TECHNICAL FIELD

The present disclosure relates to controlling movement of a vehicle. In particular, but not exclusively, it relates to controlling movement of a road vehicle such as a car in a remote control mode of operation.

Aspects of the invention relate to apparatus for controlling movement of a vehicle, a system for controlling movement of a vehicle, a vehicle, a method of controlling movement of a vehicle, and a computer program.

BACKGROUND

Suitably equipped vehicles can be operated in a remote control drive mode via a remote device, such as a smart phone having a suitable remote control drive program, to provide convenient means for an operator of the vehicle to control movement the vehicle from a position outside of the vehicle. This may, for example, be to allow the operator to get a more immediate and encompassing view of the terrain, to allow the operator to carry out a task outside the vehicle, such as opening and subsequently closing a gate across the vehicle's path and manoeuvring the vehicle through the gate, or to park the vehicle—particularly in a restricted space.

One problem with such an arrangement is how to maximize the safety of the vehicle and people within the vicinity of the vehicle, including the vehicle operator, while the vehicle is being remotely controlled.

It is an aim of the present invention to address this problem.

SUMMARY OF THE INVENTION

Aspects and embodiments of the invention provide apparatus for controlling movement of a vehicle, a system for controlling movement of a vehicle, a vehicle, a method of controlling movement of a vehicle, and a computer program as claimed in the appended claims.

According to an aspect, there is provided apparatus for controlling movement of a vehicle, the apparatus comprising processing means configured to: receive first signals from a receiving means in dependence on received transmitted signals from a remote control device indicating a requested motion of a vehicle; receive second signals indicative of a value of traction of the vehicle; determine a maximum speed value for the vehicle in dependence on the value of traction of the vehicle; and provide an output signal for controlling speed of the vehicle based on the requested motion, wherein the output signal is limited dependent upon the maximum speed value. The value of traction of the vehicle is classified into discrete levels, and the maximum speed value is set at corresponding discrete levels in dependence on the level to which the value of traction is classified.

In this manner, the maximum speed at which the vehicle can be operated in the remote control drive mode can be limited in dependence on the traction available to the vehicle, thereby ensuring that the vehicle can be stopped within a certain distance or time. Thus, the operator of the remote control can be confident that the vehicle will not be permitted to inadvertently travel at a speed that could compromise the safety of the vehicle and people within the vicinity of the vehicle, including the operator.

In certain embodiments, the classification of the value of traction into discrete levels comprises the processing means being configured to: compare the value of traction of the vehicle to a first threshold value (T1) and a second threshold value (T2). If the value of traction of the vehicle is above the second threshold value (T2), then the value of traction is classified as ‘high’ and a relatively high maximum speed value level (S2) is set. If, however, the value of traction of the vehicle is above the first threshold value (T1) and below the second threshold value (T2), then the value of traction is classified as ‘medium’ and a relatively low maximum speed value level (S1) is set. If the value of traction of the vehicle is below the first threshold value (T1), then the value of traction is classified as ‘low’ and a maximum speed value level (S0) of zero is set. Hence, the maximum available speed for the vehicle in remote control drive mode can be restricted in a simple manner according to which of three levels of traction the current conditions meet. So, for particularly slippery conditions, such as for a value of traction corresponding to a ‘low’ coefficient of friction in the range of 0.1 to 0.40, the vehicle may be prevented from operating in a remote control drive mode—i.e. the vehicle speed may be restricted to a maximum speed of 0 kph. For conditions in which a high level of grip is available, such as for a value of traction corresponding to a ‘high’ coefficient of friction in the range of 0.61 to 1.0, the vehicle may be operated up to the full available speed in a remote control drive mode—typically 6 kph. For conditions between these extremes, where only a mid-level of grip is available, here being a value of traction corresponding to a ‘medium’ coefficient of friction in the range of 0.41 to 0.60, the vehicle speed may be restricted accordingly. By way of example, the maximum speed at which the vehicle may be operated may be limited to 3 kph. As such, if the operator attempts to request faster movement, that will be prevented. In certain embodiments, the low, medium and high coefficient of friction classifications may correspond to corresponding low, medium and high maximum speeds permissible in remote control drive mode; i.e. rather than preventing movements in low friction conditions, permitting movements of up to say 2 kph, with speeds up to 4 kph permitted when there is a medium friction classification, and up to 6 kph allowed in high friction conditions, as with the above example. In other embodiments, the level of traction may be divided into more or less than three classifications, with a corresponding number of threshold values.

The processing means may be configured to determine the value of traction from the second signals. In this embodiment, the determination of the value of traction is carried out at the processing means rather than receiving a pre-determined value of traction from another element.

The processing means may be configured to receive the second signals from at least one vehicle sensor. The vehicle sensor may provide data indicative of at least one of: wheel speeds; wheel loads; suspension heights; vehicle orientation; roll angle; pitch angle; vehicle ground speed; vehicle acceleration and deceleration; and steering rack force. In other words, the processing means can receive raw data from the vehicle sensors and determine from that data a value of traction of the vehicle.

In addition to or instead of receiving the second signals from one or more vehicle sensors, the processing means may be configured to receive the second signals from at least one vehicle controller. In this case, the at least one vehicle controller may provide data indicative of at least one of: a coefficient of friction of the tyres with the surface with which they are in contact; ABS intervention; and traction control intervention. Thus, the determination of the value of traction may be carried out in a separate element to the processing means and be communicated to the processing means in that form, ready for use in limiting the speed at which the vehicle can be operated, or the processing means may take that input and combine it with other data to determine the value of traction more holistically.

According to one aspect, there is provided a controller for determining a value of traction of the vehicle, the controller comprising processing means configured to: receive steering force signals indicative of a steering rack force; receive normal force signals indicative of a normal force at steerable wheels of the vehicle; determine a coefficient of friction between the steerable wheels and the ground in dependence on the steering force signals and the normal force signals; and provide an output signal dependent upon the coefficient of friction indicative of the value of traction of the vehicle. The coefficient of friction for the steerable tyres (either singly or as a set) may thus be inferred from the normal force at the steerable wheels and the steering rack force at any given time. From that, the overall value of traction for the vehicle can be determined. The output signal from the controller for determining a value of traction of the vehicle may correspond to the second signals indicative of a value of traction of the vehicle described above.

As well as limiting the maximum permissible speed according to the traction available, other requests from the remote control device may likewise be limited according to the available traction. By way of example, a request for acceleration may be limited according to the conditions, with an acceleration profile being a function of the traction available: e.g. a relatively steep acceleration profile being followed under high traction conditions, down to a shallow acceleration profile being followed under low traction conditions. Optionally, discrete acceleration profiles may be provided corresponding to the discrete classifications for the value of traction of the vehicle.

The processing means may be configured to determine, from the first signals or additional proximity signals received from a proximity sensing means, a distance value indicative of a distance from a point on the vehicle to an obstacle, in which case the maximum speed value for the vehicle is determined in dependence on the value of traction of the vehicle and on the distance value. Hence, the proximity of nearby obstacles may be taken as an additional factor for determining the maximum speed at which the vehicle should be allowed to travel, to ensure that the vehicle will be able to stop in advance of a collision with such an obstacle. The proximity sensing means may also be capable of determining a relative closing speed of the vehicle and the obstacle. In this way, movement of obstacles, such as people, animals or other vehicles, may be accounted for in the calculations and the determination of an appropriate maximum speed for the conditions which will ensure that the vehicle can be stopped in advance of a collision.

The processing means may be configured to determine, from additional angle signals received from an angle sensing means, one or both of a roll angle and a pitch angle of the vehicle, in which case the maximum speed value for the vehicle is determined in dependence on the value of traction of the vehicle and on one or both of the roll angle and the pitch angle. Accordingly, the contours of the terrain may be taken into account too, to ensure that the vehicle is kept under control. For example, the maximum allowable vehicle speed may be adjusted, in conjunction with the level of traction available and, optionally, with the proximity of obstacles, inversely proportional to the steepness of the gradient. In other words, if a remote operator requests a maximum 6 kph speed to climb or descend, then the processing means will adjust the actual vehicle speed by taking the pitch angle as well as the level of friction into account. The roll angle may be taken into account also or instead of the pitch angle, to prevent the remote operator from putting the vehicle into a possible roll situation, which may be difficult for the remote operator to perceive from outside the vehicle. The angles at which the vehicle may be permitted to be operated in a remote control mode of operation may be affected by the traction available to the vehicle wheels, so by taking the combination of both traction and angles into account, the vehicle can be kept under safe operating conditions.

The processing means may be configured to provide an output signal to cause the parking brake of the vehicle to be applied and the vehicle transmission to be put into park mode in dependence on the maximum speed value being determined to be zero. Thus, the vehicle can be placed in a safe, secure state if it has been necessary to bring the vehicle to a stop due.

This on its own may be considered as an invention in its own right, so according to another aspect, there is provided apparatus for controlling movement of a vehicle, the apparatus comprising processing means configured to: receive first signals from a receiving means in dependence on received transmitted signals from a remote control device indicating a requested motion of a vehicle; receive angle signals, from an angle sensing means, indicative of one or both of a roll angle and a pitch angle of the vehicle; determine a maximum speed value for the vehicle in dependence on one or both of the roll angle and the pitch angle; and provide an output signal for controlling speed of the vehicle based on the requested motion, wherein the output signal is limited dependent upon the maximum speed value. The processing means is configured to provide an output signal to cause the parking brake of the vehicle to be applied and the vehicle transmission to be put into park mode in dependence on the maximum speed value being determined to be zero.

According to this aspect, the maximum speed at which the vehicle can be operated in the remote control drive mode can be limited purely in dependence on the contours of the terrain, not necessarily also taking traction available to the vehicle into account, thereby ensuring that the vehicle can be stopped safely within a certain distance or time. Thus, the operator of the remote control can be confident that the vehicle will not be permitted to inadvertently travel at a speed that could compromise the safety of the vehicle and people within the vicinity of the vehicle, including the operator. Additionally, because the processing means is configured to provide an output signal to cause the parking brake of the vehicle to be applied and the vehicle transmission to be put into park mode in dependence on the maximum speed value being determined to be zero, the vehicle can be placed in a safe, secure state if it has been necessary to bring the vehicle to a stop.

The angle signals may be indicative both of absolute values of one or both of the roll angle and the pitch angle, and rates of change thereof. A more accurate determination of safe operating conditions and, therefore, safe operating speeds can be made by taking into account not only the current absolute values of the pitch and/or roll angles, but also how quickly they are changing.

The angle sensing means may comprise at least one sensor selected from the group comprising: a roll angle sensor; a pitch angle sensor; a vehicle inertial measurement unit (IMU); and suspension height sensors. Hence, the pitch and roll angles, as well as their rates of change, may be measured directly or indirectly.

In certain scenarios, the processing means may be configured to provide an output signal to prevent operation of the vehicle in a remote control driving mode, thereby only permitting the vehicle to be driven in manual mode until conditions change so that the maximum speed value is determined to be greater than zero. Thus, the vehicle can be held in a safe, secure state if it has been necessary to bring the vehicle to a stop. In certain scenarios, the user may be prevented from operating the vehicle in a remote control mode until the conditions have changed—for example by having moved the vehicle (in manual mode) to a different terrain where the traction is higher and/or the contours are less steep—and operation of the vehicle in remote control drive mode can be resumed safely. The same principle can be applied to situations where the vehicle has been prevented from setting off from rest in a remote control drive mode.

The processing means may comprise an electronic processor electrically coupled to an electronic memory device having instructions stored therein and the electronic processor may have an electrical input for receiving the first signals and the second signals.

According to another aspect of the invention, there is provided a system for controlling the movement of a vehicle comprising the apparatus according to any of the above described aspects, and a receiving means for receiving the transmitted signals from a remote control device via a wireless local area network.

According to yet another aspect, there is provided a vehicle comprising an apparatus or a system according to any of the above-described aspects wherein the speed of the vehicle is limited to a speed dependent on the maximum speed value.

According to an aspect of the invention, there is provided an apparatus as described above, wherein said processing means configured to: receive said first signals; receive said second signals; determine a maximum speed value for the vehicle; and provide an output signal for controlling speed of the vehicle, comprises: an electronic processor having an electrical input for receiving said first and second signals; and an electronic memory device electrically coupled to the electronic processor and having instructions stored therein; wherein the processor is configured to access the memory device and execute the instructions stored therein such that it is operable to determine a maximum speed value for the vehicle in dependence on the value of traction of the vehicle, and to provide an output signal for controlling speed of the vehicle based on the requested motion, wherein the output signal is limited dependent upon the maximum speed value.

According to another aspect, there is provided an apparatus as described above, wherein said processing means configured to: receive said first signals; receive said angle signals; determine a maximum speed value for the vehicle; and provide an output signal for controlling speed of the vehicle, comprises: an electronic processor having an electrical input for receiving said first signals and said angle signals; and an electronic memory device electrically coupled to the electronic processor and having instructions stored therein; wherein the processor is configured to access the memory device and execute the instructions stored therein such that it is operable to determine a maximum speed value for the vehicle in dependence on one or both of a roll angle and a pitch angle of the vehicle, and to provide an output signal for controlling speed of the vehicle based on the requested motion, wherein the output signal is limited dependent upon the maximum speed value.

There is further disclosed an apparatus for controlling movement of a vehicle, the apparatus comprising processing means configured to: receive first signals from a receiving means in dependence on received transmitted signals from a remote control device indicating a requested motion of a vehicle; receive one or more second signals indicative of a trailer being connected to the vehicle; and provide an output signal for controlling movement of the vehicle based on the requested motion, wherein the output signal is limited dependent on the one or more second signals.

When a trailer is attached to a vehicle, it may obscure certain of the vehicle's sensors—such as one or more of the parking sensors, radars, or cameras. Signals from those sensors may be useful in maintaining full control of the vehicle during a remote control mode of operation—for example as proximity sensors to prevent collisions with obstacles in the vicinity of the vehicle; signals from those proximity sensors being taken as inputs to a collision prevention system that will automatically bring the vehicle to a controlled stop if an obstacle is detected as being too close to the path of the vehicle. This is particularly significant in the case of reverse movements. Hence, if at least some of those sensors are not capable of operating at their full capabilities then the collision prevention system may not be relied upon to avoid such collisions. Moreover, a connected trailer would typically result in increased stopping distances for the vehicle. Thus, with a trailer attached, there is an increased chance of colliding with an obstacle when operating the vehicle in a remote control mode. Accordingly, by detecting the presence of a trailer connected to the vehicle, the remote control mode of operation may be limited (e.g. restricted) so as to reduce the risk of collision.

The output signal may be inhibited in dependence on the one or more second signals. Thus, in certain embodiments, operation in the remote control mode is fully prevented and the vehicle may only be moved by driving it in manual mode.

The output signal may be for limiting the speed of the vehicle to a maximum speed value. By limiting the maximum speed of the vehicle whilst in remote control mode with a trailer connected, the vehicle will have a reduced required braking distance, and will allow the operator a greater time to react to any potential collisions. Another way to limit the remote control mode of operation would be to prevent movements in reverse, since that is the direction in which the trailer may be obscuring the field of view of the relevant sensors.

The maximum speed value may be zero. This corresponds, in effect, to the limitation being a full prevention of operation in the remote control mode. The output signal may be for applying a braking force to the vehicle. Thus, if a trailer is detected as being connected, the vehicle brakes may be applied either to prevent move-off of the vehicle, or to bring the vehicle to a controlled stop if the presence of the trailer is only detected after the vehicle has begun to be moved under remote control operation.

Receiving the one or more second signals may comprise receiving a trailer connection signal from a trailer connection sensor. Receiving the trailer connection signal may comprise receiving a signal on the vehicle CAN bus indicative of an electrical connection between the trailer and the vehicle.

The trailer connection sensor may comprise one or more proximity sensors and receiving the trailer connection signal may comprise receiving a signal output in dependence on the one or more proximity sensors detecting the presence of an object at a set distance from the vehicle. For a given trailer and connection mechanism, the distance from the rear of the vehicle (the proximity sensor(s) at the rear of the vehicle) to the front of the trailer will be known. As such, if the proximity sensors detect an object at that known distance then it can be inferred that the given trailer is connected to the vehicle. The one or more proximity sensors may be selected from the group comprising: ultrasound sensors, radar sensors and optical sensors. It will be understood that any sensor or group of sensors that can be used to detect whether an object is at a particular distance from the vehicle may be employed. The set distance may be constant during movement of the vehicle. With a known trailer and a known connection mechanism, the connection of the trailer can be inferred when the vehicle is stationary. However, there is a risk of a false positive, in that there may just be another object such as an unconnected trailer or a wall, at that location. It would be inconvenient if an operator could not use the remote control mode to move the vehicle away from that obstacle simply because it was at a distance where it could have been taken to be a connected trailer. Thus, to avoid such false positives, in certain embodiments that movement is allowed under remote control operation—possibly in a limited capacity, such as away from the obstacle only, and/or at a slow speed—yet the signals from the proximity sensors continue to be monitored during that initial movement and if the distance to the object remains substantially constant, then it can be inferred that it is in fact connected to the vehicle (i.e. a trailer). Once it is determined that a trailer is connected, then operation in the remote control mode will typically be ended by bringing the vehicle to a controlled stop (i.e. by application of the vehicle brakes) and preventing any further remote control of the vehicle until the trailer has been disconnected. With this means of detecting the presence of an object connected to the rear of the vehicle, the remote control mode can be limited or inhibited even when the object is not a trailer per se; by way of example, another vehicle connected via a tow-rope.

According to another aspect of the invention, there is provided a method of controlling movement of a vehicle, the method comprising: receiving first signals from a receiving means in dependence on received transmitted signals from a remote control device indicating a requested motion of a vehicle; receiving second signals indicative of a value of traction of the vehicle; determining a maximum speed value for the vehicle in dependence on the value of traction of the vehicle; and providing an output signal for controlling speed of the vehicle based on the requested motion, wherein the output signal is limited dependent upon the maximum speed value. The value of traction of the vehicle is classified into discrete levels, and the maximum speed value is set at corresponding discrete levels in dependence on the level to which the value of traction is classified

Determining a maximum speed value may comprise determining the value of traction from the second signals received from at least one vehicle sensor.

Determining the value of traction may comprise receiving steering force signals indicative of a steering rack force; receiving normal force signals indicative of a normal force at steerable wheels of the vehicle; determining a coefficient of friction between the steerable wheels and the ground in dependence on the steering force signals and the normal force signals; and providing an output signal dependent upon the coefficient of friction indicative of the value of traction of the vehicle.

The method may comprise determining, from the first signals or an additional proximity signal received from a proximity sensing means, a distance value indicative of a distance from a point on the vehicle to an obstacle; wherein determining the maximum speed value for the vehicle is in dependence on the value of traction of the vehicle and on the distance value.

The method may comprise determining, from additional angle signals received from an angle sensing means, one or both of a roll angle and a pitch angle of the vehicle; wherein determining the maximum speed value for the vehicle is in dependence on the value of traction of the vehicle and on one or both of the roll angle and the pitch angle.

According to another aspect of the invention, there is provided a method of controlling movement of a vehicle, the method comprising: receiving first signals from a receiving means in dependence on received transmitted signals from a remote control device indicating a requested motion of a vehicle; receiving angle signals, from an angle sensing means, indicative of one or both of a roll angle and a pitch angle of the vehicle; determining a maximum speed value for the vehicle in dependence on one or both of the roll angle and the pitch angle; providing an output signal for controlling speed of the vehicle based on the requested motion, wherein the output signal is limited dependent upon the maximum speed value; and providing an output signal to cause the parking brake of the vehicle to be applied and the vehicle transmission to be put into park mode in dependence on the maximum speed value being determined to be zero.

The angle signals may be indicative both of absolute values of one or both of the roll angle and the pitch angle, and rates of change thereof.

Providing an output signal may comprise providing an output signal to at least one of a brake controller and a powertrain controller, to cause the speed of the vehicle to be limited to a speed corresponding to the maximum speed value.

There is further disclosed a method of controlling movement of a vehicle, the method comprising: receiving first signals from a receiving means in dependence on received transmitted signals from a remote control device indicating a requested motion of a vehicle; receiving one or more second signals indicative of a trailer being connected to the vehicle; and providing an output signal for controlling movement of the vehicle based on the requested motion, wherein the output signal is limited dependent on the one or more second signals.

Providing an output signal may comprise providing an output signal to at least one of: a powertrain controller, a transmission controller, a brake controller, and a steering controller to cause the vehicle to move in accordance with the requested motion. The output signal may be for limiting the speed of the vehicle to a maximum speed value. The maximum speed value may be zero.

According to even yet another aspect, there is provided a computer program which, when executed by a processor, is arranged to perform a method as described above. Optionally, the computer program is stored on a computer-readable medium.

Within the scope of this application it is expressly intended that the various aspects, 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 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.

