time point B. Immediately after point B, as the battery level of the power storage unit 130 drops below the first threshold, the control unit 120 determines that the battery level of the power storage unit 130 is lower than the first threshold and controls the transmitting unit 150 to transmit a warning notification to the user. In the present embodiment, the warning notification is a signal transmitted from the transmitting unit 150 of the vehicle 100 via the cloud network 200 to the mobile tag 300.

Between point B and point C, the battery level of the power storage unit 130 continues to decrease at a similar rate as that between point A and point B due to the continued power consumption of some of the vehicle components and reaches the second threshold at point C. Immediately after point C, as the battery level of the power storage unit 130 drops below the second threshold, the control unit 120 determines that the battery level of the power storage unit 130 is lower than the second threshold and controls the auxiliary power unit 140 to switch on. By switching on the auxiliary power unit 140 once the battery level becomes lower than the second threshold, the system 1 prevents the battery level from reaching a critical level. This critical level is lower than the second threshold. The second threshold in this embodiment is pre-selected, for example such that the battery level is prevented from reaching a critical level at which the power storage unit 130 becomes temporarily or permanently damaged.

Additionally or alternatively, the second threshold may be selected such that the battery level does not fall to a level at which there is no longer sufficient power available to drive the drivetrain (not shown in the drawing) with enough power to propel the vehicle 100.

As mentioned above, the first threshold in this embodiment is calculated based on a current power consumption rate of the vehicle 100, such that the first threshold is a battery level corresponding to a set time period before the battery level of the battery decreases to the second threshold. The set time period in the present embodiment is 15 minutes. In other words, the time period between point B and point C is 15 minutes, but is will be appreciated that other set time periods could be used.

Immediately after point C, the auxiliary power unit 140 is switched on and the battery level of the power storage unit 130 begins to increase due to the auxiliary power unit 140 charging the power storage unit 130. Between point C and point D the battery level of the power storage unit 130 increases at a relatively steady rate and reaches the first threshold at point D. As will be explained in the flowchart of Figure 4, at point D the control unit 140 may be configured to control the auxiliary power unit 140 to switch off if the vehicle is still in sleep mode.

The graph in Figure 2 is provided as an exemplary illustration of the variation in the battery level of the power storage unit 130 and it will be appreciated in alternative embodiments the increasing/ decreasing rate of the battery level may be different according to a plurality of factors relating to the power efficiency and performance of the vehicle. Also, the variation in the battery level of the power storage unit 130 may be changed depending on a continuous detection and determination of a presence of the user within the vehicle. Figure 3 is a flowchart schematically illustrating various functionalities which may be provided by the system of Figure 1, according to an exemplary embodiment. The flowchart of Figure 3 explains the operation of the system 1 during use.

The process starts at step 21. Step 21 is an ongoing step, the detection system no of the system ι is arranged to detect a presence of a user in the vehicle. In particular, in the present embodiment, the detection system no of the system ι comprises a sensor. The sensor is a mobile tag sensor located within the vehicle 100 which is configured to detect a mobile tag 300 within a predetermined range. The mobile tag 300 is comprised in a smartphone which is presumed to be carried with the user 400 when the user is away from the vehicle 100. In the present embodiment, the mobile tag sensor detects a presence of the mobile tag 300 using Bluetooth technology. Subsequently, in the next steps 22 and 23, it is determined whether a user 400 is present in the vehicle 100. In this step, the control unit 120 is arranged to determine whether the user is present within the vehicle based on detection of the detection system 110. Specifically, in the present embodiment the control unit 120 is configured such that if the mobile tag 300 is not within a two metre (2m) radius of the vehicle 100 for a predetermined time period (e.g. 10 seconds), it is determined that the user 400 is not present within the vehicle 100. Otherwise, the control unit 120 determines that the user 400 is present within the vehicle 100. It will be appreciated that the system 1 could be configured to use a distance threshold other than 2m, such lm, 5m, 10m etc. If it is determined that the user 400 is within the vehicle 100, the method may return to step 21 in which the detection system 110 continues to detect a presence of the user 400. If it is determined that the user 400 is not within the vehicle 100, the method may proceed to step 24 in which the vehicle 100 enters the sleep mode. In this step, the control unit 120 controls system 1 such that power consumption is minimised for the accessory unit 160. As mentioned above, when power consumption is minimised for the accessory unit 160, one or more of these automobile accessory components are switched off or controlled so as to be in a low power consumption mode.

If desired, the different steps discussed herein may be performed in a different order and/ or concurrently with each other. Furthermore, if desired, one or more of the above-described steps may be optional or may be combined.

Figure 4 is another flowchart schematically illustrating various functionalities which may be provided by the system of Figure 1, according to an exemplary embodiment. The flowchart of Figure 4 explains the operation of the system 1 during use. In this embodiment, entering the sleep mode of the vehicle 100 comprises effectively managing the activation of the auxiliary power unit 140.

The process starts at step 31. Steps 31 to 34 of the flowchart in Figure 4 can be considered to be similar to steps 21 to 24 of Figure 3. Hence, for the sake of brevity, the description for steps 31 to 34 will be omitted in the following discussion of Figure 3.

Subsequent to entering the sleep mode of the vehicle in step 34, it is determined in the next step 35 whether the battery level of the vehicle 100 is lower than a first threshold. As described above, battery level in the present embodiment refers to the battery level of the power storage unit 130. Also, as described above, the first threshold is calculated by the control unit 120, based on a current power consumption rate of the vehicle 100, such that the first threshold is a battery level corresponding to a set time period before the battery level of the battery decreases to a second threshold (at which the control unit 120 is configured to control switching on of the auxiliary power unit 140, as will be explained in further detail below). Specifically, the set time period in the present embodiment is 15 minutes.

If in step 35 it is determined that the battery level of the vehicle 100 is lower than the first threshold, the method may proceed to step 36 in which it is determined whether a warning notification has been transmitted from the transmitting unit 150 during a current sleep mode session. A current sleep mode session refers to a currently occurring uninterrupted sleep mode session, i.e. without exiting the sleep mode. If in step 35 it is determined that the battery level of the vehicle 100 is not lower than the first threshold, the method may proceed to step 43 in which a presence of a user is detected, similar to step 21 and step 31 of Figures 3 and 4. This allows the sleep mode to be exited if a user becomes present in the vehicle 100. By introducing a step of determining whether a warning notification has been transmitted in the current sleep mode session, unnecessary additional notification warnings can be avoided. In embodiments like the current embodiment, it may be preferred that only a single warning notification is transmitted per sleep mode session to avoid causing nuisance to the user with multiple warning notifications as the battery level fluctuates between the first threshold and the secondary threshold. If it is determined in step 36 that a notification has been transmitted during the current sleep mode session, the method may proceed directly to step 38 without performing step 37. However, if it is determined in step 36 that no notification has been

transmitted during the current sleep mode session, the method may proceed to step 37 in which a warning notification is transmitted from the transmitting unit 150. The warning notification in this embodiment is a signal transmitted from the transmitting unit 150 through the cloud network 200 to the mobile tag 300 of the user 400. Also, as described above, the mobile tag 300 in this embodiment is comprised in a smartphone at which a smartphone application is installed. The mobile tag 300 is configured to receive the warning notification via the cloud network 200 from the transmitting unit 150.

When the warning notification is received at the mobile tag 300, the mobile tag 300 is configured to present the warning notification to the user 400. In the present embodiment, the warning notification is presented to the user 400 in both audio and visual formats (e.g. a "beep" notification sound accompanied by a push notification at a screen of the smartphone). The user 400 is therefore alerted that the battery level of the vehicle 100 is lower than the first threshold and can then decide whether to return to the vehicle 100, e.g. to cause the vehicle 100 to exit the sleep mode or to switch off one or more vehicle components in order to reduce the rate of power consumption of the power storage unit 130.

In the subsequent step 38, it is determined whether the battery level of the vehicle 100 is lower than the second threshold. In this embodiment, the second threshold has a lower value than the first threshold. As described in relation to Figure 1, the second threshold in this embodiment is pre-selected such that the battery level is prevented from reaching a critical level at which the power storage unit 130 may become temporarily or permanently damaged, and/or at which the battery level is no longer sufficient to drive the drivetrain (not shown in the drawing).

If it is determined in step 38 that the battery level of the vehicle is not lower than the second threshold, the method may proceed to step 42 directly in which a presence of a user is detected, similar to step 21 and step 31 of Figures 3 and 4. This allows the sleep mode to be exited if a user becomes present in the vehicle 100. If it is determined in step 38 that the battery level of the vehicle 100 is lower than the second threshold, the method may proceed to step 39 in which the auxiliary power unit 140 is switched on under the control of the control unit 120. By switching on the auxiliary power unit 140 once the battery level becomes lower than the second threshold, the system 1 causes the battery to be charged and thereby prevents the battery level from becoming lower than a critical level (at which the power storage unit 130 would be unable to drive the electric motor of the vehicle 100).

Subsequent to switching on the auxiliary power unit 140 in step 39, the method proceeds to step 40 in which it is determined whether the battery level of the vehicle 100 is lower than the first threshold.

It is only when it is determined when the battery level of the vehicle 100 is not lower than the first threshold, the method may proceed to the next step 41 in which the auxiliary power unit 140 is switched off under the control of the control unit 120. In other words, the method remains in step 40 until the battery level becomes equal to or higher than the first threshold. This determination step in step 40 ensures that the battery level of the vehicle 100 is equal to or higher than the first threshold before switching off the auxiliary power unit 140.

Subsequent to switching off the auxiliary power unit 140 in step 41, the method proceeds to steps 42 to 44 which can be considered to be similar to steps 31 to 33 in Figure 4 and steps 21 to 23 of Figure 3. Effectively, a presence of a user is determined by the control unit 120, based on detection of the detection system 110. In step 44, it is determined by the control unit 120 whether a user is present within the vehicle 100 similar to step 33 and step 23 in Figure 4 and Figure 3.

If it is determined in step 44 that a user is present within the vehicle 100, the method may proceed to step 45 in which the control unit 120 is arranged to control the vehicle 100 to exit the sleep mode, i.e. power consumption minimisation is no longer applied to the auxiliary unit 160 such that the auxiliary unit 160 returns to an original power mode before entering the sleep mode.

If it is determined in step 44 that a user is not present within the vehicle 100, the method may return to step 35 where it is determined whether the battery level of the vehicle 100 is lower than the first threshold. Effectively, through steps 35 to 45, the battery level of the vehicle is checked to determine whether a warning notification should be transmitted and whether the auxiliary power unit should be switched on to charge the battery. At the same time, presence of a user within the vehicle is monitored so that the sleep mode can be exited appropriately when the user returns to the vehicle 100.

It should be noted that in some alternative embodiments, step 36 may not actually be performed. In these alternative embodiments, the method may proceed directly from step 35 to step 37 such that a determination of whether a warning notification has been transmitted in a current sleep mode session at step 36 is omitted.

Although it is described in an embodiment above that the user is a driver of the vehicle, in alternative embodiments, the user may not be a driver of the vehicle. For example, in the case where the vehicle is a self-driving vehicle, the user may be a passenger of the vehicle.

Although it is described in an embodiment above that the cloud network is

implemented using a cloud storage unit such as a server, in alternative embodiments the cloud network may be implemented using other types of computing resources.

Although it is described in an embodiment above that the detection system comprises a sensor which is a mobile tag sensor located within the vehicle, in alternative

embodiments the detection system may be implemented at least partly using the cloud network of the system, in addition to or as an alternative to being implemented in the vehicle. In these alternative embodiments, location information of the vehicle and location information of the user are received at the cloud network. Location of the vehicle may be transmitted from the transmitting unit of the vehicle to the cloud network. Location information of the user may be transmitted from the mobile tag in the system to the cloud network, under the presumption that the mobile tag (or a device in which the mobile tag is comprised) is always within a close vicinity of the user (e.g. in the user's pocket), and is indicative of the user's location. Based on the location information of the vehicle and the user received at the cloud network, the user's presence within the vehicle can be detected. For example, the system may be configured such that if the location of the vehicle and the location of the user are within a distance of less than 2m of each other, the user's presence within the vehicle is detected. The result of this detection may be transmitted from the cloud network to the control unit of the vehicle such that the control unit performs further determination of whether the user is within the vehicle. In alternative embodiments, the sensor may be a pressure sensor that is arranged at a driver seat of the vehicle. In these alternative embodiments, the pressure sensor is configured such that when it is determined a pressure on the driver seat is higher than a predetermined value (e.g. a pressure value equivalent to a minimum weight of an average adult person), the detection system detects a presence of the user within the vehicle. In addition, in other alternative embodiments, the sensor may be a belt buckle sensor that is configured to detect whether the belt buckle of a driver seat of the vehicle is fastened, and the detection system is arranged to detect a presence of the user within the vehicle when it is detected that the belt buckle is fastened. Although it is described in an embodiment above that the mobile tag is comprised in a smartphone, in alternative embodiments the mobile tag may be comprised in one or more other types of mobile devices. For example, the mobile tag may be comprised in a tablet, a personal digital assistant (PDA), a laptop computer, or a computer handheld device. In some other alternative embodiments, the mobile tag may be an object (e.g. a key fob) comprising a communication unit (e.g. radio frequency or near field) which allows the detection system to determine a location of the mobile tag by way of transmitting and/or receiving signals to/from the communication unit of the mobile tag. In the alternative embodiments as described in this paragraph, it is also presumed that the mobile tag is carried with the user when the user is away from the vehicle. Therefore, the location of the mobile tag is indicative of the location of the user.

In some embodiments, the mobile tag may be implemented as a software component of a mobile device. For example, the mobile tag may be comprised in a smartphone as a smartphone application. Although it is described in an embodiment above that the control unit is arranged to determine that a user is not present in the vehicle when it is detected by the detection system 110 that the mobile tag is not within the predetermined range for a

predetermined time period, in alternative embodiments the control unit may be arranged to determine the presence of a user solely based on detection results of the detection system 110, without taking into account of the time lapsed since a detection of presence or non-presence. For example, the control unit in an alternative embodiment may be arranged to immediately determine that the user is not present in the vehicle once it is determined by the mobile tag sensor that the mobile tag is out of the predetermined detecting range. In alternative embodiments, the detection system may comprise a smartphone that is equipped with other types of communication technology such as Wi-Fi, GPS, and near field communication (NFC) so as to allow a mobile tag sensor to detect a location of the mobile tag when it is within a predetermined range of the mobile tag sensor. In alternative embodiments, the power storage unit may comprise an electric capacitor unit and/or a flywheel energy storage unit, instead of a battery.

In alternative embodiments, the auxiliary power unit may be arranged to generate and provide electrical power to a motor drive unit of the vehicle, in addition to or as an alternative to generating and providing electrical power to the power storage unit.

Although it is described in an embodiment above that entering the sleep mode includes minimising power consumption of the auxiliary power unit, in alternative embodiments entering the sleep mode includes minimising power consumption of at least one of any of the vehicle components, including the accessory unit, in addition to or as an alternative to minimising power consumption of the auxiliary power unit. For example, in an alternative embodiment, when the vehicle enters the sleep mode, the control unit is configured to switch off power supply to the accessory unit, which may comprise an air conditioning unit. As another example, in an alternative embodiment, when the vehicle enters the sleep mode, the control unit is configured to reduce power consumption of at least one of the vehicle components, e.g. a stereo unit or a climate unit, for example by switching at least one of these vehicle components into a power- saving standby mode rather than a power on mode. Although it is described in an embodiment above that the first threshold is calculated by the control unit such that it is a battery level corresponding to a set time period before the battery level of the battery decreases to a second threshold, in alternative embodiment the control unit may be arranged to calculate the first threshold based on other factors that may affect the performance or power consumption efficiency of the vehicle and its components. Moreover, in some alternative embodiments, the first threshold may be a pre-selected battery level. In these alternative embodiments, the control unit is not arranged to calculate the first threshold.

In alternative embodiments, the first threshold may not be implemented in the system. In these alternative embodiments, the control unit is arranged to switch on the auxiliary power unit when the battery level of the vehicle becomes lower than the second threshold (which, in these alternative embodiments, becomes the only threshold for battery level), without transmitting a warning notification beforehand.

Although it is described in an embodiment above that the mobile tag is comprised in a smartphone and a smartphone application is installed to receive the warning notification transmitted from the transmission unit of the vehicle, in alternative embodiments, especially embodiments where the mobile tag is comprised in other types of mobile devices (e.g. a laptop computer), the mobile tag is arranged to receive and present the warning notification via other methods. For example, in an alternative embodiment the mobile tag may comprise a laptop computer and the received notification warning at the laptop computer may be presented to the user via a web application accessible via Internet.

In alternative embodiments, the mobile tag may be comprised in a key fob such that when the control unit determines that the user is not present within the vehicle, the mobile tag is further arranged to be triggered, by way of communication with the vehicle, to output a beeping sound so as to alert the user. With this arrangement, the user may have to return to the vehicle so as to switch off the power of the at least one of the vehicle components, e.g. the air conditioning unit.

In alternative embodiments, the notification warning may be presented to the user in a different format. For example, in another alternative embodiment in which the mobile tag is comprised in a smartphone, the warning notification may be presented as a vibration signal of the smartphone. As another example, in alternative embodiments the mobile tag may comprise an object (e.g. a key fob) which comprises a vibrating unit configured to provide a haptic vibrating alert when a warning notification is received from the transmission unit of the vehicle.

Although it is described in an embodiment above that the mobile tag is arranged to receive the warning notification transmitted from the transmission unit of the vehicle via the cloud network, in alternative embodiments the mobile tag may be arranged to receive the warning notification directly from the transmission unit of the vehicle without requiring the warning notification to pass through the cloud network. In these alternative embodiments, the warning notification may be transmitted using at least one of a communication technique currently known in the field, e.g. Wi-Fi, Bluetooth, etc.

In alternative embodiments, the system may not be arranged to transmit a warning notification to the mobile tag. In these alternative embodiments, the system may not comprise a transmitting unit. A warning notification may be presented via an output unit in the system in these alternative embodiments.

Although in an exemplary embodiment described above, the warning notification is presented to the user of the system, i.e. the driver of the vehicle, in alternative embodiments the warning notification may be transmitted and subsequently presented to a manager of the vehicle via the cloud network, in addition to or as an alternative to being transmitted and presented to the user (the driver).

Although in an embodiment described above, the mobile tag sensor is configured to detect a mobile tag that is within a 2m radius of the mobile tag sensor, it will be appreciated that the mobile tag sensor in alternative embodiments may be configured to detect different ranges of distances depending on the requirements of the vehicle user and/ or the vehicle manager. As described in an embodiment above, the control unit is be configured such that if the mobile tag is not within a predetermined range of distance of the vehicle for a predetermined time period, it is determined that the user is not present within the vehicle. In alternative embodiments, this predetermined time period may be chosen from a range of a few seconds (e.g. 5 seconds) to a few minutes (e.g. 5 minutes). In alternative embodiments, the second threshold may be pre-selected based on other factors that may affect the performance of the power storage unit and the auxiliary power unit. It will be appreciated that the second threshold may be pre-selected based on a number of different variables relating to the power consumption and energy efficiency of the vehicle of the system.

In alternative embodiments, the accessory unit of the system may comprise any other auxiliary vehicle component that may be switched off or switched to a power saving mode during the sleep mode without disrupting the essential operation of the vehicle.

Although it is described in an embodiment above that the detection system is part of the vehicle in the system, in alternative embodiments, the detection system may not be located or implemented in the vehicle. For example, in an alternative embodiment, the detection system may be implemented in the cloud network of the system. In addition, in alternative embodiments, other components of the vehicle may be omitted or implemented in other parts of the system instead of in the vehicle.

Embodiments of the present invention may be implemented in software, hardware, application logic or a combination of software, hardware and application logic. The software, application logic and/or hardware may reside on memory, or any computer media. In an example embodiment, the application logic, software or an instruction set is maintained on any one of various conventional computer-readable media. In the context of this document, a "memory" or "computer-readable medium" maybe any media or means that can contain, store, communicate, propagate or transport the instructions for use by or in connection with an instruction execution system, apparatus, or device, such as a computer.

Although various aspects of the present disclosure are set out in the independent claims, other aspects of the present disclosure comprise other combinations of features from the described embodiments and/ or the dependent claims with the features of the independent claims, and not solely the combinations explicitly set out in the claims.

It is also noted herein that while the above describes various examples, these descriptions should not be viewed in a limiting sense. Rather, there are several variations and modifications which may be made without departing from the scope of the present invention as defined in the appended claims. For instance, although the above examples have been described with reference to detection technology using Bluetooth, it will be appreciated that the principles described herein are equally applicable to any presence detection technology.

Claims

1. A method for controlling a power-saving mode of a vehicle, the method comprising:

detecting a presence of a user;

determining whether the user is present within the vehicle based on the detection, and

controlling the vehicle to enter the power-saving mode if it is determined that the user is not present within the vehicle,

wherein entering the power-saving mode includes minimising power consumption of at least one auxiliary power unit arranged to generate electricity for charging a power storage unit of the vehicle.

2. The method of claim l, wherein the auxiliary power unit comprises a range extender.

3. The method of claim 2, wherein the range extender comprises an internal combustion engine.

4. The method of any preceding claim, wherein the power storage unit comprises at least one battery.

5. The method of claim 4, further comprising comparing a battery level of the vehicle with a first threshold during the power-saving mode; and

transmitting a warning notification when the battery level is lower than the first threshold.

6. The method of claim 5, wherein the warning notification is transmitted through a cloud storage system to at least one of: a mobile device of the user and a manger of the vehicle.

7. The method of claim 5 or claim 6, further comprising comparing the battery level of the vehicle with a second threshold during the power-saving mode; and

switching on the auxiliary power unit when the battery level is lower than the second threshold.

8. The method of any of the preceding claims, wherein detecting the presence of a user comprises:

receiving location information of the vehicle and location information of the user; and

detecting a presence of the user within the vehicle when it is determined that the vehicle and user are within a predetermined distance of each other.

9. The method of claim 8, wherein the location information of the user is received from a mobile tag.

10. The method of any preceding claim, wherein detecting the presence of a user comprises:

detecting a pressure on a driver seat of the vehicle; and

detecting a presence of the user within the vehicle when the pressure on the driver seat exceeds a predetermined value.

11. The method of any of the preceding claims, wherein it is determined that the user is not within the vehicle only when the presence of the user is not detected for a predetermined time period.

12. Apparatus comprising means for performing a method according to any preceding claim.

13. Computer-readable instructions which, when executed by computing apparatus, cause the computer apparatus to perform a method according to any of claims 1 to 11.

14. A system for controlling a power-saving mode for a vehicle, the system comprising:

a detector arranged to detect a presence of a user within the vehicle;

a controller arranged to determine whether the user is present within the vehicle based on detection of the sensor, and to control the vehicle to enter the power- saving mode if it is determined that the user is not present within the vehicle;

15. The system of claim 14, further comprising the power storage unit and the auxiliary power unit arranged to generate electricity for charging the power storage unit.

16. The system of claim 13 or claim 14, wherein entering the power-saving mode further comprises minimising power consumption of at least one vehicle component comprising at least one of: an air conditioning unit, a stereo unit, a climate control unit, a GPS unit, a display unit, and/or a lighting unit.