An apparatus for controlling a tracked vehicle

Abstract

A controller (118) comprising means for obtaining (142, 144, 146, 148) a measured displacement data of at least one pedal among two pedal sets (110, 112) of the tracked vehicle and controlling a speed of each of the tracks of the tracked vehicle based on a relative displacement of a pedal of the first pedal set (110) and a pedal of the second pedal set (112).

Description

[0001] AN APPARATUS FOR CONTROLLING A TRACKED VEHICLE

[0002] TECHNICAL FIELD OF THE INVENTION

[0003] The invention relates to a method and arrangement for controlling a tracked vehicle.

[0004] BACKGROUND OF THE INVENTION

[0005] It is known from prior art that tracked vehicles such as civil engineering machines utilises tracks for moving the vehicle. The tracks may be controlled by the operator of the machine e.g. by using pedals. Each of the tracks is often associated with a pedal with two functionalities, said pedal controlling the track in both directions based on which functionality is used.

[0006] SUMMARY OF THE INVENTION

[0007] According to a first aspect there is provided a method for moving a tracked vehicle comprising: obtaining at a controller a measured displacement data of at least one pedal among two pedal sets of the tracked vehicle, and controlling a speed of each of the tracks of the tracked vehicle based on a relative displacement of a pedal of the first pedal set and a pedal of the second pedal set.

[0008] The method may further comprise: performing, at the controller, at least one of the following: determining, based on the measured displacement of a pedal of the first pedal set, a control signal causing a first track of the tracked vehicle and a second track of the tracked vehicle to rotate in a common direction at a same speed, or determining, based on the measured displacement of a pedal of the second pedal set, a control signal causing the first track and the second track to rotate in opposite directions at a same speed, or determining, based on the measured displacement of a pedal of the first pedal set and the measured displacement of a pedal of the second pedal, a control signal causing the first track and the second track to rotate in a common direction at different speeds; providing, at the controller, the determined control signal to one or more actuators of the first track and the second track of the tracked vehicle.

[0009] The control signal of the method may be configured to cause one of the tracks to stop when the obtained measured displacement data comprises a measured displacement of a pedal of the first pedal set, a measured displacement of a pedal of the second pedal set and the measured displacement indicates an extreme position for the pedal of the second pedal set.

[0010] According to a second aspect there is provided a controller comprising: means for obtaining a measured displacement data of at least one pedal among two pedal sets of the tracked vehicle, controlling a speed of each of the tracks of the tracked vehicle based on a relative displacement of a pedal of the first pedal set and a pedal of the second pedal set.

[0011] The controller may further comprise means for determining a control signal based on the obtained measured displacement data, and means for performing at least one of the following: determining, based on the measured displacement of a pedal of the first pedal set, a control signal causing a first track of the tracked vehicle and a second track of the tracked vehicle to rotate in a common direction at a same speed, or determining, based on the measured displacement of a pedal of the second pedal set, a control signal causing the first track and the second track to rotate in opposite directions at a same speed, or determining, based on the measured displacement of a pedal of the first pedal set and the measured displacement of a pedal of the second pedal, a control signal causing the first track and the second track to rotate in a common direction at different speeds; means for providing the determined control signal to one or more actuators of the first track and the second track of the tracked vehicle.

[0012] Each pedal of the first pedal set and each pedal of the second pedal set associated with the controller may have two functionalities for controlling a movement of the tracked vehicle and the controller is caused to perform at least one of the following: determine which of a first functionality and a second functionality of the two functionalities for a first pedal of the first pedal set is applied for controlling the movement of the tracked vehicle based on a displacement of at least one pedal of the second pedal set; or determine which of a first functionality and a second functionality of the two functionalities for a second pedal of the first pedal set is applied for controlling the movement of the tracked vehicle based on a displacement of at least one pedal of the second pedal set; or determine which of a first functionality and a second functionality of the two functionalities for a first pedal of the second pedal set is applied for controlling the movement of the tracked vehicle based on a displacement of at least one pedal of the first pedal set; or determine which of a first functionality and a second functionality of the two functionalities for a second pedal of the second pedal set is applied for controlling the movement of the tracked vehicle based on a displacement of at least one pedal of the first pedal set.

[0013] The first pedal of the first pedal set associated with the controller may be determined to have a first functionality of the two functionalities, based on determining that the first pedal of the first pedal set is displaced without another pedal of the second pedal unit is displaced at the same time, and the first pedal of the first pedal set is determined to have a second functionality of the two functionalities, based on determining that the first pedal of the first pedal set is displaced and another pedal of the second pedal unit is displaced at the same time; or the second pedal of the first pedal set is determined to have a first functionality of the two functionalities, based on determining that the second pedal of the first pedal set is displaced without another pedal of the second pedal unit is displaced at the same time, and the second pedal of the first pedal set is determined to have a second functionality of the two functionalities, based on determining that the second pedal of the first pedal set is displaced and another pedal of the second pedal unit is displaced at the same time.

[0014] BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Next the invention will be described in greater detail with reference to exemplary embodiments in accordance with the accompanying drawings, in which:

[0016] Figure 1 illustrates an example of a controller according to the invention.

[0017] Figure 2 illustrates an example of a method according to the invention.

[0018] Figure 3 illustrates an example of the tracks of a tracked vehicle according to the invention.

[0019] Figure 4 illustrates an example of the tracks of a tracked vehicle according to the invention.

[0020] Figure 5 illustrates a flowchart of a method for moving a tracked machine according to an example embodiment of the invention. DETAILED DESCRIPTION

[0021] Tracked vehicles such as civil engineering machines are typically working on a certain location at a construction site and moving of the machine is practically minimal. However, tracks are needed for moving the tracked vehicle for short distances between working locations on the construction site. The tracked vehicle is often transported to the construction site using a lorry or another means of transport and therefore the longest distances for the tracked vehicle to move is the last mile from the lorry to the construction site.

[0022] The tracks of a tracked vehicle are usually controlled by driver’s feet using pedals which are placed on the floor of the driver’s cabin. Usually there are two pedals each control rolling of a track in two directions, forwards and backwards, depending on the tilt direction of the pressed pedal.

[0023] However, there are problems with the above-mentioned existing solution. While a machine is moved on the construction site, it is often moved in a straight line from the location of the previous task to e.g. pick up materials and then returned to the location for the execution work to start. Thus, an additional problem with the existing solution is that with two separate pedals it is challenging to control the two pedals evenly to ensure a straight movement. This is because both pedals are controlled by one foot and both pedals must be pressed so that their displacements are equal in order for the machine to move straight. Following from the differing distance of the displacement of the pedals, the tracks are moved at different speeds compared with each other causing the vehicle to turn.

[0024] An object of the invention is to alleviate and eliminate the problems relating to the known prior art. Especially the object of the invention is to provide an apparatus for an advanced version of controlling and / or moving a tracked machine.

[0025] The object of the invention can be achieved by the features of independent claims. The invention is explained in detail below.

[0026] A tracked vehicle may be a civil engineering machine such as an excavator, a piling rig, a drilling rig or any other vehicle configured to perform civil engineering machine tasks and is equipped with tracks to move the vehicle on a construction site. Tracked vehicles are commonly used on e.g. construction sites and other areas with a challenging surface and terrain as they provide a better stability and traction compared with vehicles equipped with wheels. A tracked vehicle usually comprises at least two tracks located parallel to each other within a certain distance apart in a direction of width of the vehicle. The tracks may be arranged on track wheels. When the tracked vehicle is supported on the ground by the tracks, the tracks may be moved by the track wheels for causing a movement of the tracked vehicle on the ground. Accordingly, a movement of the tracks to one direction causes the movement of the vehicle to a one direction of the vehicle, and a movement of the tracks to another direction causes the movement of the vehicle to another direction of the vehicle. On the other hand, if there is at least one track that is moved to a different direction than one or more further tracks of the tracked vehicle, a rotating movement at a position on the ground may be caused or at least curved path of movement of the tracked vehicle into a direction may be caused. In the latter case, the tracked vehicle is caused to turn and at the same time advance either forwards or backwards. Tracks can be made from various materials such as steel plates, rubber, or a combination thereof.

[0027] The direction of the tracks which they are intended to move defines a heading of the tracked vehicle. A tracked vehicle moving in a straight line according to its heading, thus a movement of the tracked vehicle straight ahead or straight backward, may be achieved in a situation when both tracks are on the ground and moving in the same direction at a common speed. The heading of the tracked vehicle may be changed by controlling the tracks to move in opposite directions with respect to each other, whereby the tracked vehicle may be turned in place, or by controlling the tracks to move at different speeds in the same direction, whereby the tracked vehicle is caused to turn and at the same time advance either forwards or backwards. Additionally, the heading of the tracked vehicle may be changed when the tracks are configured to move with different speeds.

[0028] In Fig. 1 there is provided an exemplary controlling system 100 configured to control the movement of a tracked vehicle. The system comprises a pedal unit 114 and a controller 118. The pedal unit is electrically coupled to the controller. The pedal unit comprises two pedal sets 110, 112 each pedal set comprising two pedals 102, 104, 106, 108. It should be noted that in some cases there may be additional pedal sets and / or pedals. Each pedal is associated with a sensor 142, 144, 146, 148, which is configured to measure, i.e. to determine, a displacement of the pedal with which it is associated with and to transmit the determined displacement data to the controller 118. The controller 118 is electrically coupled to at least two valves 124, 126. Each valve 124, 126 is configured to control a hydraulic fluid flow for controlling a track 138, 140 of the tracked vehicle. In an example, each of the valves 124, 126 may be hydraulically coupled to hydraulic motors that are coupled to drive one or more track wheels of the tracks 138, 140 and to a hydraulic pump 130 for supplying hydraulic pressure to the valves. The hydraulic pump 130 is powered by the motor 150 of the tracked vehicle. The controller 118 is further electrically coupled to the hydraulic pump and the motor for controlling the operation of the hydraulic pump and the motor.

[0029] In Fig. 2 and Fig. 3 there is provided examples of a tracked vehicle 300. In Fig. 2 the tracked vehicle is viewed from a direction of a heading, i.e. back / front, of the of the tracked vehicle. The tracked vehicle comprises a first track 302 and a second track 304. The first and the second tracks 302, 304 are separated by a centre part 306, e.g. a frame of the tracked vehicle, that serves for a support structure of the tracked vehicle In Figure 3 there is a side view of the track 302, 304 of the tracked vehicle. The tracks 302, 304 are arranged on track wheels 308 supported to a track frame 310. In this way the tracked vehicle may be moved by rotating the track wheels 308 that move the tracks 302, 304. Seen from the side as in the Fig. 3, the tracks 302, 304 may be rotated around the track wheels 308 clockwise or anticlockwise.

[0030] According to a first aspect there is provided a method for moving a tracked vehicle comprising: obtaining at a controller a measured displacement data of at least one pedal among two pedal sets of the tracked vehicle and controlling a speed of each of the tracks of the tracked vehicle based on a relative displacement of a pedal of the first pedal set and a pedal of the second pedal set.

[0031] The two pedal sets may be a first pedal set, and a second pedal set each comprising two pedals. Displacing a pedal at a pedal set causes a controller to control the tracks of the tracked vehicle. The relative displacement of the pedal indicates how fast the tracks of the tracked vehicle should move. The controller may determine a plurality of different functionalities for the pedals depending on which pedal is displaced, in which of the pedal sets the displaced pedal is located at and if more than one of the pedals are displaced simultaneously among the pedals of the pedal sets.

[0032] According to the first aspect the method may further comprise: determining a control signal based on the obtained measured displacement data.

[0033] For controlling the tracked vehicle, the controller may determine a control signal which is based on the measured displacement data. The control signal may e.g. provide the actuators of the civil engineering machine relevant information, how the actuators should operate in order to execute the correct movement corresponding to the pedal displacement / displacements of the pedal sets.

[0034] According to the first aspect the method may further comprise: performing, at the controller, at least one of the following: determining, based on the measured displacement of a pedal of the first pedal set, a control signal causing a first track of the tracked vehicle and a second track of the tracked vehicle to rotate in a common direction at a same speed, or determine, based on the measured displacement of a pedal of the second pedal set, a control signal causing the first track and the second track to rotate in opposite directions at a same speed, or determine, based on the measured displacement of a pedal of the first pedal set and the measured displacement of a pedal of the second pedal, a control signal causing the first track and the second track to rotate in a common direction at different speeds; providing, at the controller, the determined control signal to one or more actuators of the first track and the second track of the tracked vehicle.

[0035] Said pedal sets comprising a first pedal set for causing tracks of the tracked vehicle to rotate in opposite directions and a second pedal set for causing tracks of the tracked vehicle to rotate in a common direction at a same speed. The controller is configured to obtain measured displacement data. The measured displacement data may be obtained from at least one pedal unit and / or at least one sensor associated with a pedal. In a case the data is obtained from a pedal unit, it has received it from at least one sensor associated with a pedal. The measured displacement data is determined based on a displacement caused by an operator of the tracked vehicle pressing the pedal or pedals to control the movement of the vehicle. The measured displacement data may indicate how the vehicle, more specifically the tracks of the vehicle, should move depending on which pedal, or pedals are pressed by the operator. Additionally, the data may comprise an indication of the pedal set the pressed pedal is associated with. Depending on how much a pedal has been displaced by the operator from its idle position is indicated by the data, different displacement causing different rotating speeds for the tracks. Idle position is referring here to the situation where a pedal / pedals are not being pressed by the operator.

[0036] The controller determines a control signal for moving tracks of the tracked vehicle based on the obtained measured displacement data. The obtained measured data may be analysed by the controller. The control signal may be determined based on a displacement, e.g. by a distance of the displacement, of a pedal that has been pressed, based on which pedal has been displaced, based on which pedal set the pressed pedal is belonging to, and on whether more than one pedal is pressed simultaneously. It should be noted that in some situations the number of pedals pressed simultaneously may be more than one.

[0037] The control signal may be configured to cause at least one of the following:

[0038] - the first track and the second track to rotate in a common direction at the same speed when the obtained measured displacement data comprises measured displacement data of a pedal of the first pedal set, or

[0039] - the first track and the second track to rotate in opposite directions at the same speed when the obtained measured displacement data comprises measured displacement data of a pedal of the second pedal set, or

[0040] - the first track and the second track to rotate in a common direction at different speeds when the obtained measured displacement data comprises measured displacement of a pedal of the first pedal set and a pedal of the second pedal set. In this way the control signal may cause a movement of the tracks for moving the tracked vehicle

[0041] It should be noted that there may be further control signals in addition to the ones above. The determined control signal may be provided by the controller to one or more actuators of the vehicle which are operatively connected to the tracks for causing rotation of the tracks. Examples of an actuator in a tracked vehicle may be a hydraulic valve, a hydraulic pump, a motor, a hydraulic motor, an electric motor.

[0042] The control signal may be generated to cause the first track and the second track to rotate in a common direction at a same speed when the obtained measured displacement data comprises measured displacement data of a pedal of the first pedal set describes a situation when the operator of the vehicle is controlling the vehicle to move along a straight line in accordance with the heading of the vehicle. The control signal may be generated to cause the first track and the second track to rotate in opposite directions at a same speed when the obtained measured displacement data comprises measured displacement data of a pedal of the second pedal set describes a situation when the operator of the vehicle is controlling the vehicle to turn / adjust the heading of the vehicle, while remaining at the same location. The control signal may be generated to cause the first track and the second track to rotate in a common direction at different speeds when the obtained measured displacement data comprises measured displacement of a pedal of the first pedal set and a pedal of the second pedal set describes a situation when the operator of the vehicle is controlling the vehicle to move in a curved line. Here the track on the side towards which the operator wants to turn is being slowed down compared to another track. Alternatively, the track on the opposite side towards which the operator wants to turn is being sped up compared to another track.

[0043] In an example in accordance with at least some embodiments, the obtained measured displacement data of the method may comprise a measured displacement of a pedal of the first pedal set, a measured displacement of a pedal of the second pedal set and an extreme position for the pedal of the second pedal set , the control signal is configured to cause one of the tracks to stop while the other one continues rotating. In this way turning of the tracked vehicle may be effected even if pedals of both pedal sets are displaced. When the extreme position of the pedal of the second pedal set is released, movement of the tracked vehicle may be continued without a need for change of direction of rotation of the tracks by simply driving both of the tracks to the same direction.

[0044] Fig. 4 describes an example of a method 400 according to the first aspect. The method comprises obtaining 402 at a controller a measured displacement data of at least one pedal among two pedal sets of the tracked vehicle, and controlling 404 a speed of each of the tracks of the tracked vehicle based on a relative displacement of a pedal of the first pedal set and a pedal of the second pedal set.

[0045] According to a second aspect the is provided a controller comprising: means for obtaining a measured displacement data of at least one pedal among two pedal sets of the tracked vehicle, controlling a speed of each of the tracks of the tracked vehicle based on a relative displacement of a pedal of the first pedal set and a pedal of the second pedal set.

[0046] The controller may further comprise: means for determining a control signal based on the obtained measured displacement data, and means for performing at least one of the following: determining, based on the measured displacement of a pedal of the first pedal set, a control signal causing a first track of the tracked vehicle and a second track of the tracked vehicle to rotate in a common direction at a same speed, or determining, based on the measured displacement of a pedal of the second pedal set, a control signal causing the first track and the second track to rotate in opposite directions at a same speed, or determining, based on the measured displacement of a pedal of the first pedal set and the measured displacement of a pedal of the second pedal, a control signal causing the first track and the second track to rotate in a common direction at different speeds; means for providing the determined control signal to one or more actuators of the first track and the second track of the tracked vehicle.

[0047] Each pedal of the first pedal set and each pedal of the second pedal set of the controller may have two functionalities for controlling a movement of the tracked vehicle and the controller is caused to perform at least one of the following:

[0048] - determine which of a first functionality and a second functionality of the two functionalities for a first pedal of the first pedal set is applied for controlling the movement of the tracked vehicle based on a displacement of at least one pedal of the second pedal set; or

[0049] - determine which of a first functionality and a second functionality of the two functionalities for a second pedal of the first pedal set is applied for controlling the movement of the tracked vehicle based on a displacement of at least one pedal of the second pedal set; or

[0050] - determine which of a first functionality and a second functionality of the two functionalities for a first pedal of the second pedal set is applied for controlling the movement of the tracked vehicle based on a displacement of at least one pedal of the first pedal set; or

[0051] - determine which of a first functionality and a second functionality of the two functionalities for a second pedal of the second pedal set is applied for controlling the movement of the tracked vehicle based on a displacement of at least one pedal of the first pedal set.

[0052] The first pedal of the first pedal set of the controller may be determined to have a first functionality of the two functionalities, based on determining that the first pedal of the first pedal set is displaced without another pedal of the second pedal unit is displaced at the same time, and the first pedal of the first pedal set is determined to have a second functionality of the two functionalities, based on determining that the first pedal of the first pedal set is displaced and another pedal of the second pedal unit is displaced at the same time; or the second pedal of the first pedal set is determined to have a first functionality of the two functionalities, based on determining that the second pedal of the first pedal set is displaced without another pedal of the second pedal unit is displaced at the same time, and the second pedal of the first pedal set is determined to have a second functionality of the two functionalities, based on determining that the second pedal of the first pedal set is displaced and another pedal of the second pedal unit is displaced at the same time.

[0053] The displacement data obtained at the controller comprises information describing the at least one pedal which has been displaced by the operator. Additionally, the displacement data further comprises the distance of displacement of the at least one pedal. When a pedal of the first pedal set is pressed, the displacement data comprises information indicating which pedal of the first pedal set is pressed and the distance of the displacement. The same applies correspondingly for the second pedal set. Furthermore, when a pedal of the first pedal set and the second pedal set are pressed, the displacement data comprises information indicating which pedals of the first pedal set and the second pedal set are pressed and the distances of the displacements.

[0054] Means for obtaining a measured displacement data of a pedal unit of at least one pedal among two pedal sets of the tracked vehicle may comprise e.g. a receiver / transceiver for wired and / or wireless communication, or any other suitable means for receiving a data describing displacement of a pedal / pedals.

[0055] Means for determining a control signal for moving tracks of the tracked vehicle based on the obtained measured displacement data may comprise a computer program code, a memory and a processor configured to execute the computer program code stored in the memory. The determination is performed based on the obtained measured displacement data.

[0056] Means for providing the control signal to at least one actuator of the tracked vehicle comprises a transmitter / transceiver for wired and / or wireless communication or any other suitable means for providing a control signal determining how the tracks of a tracked vehicle to rotate. Thus, the control signal may comprise information on which valves / valve should allow a hydraulic fluid to flow, each valve having a certain effect on the movement of the tracks of the tracked vehicle. The control signal may further comprise information on how much the dedicated valves should allow the hydraulic fluid to flow. In addition to the at least one valve of the vehicle, the control signal may be provided to other components of the vehicle such as a hydraulic pump, a motor associated with the vehicle, or any other suitable means configured to move a track and / or tracks of a tracked vehicle. It should be noted that the tracks of a tracked vehicle may be moved additionally or alternatively by electric motors.

[0057] Each pedal of the first pedal set and each pedal of the second pedal set have two functionalities for controlling a movement of the tracked vehicle and the controller is caused to perform at least one of the following: determine which of a first functionality and a second functionality of the two functionalities for a first pedal of the first pedal set is applied for controlling the movement of the tracked vehicle based on a displacement of at least one pedal of the second pedal set; or determine which of a first functionality and a second functionality of the two functionalities for a second pedal of the first pedal set is applied for controlling the movement of the tracked vehicle based on a displacement of at least one pedal of the second pedal set; or determine which of a first functionality and a second functionality of the two functionalities for a first pedal of the second pedal set is applied for controlling the movement of the tracked vehicle based on a displacement of at least one pedal of the first pedal set; or determine which of a first functionality and a second functionality of the two functionalities for a second pedal of the second pedal set is applied for controlling the movement of the tracked vehicle based on a displacement of at least one pedal of the first pedal set. In this way functionality of pedal of pedal sets may be determined

[0058] A first functionality of a pedal of a pedal set may be determined based on determining that the pedal is pressed without another pedal of another pedal set being pressed at the same time. The first functionality may be determined for each pedal of different pedal sets. Changing the displacement of the displaced pedal will result in a change of the speed in which the corresponding action is executed. E.g. the moving speed forwards or backwards or the speed of rotation clockwise or counterclockwise.

[0059] Examples of a first functionality of a pedal of a first pedal set comprise controlling tracks of the tracked vehicle to cause the tracked vehicle to move forwards or backwards depending on whether the displaced pedal is the first pedal of the first pedal set or the second pedal of the first pedal set.

[0060] Examples of a first functionality of a pedal of a second pedal set comprise controlling tracks of the tracked vehicle to cause rotating the tracked vehicle at a current position of the vehicle on the ground, whereby a heading of the tracked vehicle may be changed by execution of the functionality. The tracked vehicle may be rotated e.g. in a clockwise direction or counter-clockwise direction. It should be noted that the second pedal set may comprise the first pedal for rotating the tracked vehicle clockwise and a second pedal for rotating the tracked vehicle counter-clockwise.

[0061] A second functionality is determined based on determining that a pedal of a pedal set of a pedal unit is pressed and another pedal of another pedal set of the pedal unit being pressed at the same time.

[0062] Examples of a second functionality of a pedal of the second pedal set comprise that the tracks of the tracked vehicle are controlled to cause a curved path of movement of the tracked vehicle forwards, or backwards. In an example, the curved path of movement of the tracked vehicle forwards, or backwards may be caused, when the first functionality of the pedal of the first pedal set has been determined. The movement forwards may be determined based on which pedal, e.g. a first pedal or a second pedal, of the first pedal set has been displaced. The curved path of movement is about a centre of curvature of the curved path of movement. It should be noted that a change of displacement of the pedal of the second pedal set may cause a change of a curvature of the curved path of movement. It should be noted that a direction of the curvature, e.g. clockwise or counter-clockwise, may be selected based on which pedal of the second pedal set is displaced and determined to have the second functionality, e.g. a first pedal or a second pedal of the second pedal set.

[0063] In an example, when the second functionality of the pedal of the second pedal set has been determined, a change of a displacement of the pedal causes a change of curvature of the curved path of movement.

[0064] Examples of a second functionality of a pedal of the first pedal set comprise that the tracks of the tracked vehicle are controlled to cause a change of an angular speed of the tracked vehicle about a centre of curvature of a curved path of movement of the tracked vehicle. In an example, the change of angular speed may be caused, when the second functionality of the pedal of the first pedal set has been determined.

[0065] In an example, when the second functionality of the pedal of the first pedal set has been determined, a change of a displacement of the pedal in the pedal of the first pedal set causes a change of an angular speed of the tracked vehicle about a centre of curvature of a curved path of movement of the tracked vehicle.

[0066] In an example, the change of a displacement of the pedal of the first pedal set and / or of the change of a displacement of the pedal of the second pedal set may be determined based on obtaining a further measured displacement of the pedal indicating an increase of a previous measured displacement of the pedal or a decrease of a previous measured displacement of the pedal.

[0067] In an example, the curvature of a path of movement of the tracked vehicle about the centre of curvature of the curvature may be changed. When a first pedal of a first pedal set is pressed for causing a movement of the tracked vehicle forwards and a first pedal of a second pedal set is pressed for causing a turn of the tracked vehicle about the centre of curvature of the curvature path, a curved path of movement of the tracked vehicle is caused. When a displacement of the first pedal of the second pedal set of the pedal unit is adjusted, e.g. the first pedal is pressed further or at least partially released, and at the same time the first pedal of a first pedal set is being pressed without a substantial change to its position, the curvature of a path of movement of the tracked vehicle about the centre of curvature of the curvature path may be changed. The curvature of a path of movement of the tracked vehicle about a centre of curvature of the curvature path may be controlled to change to another direction of movement, e.g. backwards, in a similar manner.

[0068] When a first pedal of a first pedal set is pressed for causing a movement of the tracked vehicle forwards and a first pedal of a second pedal set is pressed for causing a turn of the tracked vehicle about the centre of curvature of the curvature path, a curved path of movement of the tracked vehicle is caused. Similarly, when a second pedal of the first pedal set is pressed causing a movement of the tracked vehicle backwards and a first pedal of a second pedal set is pressed for a turn of the tracked vehicle about the centre of curvature of the curvature path, a curved path of movement of the tracked vehicle is caused. In both of these scenarios, if the second pedal of the second pedal set is chosen, the turn of the tracked vehicle occurs towards another direction e.g. counterclockwise.

[0069] When the first pedal of the second pedal set is pressed further or at least partially released, and at the same time the first pedal of the second pedal set is being pressed without a substantial change to its position, the angular speed of the tracked vehicle may be changed. In this way the angular speed to one direction of rotation, e.g. clockwise, may be controlled. An angular speed of the tracked vehicle may be controlled to another direction of rotation in a similar manner. Accordingly, in an example, an angular speed of the tracked vehicle to another direction of rotation, e.g. counter-clockwise, may be changed, when a second pedal of a second pedal set is pressed for causing a rotation of the tracked vehicle to said another direction and a second pedal of a first pedal set is pressed for causing an advancement of the tracked vehicle either forwards or backwards, whereby curved path of movement of the tracked vehicle is results. When the second pedal of the second pedal set is pressed further or at least partially released, and at the same time the second pedal of the first pedal is being pressed without a substantial change to its position, the angular speed of the tracked vehicle may be changed. It should be noted that a direction of the tracked vehicle along the curved path of movement may be determined based which pedal, the first pedal or the second pedal, of the second pedal set is pressed. Further examples of the functionalities of a pedal comprise that the tracks of the tracked vehicle are controlled to cause a change of a curvature of a path of

[0070] movement of the tracked vehicle about a centre of curvature of the curvature path.

[0071] Table 1: Determined control signals provided by the controller to the actuators for moving the tracks of a tracked vehicle based on measured pedal displacements.

[0072] Table 1 comprising examples of combinations between the pressed pedals. Abbreviations: FW, forwards; BW, backwards, CW, clockwise; CCW, counterclockwise; NA, not applicable. It should be noted that in situations wherein two pedals of different pedal sets are pressed simultaneously, the clockwise and counterclockwise curvature of the path are seen as looked towards the direction indicated by the pedal of the first pedal set.

[0073] In an example when the first functionality of the first pedal set is utilised, either the first pedal of the first pedal set is displaced, or the second pedal of the first pedal set is displaced. The displacement of the first pedal will result in a movement of the tracked vehicle forwards and the displacement of the second pedal will result in a movement of the tracked vehicle backwards. The distance the pedal is displaced from the initial position of the pedal indicates the speed the vehicle will move forwards or backwards. The movement utilising the first functionality of a pedal of the first pedal set causes the tracks to rotate in a common direction at a common speed.

[0074] In an example when the first functionality of the second pedal set is utilised, either the first pedal of the second pedal set is displaced, or the second pedal of the second pedal set is displaced. The displacement of the first pedal will result in a rotation of the tracked vehicle clockwise and the displacement of the second pedal will result in a rotation of the tracked vehicle counterclockwise. The distance the pedal is displaced from the initial position of the pedal indicates the speed the vehicle will rotate clockwise or counterclockwise. The rotation utilising the first functionality of a pedal of the second pedal set causes the tracks to rotate in opposite directions at a common speed.

[0075] In an example, when the second functionality of a pedal set is utilised, a pedal from each pedal set is displaced. The displacement of a pedal in the first pedal set determines a speed and a common direction for the tracks to rotate. The displacement of a pedal in the second pedal set determines the difference between the speed of the first trach and the second track of the tracked vehicle causing the vehicle to follow a curvature path. Changing the displacement of the pressed pedal of the first pedal set changes the angular speed of the tracked vehicle along the curvature path. Changing the displacement of the pressed pedal of the second pedal set changes the curvature of the curvature path.

[0076] The Table 1 illustrates which control signal is provided by the controller to the actuators causing the tracks to move when a pedal or a combination of pedals is / are displaced. When the second functionality of a pedal is applied, the relative displacement of the pedals i.e. how much the pedals are pressed results in an information in the control signal describing the relative speed at which each of the tracks are rotated forwards / backwards. When the first functionality is applied, the relative displacement of the displaced pedal indicates the intensity / speed of movement / rotation of each track, the speed being equal among the tracks. In other words, the control signal indicates for each actuator at which speed the track driven by the actuator should rotate and in which direction.

[0077] It should be appreciated that a pedal of a pedal set may be a tilt pedal that is configured to be displaced by pressing the pedal at one side of an axis, or attachment point, of the pedal, or the pedal may be a rocker pedal that is configured to be displaced by pressing the pedal at opposite side sides of an axis, or attachment point, of the rocker pedal. A rocker pedal may serve for two tilt pedals since a displacement of the rocker pedal to one side of the of an axis may serve for a displacement of one tilt pedal and a displacement of the rocker pedal to another side of the of the axis may serve for a displacement of another tilt pedal.

[0078] According to a third aspect there is provided a tracked vehicle comprising a controller according to the second aspect at least two pedal sets wherein the tracked vehicle is configured to perform the method according to the first aspect.

[0079] A tracked vehicle may refer here to a civil engineering machine such as an excavator piling rig, drilling rig having at least two tracks for moving the vehicle. The controller, the pedal unit, valves, the hydraulic pump, and the hydraulic motors are associated with the tracks, enabling relevant features to control the movement of the tracks.

[0080] According to a further aspect there is provided a pedal unit comprising a first pedal set and a second pedal set each comprising at least one pedal, means for determining a displacement of the pedals, and means for providing measured displacement data. The pedal unit may be connected to the controller according of the second aspect, whereby the controller may obtain one or more measured displacements, or measured displacement data, of the first pedal set and the second pedal set for determining at least one control signal for moving tracks of the tracked vehicle based on the obtained measured displacement data.

[0081] In an example, the pedal unit may provide: the determined displacement of a pedal of the first pedal set to the controller, which causes the controller to determine a control signal causing the first track and the second track to rotate in a common direction at the same speed, or the determined displacement of a pedal of the second pedal set to the controller, which causes the controller to determine a control signal causing the first track and the second track to rotate in opposite directions at the same speed, or the determined displacement of a pedal of the first pedal set and a pedal of the second pedal set to the controller, which causes the controller to determine a control signal causing the first track and the second track to rotate in a common direction at different speeds.

[0082] Means for determining a displacement of a pedal may comprise e.g. a sensor or a set of sensors. The sensors measure how much a pedal has been pressed by an operator to determine the measured displacement data. The sensors are sensors that are suitable for measuring the displacement of a pedal such as one or more of: a force sensor, a rotation sensor, a position sensor, a photo optic sensor.

[0083] The displacement data provided for a controller comprises information describing the at least one pedal which has been displaced by the operator. Additionally, the displacement data further comprises the distance of displacement of the at least one pedal. When a pedal of the first pedal set is pressed, the displacement data comprises information indicating which pedal of the first pedal set is pressed and the distance of the displacement. The same applies correspondingly for the second pedal set. Furthermore, when a pedal of the first pedal set and the second pedal set are pressed, the displacement data comprises information indicating which pedals of the first pedal set and the second pedal set are pressed and the distances of the displacements.

[0084] Fig. 5 describes an exemplary block diagram 500 according to the invention describing. The presented process / method / flow may be performed at the controller of the second aspect in a continuous manner and / or periodically for determining a control signal for moving tracks of a tracked vehicle. The tracked vehicle comprises a first pedal set and a second pedal set of which each may comprise two pedals. Displacements of the pedals may be measured, and the measured displacements may be obtained as described in step 402. Now referring to the block diagram 500, the flow comprises step 502 of determining if measured displacement data of a pressed pedal is obtained at the controller. If the measured displacement data is not obtained, the flow proceeds to step 504 and a control signal for moving tracks of the tracked vehicle is not generated. Alternatively, if the obtained measured displacement data is obtained in step 502, the flow proceeds to step 506. The step 506 may comprise determining if the obtained measured displacement data comprises or indicates displacements of pedals of both pedal sets of the tracked vehicle. Thus, the obtained measured displacement data may comprise measured displacement data of a pedal of the first pedal set and measured displacement data of a pedal of the second pedal set. If it is determined in step 506 that the obtained measured displacement data is obtained from both pedal sets, the flow proceeds to step 508.

[0085] The step 508 comprises determining if the pressed pedal of the second pedal set is the first pedal of the second pedal of the second pedal set. If the pressed pedal of the second pedal set is the first pedal, the process proceeds to the step 510. Alternatively, if the pressed pedal of the second pedal set is the second pedal, the flow proceeds to the step 512. In other words, the step 510 describes applying the first functionality of the second pedal set and the step 512 describes applying the second functionality of the second pedal set. Steps 510 and 512 comprises providing / generating a control signal causing the first track and the second track to rotate in opposite directions at different speeds. The speed of each track may be determined based on the measured displacement of the pedal of the first pedal set and the measured displacement of the pedal of the second pedal set and their mutual relationship. Generating the control signal causing the tracks to rotate in opposite directions at different speeds causes the tracked vehicle to turn its heading efficiently. At step 510, the controller determines / provides / generates a control signal that causes the first track and the second track of the tracked vehicle to rotate in a common direction at different speeds. The direction of desired curvature of a moving path for the tracked vehicle indicated by the first pedal of the second pedal set is performed by applying a slower speed for the track on the respective side of the curve of the curvature path being the first track of the tracked vehicle. Thus, the rotation speed of the first track is slower than the rotation speed of the second track. At step 512, the controller determines / provides / generates a control signal that causes the first track and the second track of the tracked vehicle to rotate in a common direction at different speeds. The direction of desired curvature of a moving path for the tracked vehicle indicated by the second pedal of the second pedal set is performed by applying a slower speed for the track on the respective side of the curve of the curvature path being the second track of the tracked vehicle. Thus, the rotation speed of the second track is slower than the rotation speed of the first track.

[0086] If it is determined in step 506 that the obtained measured displacement data is not obtained from both pedal sets, the flow proceeds to step 514. Step 514 comprises determining which of the first pedal set and the second pedal set has provided the measured displacement data is obtained from. If the obtained measured displacement data is obtained from the first pedal set, the flow proceeds to step 516. If the obtained measured displacement data is obtained from the second pedal set, the flow proceeds to step 518. Step 516 comprises providing a control signal causing the first track and the second track to rotate in a common direction at a same speed. In this way the tracked vehicle may be driven by simply operating a single pedal. Step 518 comprises providing a control signal causing the first track and the second track to rotate in a opposite directions at a same speed. In this way the tracked vehicle may be efficiently turned at the spot.

[0087] The present invention alleviates at least some of the problems discussed earlier. The disclosed invention according to the presented aspects improves the precision of controlling a tracked vehicle. For example, the vehicle may be operated by pressing a single pedal ensuring even acceleration of the rotation and the rotation of the tracks as the rotation of both tracks is caused simultaneously by the controller. The same applies to rotating of the vehicle in place, where the tracks may be caused to begin the rotation in opposite directions simultaneously and at a common speed. Furthermore, the second functionality of the pedal sets ensures that from an even forwards / backwards movement it is convenient to make adjustments to the direction movement through a curvature path and to return to the even forwards / backwards movement after the change in the direction.

[0088] The exemplary embodiments presented in this text are not to be interpreted to pose limitations to the applicability of the appended claims. The verb "to comprise" is used in this text as an open limitation that does not exclude the existence of also unrecited features. The features recited in dependent claims are mutually freely combinable unless otherwise explicitly stated. The novel features which are considered characteristic of the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific example embodiments when read in connection with the accompanying drawings.

[0089] The invention has been explained above with reference to the aforementioned embodiments, and several advantages of the invention have been demonstrated. It is clear that the invention is not only restricted to these embodiments, but comprises all possible embodiments within the spirit and scope of the inventive thought and the following patent claims. For example, even if certain kinds of sensors are mentioned, it is to be noted that also other suitable types of sensors can also be used.

Claims

CLAIMS1 . A method for moving a tracked vehicle comprising: obtaining at a controller (118) a measured displacement data of at least one pedal among two pedal sets (110, 112) of the tracked vehicle characterised in that the two pedal sets comprise a first pedal set and a second pedal set comprising at least two functionalities for moving the tracked vehicle, and controlling the speed of each of the tracks (138, 140) of the tracked vehicle based on a relative displacement of a pedal of the first pedal set (110) and a pedal of the second pedal set (112) comprising: o determining which of the at least two functionalities is applied based on the relative displacement; and o generating a control signal for controlling the speed of each of the tracks of the tracked vehicle according to the determined functionality.

2. The method of claim 1 , comprising: performing, at the controller, at least one of the following: determining, based on the measured displacement of a pedal of the first pedal set, a control signal causing a first track of the tracked vehicle and a second track of the tracked vehicle to rotate in a common direction at a same speed, or determining, based on the measured displacement of a pedal of the second pedal set, a control signal causing the first track and the second track to rotate in opposite directions at a same speed, or determining, based on the measured displacement of a pedal of the first pedal set and the measured displacement of a pedal of the second pedal, a control signal causing the first track and the second track to rotate in a common direction at different speeds;providing, at the controller, the determined control signal to one or more actuators (124, 126) of the first track and the second track of the tracked vehicle.

3. The method according to any of the preceding claims wherein: when the obtained measured displacement data comprises a measured displacement of a pedal of the first pedal set, a measured displacement of a pedal of the second pedal set and the measured displacement indicates an extreme position for the pedal of the second pedal set, the control signal is configured to cause one of the tracks to stop.

4. A controller comprising: means for obtaining a measured displacement data of at least one pedal among two pedal sets (110, 112) of the tracked vehicle characterised in that the two pedal sets (110, 112) comprise a first pedal set and a second pedal set comprising at least two functionalities for moving the tracked vehicle, means for controlling the speed of each of the tracks (138, 140) of the tracked vehicle based on a relative displacement of a pedal of the first pedal set (110) and a pedal of the second pedal set (112) comprising: o means for determining which of the at least two functionalities is applied based on the relative displacement; and o means for generating a control signal for controlling the speed of each of the tracks of the tracked vehicle according to the determined functionality.

5. The controller of claim 4, comprising means for determining a control signal based on the obtained measured displacement data, and means for performing at least one of the following:determining, based on the measured displacement of a pedal of the first pedal set, a control signal causing a first track of the tracked vehicle and a second track of the tracked vehicle to rotate in a common direction at a same speed, or determining, based on the measured displacement of a pedal of the second pedal set, a control signal causing the first track and the second track to rotate in opposite directions at a same speed, or determining, based on the measured displacement of a pedal of the first pedal set and the measured displacement of a pedal of the second pedal, a control signal causing the first track and the second track to rotate in a common direction at different speeds; means for providing the determined control signal to one or more actuators of the first track and the second track of the tracked vehicle.

6. The controller according to claim 5, wherein each pedal of the first pedal set and each pedal of the second pedal set have two functionalities for controlling a movement of the tracked vehicle and the controller is caused to perform at least one of the following:- determine which of a first functionality and a second functionality of the two functionalities for a first pedal of the first pedal set is applied for controlling the movement of the tracked vehicle based on a displacement of at least one pedal of the second pedal set; or- determine which of a first functionality and a second functionality of the two functionalities for a second pedal of the first pedal set is applied for controlling the movement of the tracked vehicle based on a displacement of at least one pedal of the second pedal set; or- determine which of a first functionality and a second functionality of the two functionalities for a first pedal of the second pedal set is appliedfor controlling the movement of the tracked vehicle based on a displacement of at least one pedal of the first pedal set; or- determine which of a first functionality and a second functionality of the two functionalities for a second pedal of the second pedal set is applied for controlling the movement of the tracked vehicle based on a displacement of at least one pedal of the first pedal set.

7. The controller according to claim 6, wherein the first pedal of the first pedal set is determined to have a first functionality of the two functionalities, based on determining that the first pedal of the first pedal set is displaced without another pedal of the second pedal set is displaced at the same time, and the first pedal of the first pedal set is determined to have a second functionality of the two functionalities, based on determining that the first pedal of the first pedal set is displaced and another pedal of the second pedal set is displaced at the same time; or the second pedal of the first pedal set is determined to have a first functionality of the two functionalities, based on determining that the second pedal of the first pedal set is displaced without another pedal of the second pedal set is displaced at the same time, and the second pedal of the first pedal set is determined to have a second functionality of the two functionalities, based on determining that the second pedal of the first pedal set is displaced and another pedal of the second pedal set is displaced at the same time.

8. A tracked vehicle comprising: at least two pedal sets and a controller according to any of claims 4-7, the tracked vehicle being configured to perform the method according to any of claims 1-3.

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