Computer system and method for controlling electric propulsion system of autonomous working machine

Abstract

Computer systems and methods for controlling an electric propulsion system of an autonomous working machine are disclosed. An electric propulsion system (200) for an autonomous work machine (100) comprising a first axle (110) and a second axle (120), the electric propulsion system (200) comprising a first power system (210) configured to drive the first axle, the first power system comprising a first electrical energy storage system (211a, 211b), a second power system (220) configured to drive the second axle, the second power system comprising a second electrical energy storage system (221a, 221b). The method includes determining a longitudinal slope along an expected travel path, determining charge levels of the first and second electrical energy storage systems, respectively, controlling the work machine to assume a first orientation or a second orientation to travel along the expected travel path, wherein the orientation of the work machine is controlled according to the determined longitudinal gradient and the determined charge level.

Description

Technical Field

[0001] The present disclosure generally relates to control of an electric propulsion system in an autonomous work machine. In particular aspects, the present disclosure relates to a computer system and method for controlling an electric propulsion system of an autonomous work machine. The present disclosure may be applicable to heavy work machines and construction equipment, as well as other vehicle types. Although the present disclosure may be described with respect to a particular work machine, the present disclosure is not limited to any particular work machine. Background Art

[0002] Heavy electric work machines such as electric transporters and dump trucks typically include more than one driven axle, such as two driven axles. Such work machines may include a single power system that powers both axles, or include separate power systems, each of which powers one of the axles. A problem that may arise when separate power systems are provided is that the battery packs of the respective power systems may discharge unevenly, i.e., the battery pack used to power the rear axle of the work machine may discharge faster than the battery pack used to power the front axle. Therefore, charging may need to be stopped before the battery pack used to power the front axle is fully discharged. Summary of the invention

[0003] According to a first aspect of the present disclosure, there is provided a computer system comprising a processing circuit configured to control an electric propulsion system of an autonomous working machine, the autonomous working machine comprising a first axle located near a first end of the working machine and a second axle located near a second end of the working machine. The electric propulsion system comprises: - a first electric power system configured to drive the first axle, the first electric power system comprising a first electric energy storage system and a first electric motor, - A second electrical power system configured to drive the second axle, the second electrical power system comprising a second electrical energy storage system and a second electric motor.

[0004] The processing circuit is configured to: - determine the longitudinal slope along the intended travel path of the machine, - determining the charge levels of the first energy storage system and the second energy storage system, respectively, - Controlling the work machine to adopt a first orientation or a second orientation to travel along the expected travel path, the first end of the work machine being the front end in the first orientation and the second end of the work machine being the front end in the second orientation, wherein the orientation of the work machine is controlled based on a determined longitudinal slope and a determined power level.

[0005] A first aspect of the present disclosure may seek to provide a system for controlling an electric propulsion system that is improved in at least some respects, the electric propulsion system comprising two separate electrical power systems configured to drive two separate axles. Specifically, the first aspect may seek to provide such a system that can reduce the problem of unbalanced charge levels between the respective energy storage systems of the two electrical power systems and therefore can increase the time between charging stops. By controlling the work machine to assume a certain orientation based on the charge level and the grade of the road, the orientation can be selected to balance the charge level between the energy storage systems. For an autonomous work machine, an orientation of driving uphill or downhill can therefore be selected to achieve charge balancing purposes. Technical benefits can include increasing the overall battery range of the work machine.

[0006] Optionally, in some examples, including in at least one preferred example, the processing circuit is further configured to: - detecting uphill sections along the expected driving path, - in response to determining that the charge level of the first electrical energy storage system exceeds the charge level of the second electrical energy storage system by at least a first threshold amount, controlling the work machine to assume the second orientation before entering the detected uphill segment, and - In response to determining that the charge level of the second electrical energy storage system exceeds the charge level of the first electrical energy storage system by at least the first threshold amount, controlling the work machine to assume the first orientation prior to entering the detected uphill segment.

[0007] Thus, the orientation of the machine traveling through an uphill section may be selected so that the energy storage system with the lowest charge level provides less power during the uphill travel than the energy storage system with the highest charge level. This may help balance the charge levels. When it is determined that the difference in the charge levels of the energy storage systems is less than a first threshold amount, the machine may be controlled to maintain its current orientation. In this way, it may be ensured that an orientation change is initiated only when it is deemed useful.

[0008] Optionally, in some examples, including in at least one preferred example, the uphill section is a section where the vertical height increases by at least a first threshold height. In this way, it can be ensured that an orientation change is not initiated when the possibility for balancing the charge level is considered too low.

[0009] Optionally, in some examples, including at least one preferred example, the first threshold height is set according to the weight of the work machine, so that it decreases as the weight of the work machine increases. Therefore, the larger the payload of the work machine, the smaller the height difference required for the road section to be detected as an uphill section, before which the work machine needs to change its orientation.

[0010] Optionally, in some examples, including in at least one preferred example, the processing circuit is configured to: - detecting downhill sections along the intended travel path, - in response to determining that the charge level of the first electrical energy storage system exceeds the charge level of the second electrical energy storage system by at least a second threshold amount, controlling the work machine to assume the second orientation before entering the detected downhill segment, and - In response to determining that the charge level of the second electrical energy storage system exceeds the charge level of the first electrical energy storage system by at least the second threshold amount, controlling the work machine to assume the first orientation prior to entering the detected downhill segment.

[0011] Thus, the orientation of the work machine traveling through the downhill section can be selected so that the energy recovered during the travel along the downhill section is mainly used to charge the energy storage system with the lowest charge level. This can help to balance the charge levels. When it is determined that the difference in the charge levels of the energy storage systems is less than the second threshold amount, the work machine can be controlled to maintain its current orientation. In this way, it can be ensured that the orientation change is only initiated when it is considered useful.

[0012] Optionally, in some examples, including at least one preferred example, the downhill section is a section whose vertical height decreases by at least a second threshold height. Optionally, the second threshold height is set according to the weight of the work machine so that it decreases as the weight of the work machine increases.

[0013] Optionally, in some examples, including in at least one preferred example, the processing circuit is further configured to evaluate whether a predetermined condition for allowing the work machine to travel through the downhill section in the second orientation is met, wherein the processing circuit is only configured to control the work machine to adopt the second orientation when the predetermined condition is met. In this way, if the second orientation is not very suitable due to, for example, the configuration of the work machine and the slope of the road, it can be avoided that the work machine travels through the downhill section in the second orientation. This may be relevant, for example, if the work machine includes a tiltable body with an asymmetric design. In those cases, it may be safer to travel through the steep downhill section with the first end as the leading end to avoid the payload falling when the work machine has to brake.

[0014] Optionally, in some examples, including in at least one preferred example, the predetermined condition is related to the weight of the work machine and / or to the longitudinal slope in the downhill section.

[0015] Optionally, in some examples, including in at least one preferred example, the predetermined condition is deemed to be met when the longitudinal slope within the downhill section is below a threshold slope, and / or when the longitudinal slope is not expected to cause the work machine to be tilted above a threshold slope, and / or when the work machine weight is below a threshold weight.

[0016] According to a second aspect of the present disclosure, an autonomous working machine is provided, which includes or is communicatively connected to a computer system according to the first aspect. The autonomous working machine includes: a first axle located near the first end of the working machine; a second axle located near the second end of the working machine; and an electric propulsion system, the electric propulsion system including: a first power system configured to drive the first axle, the first power system including a first electric energy storage system and a first electric motor; and a second power system configured to drive the second axle, the second power system including a second electric energy storage system and a second electric motor. The second aspect of the present disclosure may seek to provide an autonomous working machine of this type that is improved in at least some aspects. Specifically, it may seek to provide an autonomous working machine that can reduce the problem of imbalance in power levels between the corresponding energy storage systems of the two power systems.

[0017] Optionally, in some examples, including at least one preferred example, the work machine includes a tiltable body configured to carry a payload, the tiltable body being pivotable about a transverse axis located at a second end of the work machine. Thus, the first end may correspond to a front end of the work machine, and the second end may correspond to a rear end.

[0018] According to a third aspect of the present disclosure, there is provided a computer-implemented method for controlling an electric propulsion system of an autonomous working machine, the autonomous working machine comprising a first axle located near a first end of the working machine and a second axle located near a second end of the working machine. The electric propulsion system comprises: - a first electric power system configured to drive the first axle, the first electric power system comprising a first electric energy storage system and a first electric motor, - A second electrical power system configured to drive the second axle, the second electrical power system comprising a second electrical energy storage system and a second electric motor.

[0019] The method includes: - determining, by processing circuitry of the computer system, the longitudinal slope along the intended travel path of the work machine, - determining, by the processing circuit, the charge levels of the first energy storage system and the second energy storage system, respectively, - The processing circuit controls the work machine to adopt a first orientation or a second orientation to travel along the expected travel path, the first end of the work machine is the front end in the first orientation, and the second end of the work machine is the front end in the second orientation, wherein the orientation of the work machine is controlled according to a determined longitudinal slope and a determined power level.

[0020] The advantages and effects of the third aspect of the present disclosure are similar to those of the first and second aspects of the present disclosure, and vice versa.

[0021] Optionally, in some examples, including in at least one preferred example, the method comprises: - detecting, by the processing circuit, an uphill section along the expected travel path, - in response to determining that the charge level of the first electrical energy storage system exceeds the charge level of the second electrical energy storage system by at least a first threshold amount, controlling, by the processing circuit, the work machine to assume the second orientation before entering the detected uphill segment, and - In response to determining that the charge level of the second electrical energy storage system exceeds the charge level of the first electrical energy storage system by at least the first threshold amount, controlling, by the processing circuit, the work machine to assume the first orientation prior to entering the detected uphill segment.

[0022] Optionally, in some examples, including in at least one preferred example, detecting the uphill section includes detecting a section whose vertical height increases by at least a first threshold height.

[0023] Optionally, in some examples, including in at least one preferred example, the first threshold height is set according to the weight of the work machine, such that it decreases as the weight of the work machine increases.

[0024] Optionally, in some examples, including in at least one preferred example, the method comprises: - detecting, by the processing circuit, a downhill section along the expected travel path, - in response to determining that the charge level of the first electrical energy storage system exceeds the charge level of the second electrical energy storage system by at least a second threshold amount, controlling, by the processing circuit, the work machine to assume the second orientation before entering the downhill segment, and - In response to determining that the charge level of the second electrical energy storage system exceeds the charge level of the first electrical energy storage system by at least the second threshold amount, controlling, by the processing circuit, the work machine to assume the first orientation prior to entering the detected downhill segment.

[0025] Optionally, in some examples, including in at least one preferred example, detecting the downhill section includes detecting a section whose vertical height decreases by at least a second threshold height.

[0026] Optionally, in some examples, including in at least one preferred example, the method further comprises: - evaluating, by the processing circuit, whether a predetermined condition for allowing the work machine to travel through the downhill section in the second orientation is met, The working machine is controlled to adopt the second orientation only when the predetermined condition is met.

[0027] Optionally, in some examples, including at least one preferred example, the predetermined condition is related to the work machine heavy payload and / or to the longitudinal slope in the downhill section.

[0028] Optionally, in some examples, including in at least one preferred example, the predetermined condition is deemed to be met when the longitudinal slope within the downhill section is below a threshold slope, and / or when the longitudinal slope is not expected to cause the work machine to be tilted above a threshold slope, and / or when the work machine weight is below a threshold weight.

[0029] According to a fourth aspect of the present disclosure, a computer program product is provided. The computer program product comprises a program code. The program code is used to perform any one of the methods in the examples of the third aspect of the present disclosure when the program code is executed by the processing circuit.

[0030] According to a fifth aspect of the present disclosure, there is provided a non-transitory computer-readable storage medium comprising instructions, which, when executed by the processing circuit, causes the processing circuit to perform the method of any one of the examples of the third aspect of the present disclosure.

[0031] The disclosed aspects, examples (including any preferred examples), and / or the appended claims may be appropriately combined with each other, which is obvious to any person skilled in the art. Additional features and advantages are disclosed in the detailed description, claims, and drawings, and in part will be obvious to those skilled in the art or recognized by practicing the disclosure as described herein.

[0032] Also disclosed herein are computer systems, control units, code modules, computer-implemented methods, computer-readable media, and computer program products associated with the technical benefits discussed above. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Examples are described in more detail below with reference to the accompanying drawings.

[0034] Figure 1 is a schematic overview of an autonomous working machine and a computer system according to an example.

[0035] Figure 2 is a schematic side view of an autonomous working machine according to an example.

[0036] Figure 3 An autonomous working machine about to travel uphill is schematically shown.

[0037] Figure 4 is a flow chart illustrating a method according to an example.

[0038] Figure 5 is a schematic diagram of an exemplary computer system for implementing the examples disclosed herein, according to one example. DETAILED DESCRIPTION

[0039] The detailed description set forth below provides information and examples of the disclosed technology in sufficient detail to enable those skilled in the art to practice the disclosure.

[0040] The electric working machine may include two power systems, each of which powers one driven axle of the working machine (such as the front axle and the rear axle). Each power system includes its own energy storage system, which can be charged at a charging station, and the energy recovered during, for example, downhill driving can be stored in the energy storage system. Since the front and rear axle propulsion and energy recovery do not necessarily follow each other, even if the charge levels are equal after charging at the charging station, the charge levels of the front and rear axle energy storage systems will differ over time. A typical case of such a difference in charge level is driving uphill or downhill with poor traction. In these cases, traction must be distributed according to the standard force distribution in order to utilize the available friction. Therefore, the rear axle propulsion system consumes more power when driving uphill, and the front axle propulsion system recovers more power when driving downhill. This will deplete the rear axle energy storage system and cause charging to stop before the charge level of the front axle energy storage system is low.

[0041] For separate power systems, when the charge levels begin to differ from each other, it is usually impossible to transfer power from one energy storage system to the other energy storage system. Conversely, when one of the energy storage systems is depleted, charging must be stopped even if the other energy storage system still has available power.

[0042] In order to reduce downtime, it is desirable to provide a method and system that facilitates balancing the charge levels of two electrical energy storage systems.

[0043] Figure 1An autonomous work machine 100 communicatively connected to a computer system 400 according to an example of the present disclosure is schematically shown. The work machine 100 includes a first axle 110 located near a first end 101 of the work machine 100 and a second axle 120 located near a second end 102 of the work machine 100. A first pair of driven wheels 111, 112 are provided on the first axle 110, and a second pair of driven wheels 121, 122 are provided on the second axle 120. The work machine 100 also includes an electric propulsion system 200 for providing propulsion power for the work machine 100. The electric propulsion system 200 includes a first electric power system 210 configured to drive the first axle 110 and a second electric power system 220 configured to drive the second axle 120. The first electric power system 210 includes a first electrical energy storage system (including two first battery packs 211a, 211b herein) and a first electric motor 212. The second electric system 220 includes a second electric energy storage system (including two second battery packs 221a, 221b in this article) and a second electric motor 222. The first electric motor 212 is connected to the first axle 110 via the first transmission 113, and the second electric motor 222 is connected to the second axle 120 via the second transmission 123. The first electric motor 212 and the second electric motor 222 are in the form of motor-generators, which consume electricity when operating as motors and generate electricity in a regenerative operation mode.

[0044] Although the first power system 210 and the second power system 220 are shown herein as each having one electric motor 212, 222, in other examples according to the present disclosure, each power system may include more than one electric motor, such as each power system includes two or more electric motors. Similarly, each power system may include other numbers of battery packs, such as each power system includes one, three, or four battery packs. According to one example, each power system may include four battery packs and two electric motors.

[0045] The computer system 400 includes a processing circuit 402 and may be located on or off the work machine 100. For example, the computer system 400 may be a central server or a cloud server and is arranged to communicate with the onboard control unit 130 of the work machine 100. The communication link (indicated by the dashed arrow) between the computer system 400 and the control unit 130 of the work machine 100 may be in the form of wireless communication, such as by wireless communication using WiFi, Bluetooth, telecommunications, etc. The onboard control unit 130 may in turn be configured to communicate with different systems of the work machine 100, such as the first power system 210 and the second power system 220.

[0046] Figure 1 The autonomous working machine 100 shown in FIG. 1 may have, for example, Figure 2Thus, the work machine 100 may include a tiltable body 103 configured to carry a payload. The tiltable body 103 may pivot about a transverse axis (not shown) located at the second end 102 of the work machine 100. The transverse axis is herein parallel to the first axle 110 and the second axle 120.

[0047] The work machine 100 can be configured to operate in a restricted area, such as in a work site, a quarry, a mine, or the like. The field system of the restricted area can be used by the computer system 400. The field system can include a map of the restricted area, including a topographic map, from which the road slope along the known driving path of the work machine 100 is known. The computer system 400 can be configured to plan the driving path of the work machine 100 based on the information provided from the field system. The work machine 100 can also include at least one sensor 114 for identifying the position of the work machine 100 in the restricted area. The sensor 114 can be, for example, a GNSS (Global Navigation Satellite System) sensor. The sensor 114 can be configured to transmit the coordinates of the work machine 100 to the computer system 400. In addition or alternatively, other sensors (such as by using environmental perception sensors) can be used to locate the work machine 100 in the restricted area.

[0048] In addition, the work machine 100 may include at least one sensor 115 for detecting the weight of the work machine 100 and / or the weight of the load provided on the work machine 100 (i.e., the material loaded on the work machine 100). The sensor 115 may be, for example, a weight sensor that measures the weight of the load. Alternatively, by using a pressure sensor, the sprung mass of the work machine may be calculated based on the pressure measured in the hydraulic suspension system. In addition, a camera or the like that identifies the material loaded on the work machine 100 may also be provided. Data from the sensor 115 may be transmitted to the computer system 400.

[0049] Furthermore, the working machine 100 may include at least one sensor (not shown) that can be used to determine the current orientation of the working machine. The sensor may be, for example, a rotation speed sensor configured to sense the rotation speed of any of the wheels 111 , 112 , 121 , 122 of the working machine 100 .

[0050] Figure 3 An autonomous working machine 100 is shown about to travel through an expected travel path 1, such as Figure 1 and / or Figure 2 In the work machine 100 shown in FIG. 1 , the expected travel path 1 includes an uphill section 2 and a subsequent downhill section 3. The work machine 100 is positioned so that its first end 101 is the front end.

[0051] The processing circuit 402 is configured to determine the longitudinal slope along the expected travel path 1 of the work machine 100, that is, the slope of the ground along the travel direction v of the work machine 100. For example, it can use the data provided from the sensor 114 to locate the work machine 100 in the restricted area, and determine the slope along the expected travel path 1 based on the location and map of the restricted area.

[0052] The processing circuit 402 is also configured to determine the charge level of the first energy storage system and the second energy storage system (i.e., the first battery pack 211a, 211b and the second battery pack 221a, 221b), respectively. The charge level herein may be understood as the state of charge (SoC) of the corresponding energy storage system. The charge level may be determined based on data transmitted from the battery packs 211a, 211b, 221a, 221b.

[0053] The processing circuit 402 is also configured to control the working machine 100 to take a first orientation or a second orientation to travel along the expected travel path. Figure 3 As shown in FIG. 1 , the first end 101 of the work machine 100 is the front end, and in the second orientation, the second end 102 of the work machine 100 is the front end. The orientation of the work machine 100 is controlled based on the determined longitudinal slope and the determined power level.

[0054] In one example, an uphill section 2 along the expected travel path 1 may be detected, such as a section where the vertical height h increases by at least a first threshold height h1. In addition, it may be determined that the charge level of the first electrical energy storage system 211a, 211b exceeds the charge level of the second electrical energy storage system 221a, 221b by at least a first threshold amount. In response, the processing circuit 402 may control the work machine 100 to take a second orientation before entering the detected uphill section 2. In other words, the work machine 100 may travel upward along the uphill section 2 in the second orientation, with the second end 102 being the front end. The first electric motor 212 driving the first axle 110, which is located at a lower level than the second axle 120 during the climb, therefore consumes more power than the second electric motor 222 during the climb. This may help balance the charge levels because the charge level of the first electrical energy storage system 211a, 211b will drop faster than the charge level of the second electrical energy storage system 221a, 221b.

[0055] Therefore, if it is determined that the charge level of the second energy storage system 221a, 221b exceeds the charge level of the first energy storage system 211a, 211b by at least the first threshold amount, the processing circuit 402 can control the work machine 100 to assume the first orientation before entering the detected uphill section 2.

[0056] If the difference between the charge levels of the first energy storage systems 211a, 211b and the second energy storage systems 221a, 221b is less than a first threshold amount, the work machine 100 can be controlled to climb along the detected uphill section 2 without changing its orientation before climbing the slope.

[0057] The first threshold height h1 can be set according to the weight of the work machine (i.e., the weight of the work machine 100) so that it decreases as the weight of the work machine increases. If the work machine 100 is relatively light, a relatively large change in vertical height h is required to change the orientation of the work machine 100, while for a relatively heavy work machine 100, a relatively small change in vertical height h is required to change the orientation. The heavier the work machine 100, the greater the difference between the power consumed by the frontmost electric motor and the rearmost electric motor.

[0058] In another example, a downhill section 3 along the expected travel path 1 may be detected, such as a section where the vertical height h decreases by at least a second threshold height h2. In addition, it may be determined that the charge level of the first energy storage system 211a, 211b exceeds the charge level of the second energy storage system 221a, 221b by at least a second threshold amount. In response, the processing circuit 402 may control the work machine 100 to take a second orientation before entering the detected downhill section 3. In other words, the work machine 100 may travel down the downhill section 3 in the second orientation, with the second end 102 being the front end. The first electric motor 212 connected to the first axle 110, which is located at a higher level than the second axle 120 during the downhill period, therefore generates less power than the second electric motor 222 during the downhill period. This may help balance the charge levels because the charge levels of the first energy storage system 211a, 211b will increase more slowly than the charge levels of the second energy storage system 221a, 221b.

[0059] Therefore, if it is determined that the charge level of the second energy storage system 221a, 221b exceeds the charge level of the first energy storage system 211a, 211b by at least a second threshold amount, the processing circuit 402 can control the work machine 100 to assume the first orientation before entering the detected downhill section 3.

[0060] If the difference between the charge level of the first energy storage system 211a, 211b and the charge level of the second energy storage system 221a, 221b is less than the second threshold amount, the work machine 100 can be controlled to go downhill along the detected downhill section 3 without changing its orientation before going downhill. The second threshold amount may be equal to the first threshold amount, or it may be different from the first threshold amount.

[0061] Similar to the first threshold height h1, the second threshold height h2 can be set according to the weight of the work machine so that it decreases as the weight of the work machine increases. The first threshold height and the second threshold height can be the same or different.

[0062] The processing circuit 402 may also be configured to evaluate whether a first predetermined condition for allowing the work machine 100 to travel through the downhill section 3 in a second orientation is satisfied. If the first predetermined condition is satisfied, the work machine 100 may be controlled to assume the second orientation. In this example, if the first predetermined condition is not satisfied, the work machine 100 will not be allowed to travel downhill along the downhill section 3 in the second orientation. The first predetermined condition may be related to the weight of the work machine and / or to the longitudinal slope within the downhill section 3. For example, the first predetermined condition may be considered to be satisfied when the longitudinal slope within the downhill section 3 is below a threshold slope, and / or when the longitudinal slope is not expected to cause the longitudinal inclination of the work machine 100 to exceed a threshold inclination, and / or when the weight of the work machine is below a threshold weight. By setting such a condition, a situation in which a heavily loaded work machine 100 travels downhill in an inappropriate orientation may be avoided. For example, when the work machine 100 includes a Figure 2 When the tiltable body 103 shown in FIG. 1 is tilted, depending on the configuration of the tiltable body 103, the material loaded on the tiltable body 103 may fall off the body during downhill travel if the work machine 100 suddenly brakes. Therefore, it may be more appropriate for the work machine 100 to travel downhill in the first orientation.

[0063] Similarly, when an uphill section 2 is detected, the processing circuit 402 may also be configured to evaluate whether a second predetermined condition for allowing the work machine 100 to travel through the uphill section 2 in a first orientation is met. If the second predetermined condition is met, the work machine 100 may be controlled to take the first orientation. In this example, if the second predetermined condition is not met, the work machine 100 will not be allowed to go uphill along the uphill section 2 in the first orientation. The second predetermined condition may be set to avoid the payload from falling as the work machine accelerates in the direction of travel during uphill travel. Therefore, the second predetermined condition may be related to the weight of the work machine and / or to the longitudinal slope within the uphill section 2. The risk of the payload falling during uphill travel is generally lower than that during downhill travel because the magnitude of the acceleration is generally lower than the magnitude of the deceleration in a sudden braking event during downhill travel. Therefore, for downhill travel, the second predetermined condition may be set to allow a steeper slope and a larger payload than the first predetermined condition.

[0064] Figure 4 Schematically shows a method for controlling an autonomous working machine 100 (such as Figures 1 to 3 A computer-implemented method for an electric propulsion system 200 of a working machine (as shown in any one of the examples). The method includes the following actions, which can be taken in any suitable order.

[0065] S1 : The processing circuit 402 of the computer system 400 determines the longitudinal slope along the expected travel path 1 of the work machine 100 .

[0066] S2: The processing circuit 402 determines the power levels of the first energy storage system 211a, 211b and the second energy storage system 221a, 221b respectively.

[0067] S3: The processing circuit 402 controls the work machine 100 to adopt a first orientation or a second orientation to travel along the expected driving path 1, the first end 101 of the work machine 100 is the front end in the first orientation, and the second end 102 of the work machine 100 is the front end in the second orientation, wherein the orientation of the work machine 100 is controlled according to a determined longitudinal slope and a determined power level.

[0068] The method may optionally include detecting, by the processing circuit 402, an uphill section 2 along the expected travel path 1. In response to determining that the charge level of the first electrical energy storage system 211a, 211b exceeds the charge level of the second electrical energy storage system 221a, 221b by at least a first threshold amount, the method may include controlling, by the processing circuit 402, the work machine 100 to assume a second orientation before entering the detected uphill section 2. In response to determining that the charge level of the second electrical energy storage system 221a, 221b exceeds the charge level of the first electrical energy storage system 211a, 211b by at least a first threshold amount, the method may include controlling, by the processing circuit 402, the work machine 100 to assume a first orientation before entering the detected uphill section 2.

[0069] The method may also optionally include detecting, by the processing circuit 402, a downhill section 3 along the expected travel path. In response to determining that the charge level of the first electrical energy storage system 211a, 211b exceeds the charge level of the second electrical energy storage system 221a, 221b by at least a second threshold amount, the method may include controlling, by the processing circuit 402, the work machine 100 to assume a second orientation before entering the downhill section 3. In response to determining that the charge level of the second electrical energy storage system 221a, 221b exceeds the charge level of the first electrical energy storage system 211a, 211b by at least a second threshold amount, the method may include controlling, by the processing circuit 402, the work machine 100 to assume a first orientation before entering the detected downhill section 3.

[0070] The method may further include evaluating, by the processing circuit 402, whether a first predetermined condition for allowing the work machine 100 to travel through the downhill section 3 in the second orientation is satisfied, wherein controlling the work machine 100 to take the second orientation is performed only when the first predetermined condition is satisfied.

[0071] Similarly, when an uphill section 2 along the expected driving path is detected, the method may also include the processing circuit 402 evaluating whether a second predetermined condition for allowing the work machine 100 to travel through the uphill section 2 in a first orientation is met, wherein the control of the work machine 100 to adopt the first orientation is only executed when the second predetermined condition is met.

[0072] Figure 5 4 is a schematic diagram of a computer system 400 for implementing the examples disclosed herein. The computer system 400 is suitable for executing instructions from a computer-readable medium to perform these and / or any functions or processes described herein. The computer system 400 may be connected (e.g., networked) to other machines in a LAN, an intranet, an extranet, or the Internet. Although only a single device is shown, the computer system 400 may include any device collection that executes an instruction set (or multiple instruction sets) individually or jointly to perform any one or more of the methods discussed herein. Therefore, any reference to a computer system, a computing system, a computer device, a computing device, a control system, a control unit, an electronic control unit (ECU), a processor device, a processing circuit, etc. in the present disclosure and / or claims includes a reference to one or more such devices to execute an instruction set (or multiple instruction sets) individually or jointly to perform any one or more of the methods discussed herein. For example, the control system may include a single control unit or multiple control units connected to each other or otherwise communicatively coupled, so that any executed function can be distributed between the control units as needed. In addition, such devices can communicate with each other or with other devices through various system architectures (such as directly or via a controller area network (CAN) bus, etc.).

[0073] Computer system 400 may include at least one computing device or electronic device that can include firmware, hardware and / or execute software instructions to implement the functions described herein. Computer system 400 may include processing circuit 402 (e.g., a processing circuit including one or more processor devices or control units), memory 404, and system bus 406. Computer system 400 may include at least one computing device with processing circuit 402. System bus 406 provides interfaces for system components including, but not limited to, memory 404 and processing circuit 402. Processing circuit 402 may include any number of hardware components for performing data or signal processing or for executing computer code stored in memory 404. Processing circuit 402 may include, for example, a general-purpose processor, a special-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA), a circuit containing a processing component, a group of distributed processing components, a group of distributed computers configured for processing, or other programmable logic devices designed to perform the functions described herein, discrete gate or transistor logic, discrete hardware components, or any combination thereof. Processing circuit 402 may also include computer executable code that controls the operation of a programmable device.

[0074] The system bus 406 can be any of several types of bus structures, which can be further interconnected to a memory bus (with or without a memory controller), a peripheral bus, and / or a local bus using any of a variety of bus architectures. The memory 404 can be one or more devices for storing data and / or computer code to complete or facilitate the methods described herein. The memory 404 can include a database component, an object code component, a script component, or other types of information structures for supporting various activities herein. Any distributed or local memory device can be utilized with the systems and methods of the present specification. The memory 404 can be communicatively connected to the processing circuit 402 (e.g., via a circuit or any other wired, wireless, or network connection) and can include computer code for performing one or more processes described herein. The memory 404 may include nonvolatile memory 408 (e.g., read-only memory (ROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), etc.) and volatile memory 410 (e.g., random access memory (RAM)), or any other medium that can be used to carry or store desired program code in the form of machine-executable instructions or data structures and that can be accessed by a computer or other machine having the processing circuit 402. A basic input / output system (BIOS) 412 may be stored in the nonvolatile memory 408 and may include the basic routines that help to transfer information between elements within the computer system 400.

[0075] The computer system 400 may also include or be coupled to non-transitory computer-readable storage media such as storage device 414, which may include, for example, an internal or external hard disk drive (HDD) (e.g., enhanced integrated drive electronics (EIDE) or serial advanced technology attachment (SATA)), a HDD for storage (e.g., EIDE or SATA), flash memory, etc. The storage device 414 and other drives associated with computer-readable and computer-usable media may provide non-volatile storage of data, data structures, computer-executable instructions, etc.

[0076] The hard-coded or soft-coded computer code may be provided in the form of one or more modules. The module may be implemented as software and / or hard-coded in the circuit to implement the functions described herein in whole or in part. These modules may be stored in a storage device 414 and / or a volatile memory 410 that may include an operating system 416 and / or one or more program modules 418. All or part of the examples disclosed herein may be implemented as a computer program 420 stored on a temporary or non-temporary computer-available or computer-readable storage medium (e.g., a single medium or multiple media) such as a storage device 414, which includes complex programming instructions (e.g., complex computer-readable program code) that cause the processing circuit 402 to perform the actions described herein. Therefore, the computer-readable program code of the computer program 420 may include software instructions for implementing the functions of the examples described herein when executed by the processing circuit 402. In some examples, storage device 414 may be a computer program product (e.g., a readable storage medium) having computer program 420 stored thereon, wherein at least a portion of computer program 420 may be loadable (e.g., loaded into a processor) for implementing the functionality of the examples described herein when executed by processing circuit 402. Processing circuit 402 may serve as a controller or control system of computer system 400 for implementing the functionality described herein.

[0077] The computer system 400 may include an input device interface 422 configured to receive input and selections to be transmitted to the computer system 400 when executing instructions, such as from a keyboard, mouse, touch-sensitive surface, etc. Such input devices may be connected to the processing circuit 402 through an input device interface 422 coupled to the system bus 406, but may be connected through other interfaces such as a parallel port, an Institute of Electrical and Electronics Engineers (IEEE) 1394 serial port, a universal serial bus (USB) port, an IR interface, etc. The computer system 400 may include an output device interface 424 configured to forward output to a display such as a display, a video display unit (e.g., a liquid crystal display (LCD) or a cathode ray tube (CRT)). The computer system 400 may include a communication interface 426 suitable for communicating with a network as appropriate or required.

[0078] The operational actions described in any of the exemplary aspects of this article are described to provide examples and discussions. The actions may be performed by hardware components, may be embodied in machine executable instructions to enable a processor to perform these actions, or may be performed by a combination of hardware and software. Although a specific order of method actions may be shown or described, the order of these actions may be different. In addition, two or more actions may be performed simultaneously or partially simultaneously.

[0079] In the following, possible features and feature combinations of the present disclosure are presented as a series of numbered examples.

[0080] Example 1. A computer system (400) comprising a processing circuit (402) configured to control an electric propulsion system (200) of an autonomous working machine (100), the autonomous working machine comprising a first axle (110) located near a first end (101) of the working machine (100) and a second axle (120) located near a second end (102) of the working machine (100), the electric propulsion system (200) comprising: - a first electric power system (210) configured to drive the first axle (110), the first electric power system (210) comprising a first electric energy storage system (211a, 211b) and a first electric motor (212), - a second electric power system (220) configured to drive the second axle (120), the second electric power system (220) comprising a second electric energy storage system (221a, 221b) and a second electric motor (222), The processing circuit (402) is configured to: - determining the longitudinal slope along the intended travel path (1) of the work machine (100), - determining the charge levels of the first electrical energy storage system and the second electrical energy storage system (211a, 211b, 221a, 221b), respectively, - controlling the working machine (100) to adopt a first orientation or a second orientation to travel along the expected travel path (1), the first end (101) of the working machine (100) being the front end in the first orientation, and the second end (102) of the working machine (100) being the front end in the second orientation, wherein the orientation of the working machine (100) is controlled according to the determined longitudinal slope and the determined power level.

[0081] Example 2. The computer system of Example 1, wherein the processing circuit (402) is further configured to: - detecting an uphill section (2) along the expected driving path (1), - in response to determining that the charge level of the first electrical energy storage system (211a, 211b) exceeds the charge level of the second electrical energy storage system (221a, 221b) by at least a first threshold amount, controlling the working machine (100) to assume the second orientation before entering the detected uphill section (2), and - In response to determining that the charge level of the second electrical energy storage system (221a, 221b) exceeds the charge level of the first electrical energy storage system (211a, 211b) by at least the first threshold amount, controlling the working machine (100) to assume the first orientation before entering the detected uphill section (2).

[0082] Example 3. The computer system of Example 2, wherein the uphill section (2) is a section whose vertical height (h) increases by at least a first threshold height (h1).

[0083] Example 4. The computer system of Example 3, wherein the first threshold height (h1) is set according to the weight of the work machine so that it decreases as the weight of the work machine increases.

[0084] Example 5. The computer system of any of the preceding examples, wherein the processing circuit (402) is configured to: - detecting a downhill section (3) along the expected driving path (1), - in response to determining that the charge level of the first electrical energy storage system (211a, 211b) exceeds the charge level of the second electrical energy storage system (221a, 221b) by at least a second threshold amount, controlling the working machine (100) to assume the second orientation before entering the detected downhill section (3), and - In response to determining that the charge level of the second electrical energy storage system (221a, 221b) exceeds the charge level of the first electrical energy storage system (211a, 211b) by at least the second threshold amount, controlling the working machine (100) to assume the first orientation before entering the detected downhill section (3).

[0085] Example 6. A computer system as described in Example 5, wherein the downhill section (3) is a section in which the vertical height (h) decreases by at least a second threshold height (h2), optionally wherein the second threshold height (h2) is set according to the weight of the work machine so that it decreases as the weight of the work machine increases.

[0086] Example 7. The computer system of Example 5 or 6, wherein the processing circuit (402) is further configured to: - evaluating whether a predetermined condition for allowing the working machine (100) to travel through the downhill section (3) in the second orientation is satisfied, The processing circuit (402) is configured to control the working machine (100) to adopt the second orientation only when the predetermined condition is met.

[0087] Example 8. The computer system of Example 7, wherein the predetermined condition is related to a weight of the work machine and / or to a longitudinal slope within the downhill section.

[0088] Example 9. A computer system as described in Example 7 or 8, wherein the predetermined condition is considered to be met when the longitudinal slope within the downhill section (3) is lower than a threshold slope, and / or when the longitudinal slope is not expected to cause the working machine to be tilted higher than a threshold slope, and / or when the working machine weight is lower than a threshold weight.

[0089] Example 10. An autonomous working machine (100) comprising or being communicatively connected to a computer system (400) as described in any one of Examples 1 to 9.

[0090] Example 11. A work machine as described in Example 10, wherein the work machine (100) includes a tiltable body (103) configured to carry a payload, and the tiltable body (103) is pivotable about a transverse axis located at the second end (102) of the work machine (100).

[0091] Example 12. A computer-implemented method for controlling an electric propulsion system (200) of an autonomous work machine (100), the autonomous work machine comprising a first axle (110) located near a first end (101) of the work machine (100) and a second axle (120) located near a second end (102) of the work machine (100), the electric propulsion system (200) comprising: - a first electric power system (210) configured to drive the first axle (110), the first electric power system (210) comprising a first electric energy storage system (211a, 211b) and a first electric motor (212), - a second electric power system (220) configured to drive the second axle (120), the second electric power system (220) comprising a second electric energy storage system (221a, 221b) and a second electric motor (222), The method comprises: - determining (S1) by a processing circuit (402) of a computer system (400) a longitudinal slope along an expected travel path (1) of the work machine (100), - determining (S2) by the processing circuit (402) the charge levels of the first energy storage system and the second energy storage system (211a, 211b, 221a, 221b), respectively, - The processing circuit (402) controls (S3) the working machine (100) to adopt a first orientation or a second orientation to travel along the expected travel path (1), the first end (101) of the working machine (100) being the front end in the first orientation, and the second end (102) of the working machine (100) being the front end in the second orientation, wherein the orientation of the working machine (100) is controlled according to the determined longitudinal slope and the determined power level.

[0092] Example 13. The method of Example 12, comprising: - detecting, by the processing circuit (402), an uphill section (2) along the expected driving path (1), - in response to determining that the charge level of the first electrical energy storage system (211a, 211b) exceeds the charge level of the second electrical energy storage system (221a, 221b) by at least a first threshold amount, controlling, by the processing circuit (402), the working machine (100) to assume the second orientation before entering the detected uphill section (2), and - In response to determining that the charge level of the second electrical energy storage system (221a, 221b) exceeds the charge level of the first electrical energy storage system (211a, 211b) by at least the first threshold amount, the processing circuit (402) controls the working machine (100) to assume the first orientation before entering the detected uphill section (2).

[0093] Example 14. The method of Example 13, wherein detecting the uphill road section (2) comprises detecting a road section whose vertical height (h) increases by at least a first threshold height (h1).

[0094] Example 15. The method of Example 14, wherein the first threshold height (h1) is set according to the weight of the work machine so that it decreases as the weight of the work machine increases.

[0095] Example 16. The method of any one of Examples 12 to 15, comprising: - detecting, by the processing circuit (402), a downhill section (3) along the expected travel path (1), - in response to determining that the charge level of the first electrical energy storage system (211a, 211b) exceeds the charge level of the second electrical energy storage system (221a, 221b) by at least a second threshold amount, controlling, by the processing circuit (402), the working machine (100) to assume the second orientation before entering the downhill section (3), and - In response to determining that the charge level of the second electrical energy storage system (221a, 221b) exceeds the charge level of the first electrical energy storage system (211a, 211b) by at least the second threshold amount, the processing circuit (402) controls the working machine (100) to assume the first orientation before entering the detected downhill section (3).

[0096] Example 17. The method of Example 16, wherein detecting the downhill road section (3) comprises detecting a road section whose vertical height (h) decreases by at least a second threshold height (h2).

[0097] Example 18. The method of Example 16 or 17, further comprising: - evaluating, by the processing circuit (402), whether a predetermined condition for allowing the working machine (100) to travel through the downhill section (3) in the second orientation is met, The working machine (100) is controlled to adopt the second orientation only when the predetermined condition is met.

[0098] Example 19. The method of Example 18, wherein the predetermined condition is related to the work machine payload and / or to the longitudinal slope within the downhill section (3).

[0099] Example 20. A method as described in Example 18 or 19, wherein the predetermined condition is deemed to be met when the longitudinal slope within the downhill section (3) is lower than a threshold slope, and / or when the longitudinal slope is not expected to cause the work machine to be tilted higher than a threshold slope, and / or when the work machine weight is lower than a threshold weight.

[0100] Example 21. A computer program product comprising program code for performing the method of any one of Examples 12 to 20 when executed by a processing circuit (402).

[0101] Example 22. A non-transitory computer-readable storage medium comprising instructions that, when executed by the processing circuit (402), cause the processing circuit to perform the method of any of Examples 12 to 20.

[0102] The terms used herein are only for the purpose of describing specific aspects and are not intended to limit the present disclosure. As used herein, the singular forms "a", "an" and "said" are intended to include the plural forms as well, unless the context clearly indicates otherwise. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items. It should also be understood that the terms "include" and / or "comprising" when used herein indicate the presence of stated features, integers, actions, steps, operations, elements and / or parts, but do not exclude the presence or addition of one or more other features, integers, actions, steps, operations, elements, parts and / or their groups.

[0103] It should be understood that although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another element. For example, without departing from the scope of the present disclosure, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element.

[0104] Relative terms such as "below" or "above" or "upper" or "lower" or "horizontal" or "vertical" may be used herein to describe the relationship of one element to another element as shown in the figures. It should be understood that these terms and those discussed above are intended to cover different device orientations in addition to the orientations depicted in the figures. It should be understood that when an element is referred to as being "connected" or "coupled" to another element, the element may be directly connected or coupled to the other element, or there may be intervening elements. In contrast, when an element is referred to as being "directly connected" or "directly coupled" to another element, there are no intervening elements.

[0105] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as those commonly understood by those of ordinary skill in the art to which the present disclosure belongs. It should also be understood that, unless otherwise clearly defined herein, the terms used herein should be interpreted as meanings consistent with their meanings in the context of this specification and the relevant art, and should not be interpreted in an idealized or overly formal sense.

[0106] It should be understood that the present disclosure is not limited to the aspects described above and shown in the accompanying drawings; rather, the skilled person will recognize that many changes and modifications may be made within the scope of the present disclosure and the appended claims. In the drawings and description, various aspects have been disclosed for illustrative purposes only and not for limiting purposes, and the scope of the present disclosure is set forth in the appended claims.

Claims

1. A computer system (400) comprising a processing circuit (402) configured to control an electric propulsion system (200) of an autonomous working machine (100), the autonomous working machine comprising a first axle (110) located near a first end (101) of the working machine (100) and a second axle (120) located near a second end (102) of the working machine (100), the electric propulsion system (200) comprising: - a first electric power system (210) configured to drive the first axle (110), the first electric power system (210) comprising a first electric energy storage system (211a, 211b) and a first electric motor (212), - a second electric power system (220) configured to drive the second axle (120), the second electric power system (220) comprising a second electric energy storage system (221a, 221b) and a second electric motor (222), The processing circuit (402) is configured to: - determining the longitudinal slope along the intended travel path (1) of the work machine (100), - determining the charge levels of the first electrical energy storage system and the second electrical energy storage system (211a, 211b, 221a, 221b), respectively, - controlling the working machine (100) to adopt a first orientation or a second orientation to travel along the expected travel path (1), the first end (101) of the working machine (100) being the front end in the first orientation, and the second end (102) of the working machine (100) being the front end in the second orientation, wherein the orientation of the working machine (100) is controlled according to the determined longitudinal slope and the determined power level.

2. The computer system of claim 1, wherein the processing circuit (402) is further configured to: - detecting an uphill section (2) along the expected driving path (1), - in response to determining that the charge level of the first electrical energy storage system (211a, 211b) exceeds the charge level of the second electrical energy storage system (221a, 221b) by at least a first threshold amount, controlling the working machine (100) to assume the second orientation before entering the detected uphill section (2), and - In response to determining that the charge level of the second electrical energy storage system (221a, 221b) exceeds the charge level of the first electrical energy storage system (211a, 211b) by at least the first threshold amount, controlling the working machine (100) to assume the first orientation before entering the detected uphill section (2).

3. The computer system of claim 2, wherein the uphill section (2) is a section whose vertical height (h) increases by at least a first threshold height (h1).

4. The computer system of claim 3, wherein the first threshold height (h1) is set according to the weight of the work machine so that it decreases as the weight of the work machine increases.

5. The computer system of any one of the preceding claims, wherein the processing circuit (402) is configured to: - detecting a downhill section (3) along the expected travel path (1), - in response to determining that the charge level of the first electrical energy storage system (211a, 211b) exceeds the charge level of the second electrical energy storage system (221a, 221b) by at least a second threshold amount, controlling the working machine (100) to assume the second orientation before entering the detected downhill section (3), and - In response to determining that the charge level of the second electrical energy storage system (221a, 221b) exceeds the charge level of the first electrical energy storage system (211a, 211b) by at least the second threshold amount, controlling the working machine (100) to assume the first orientation before entering the detected downhill section (3).

6. A computer system as described in claim 5, wherein the downhill section (3) is a section where the vertical height (h) decreases by at least a second threshold height (h2), and optionally, wherein the second threshold height (h2) is set according to the weight of the working machine so that it decreases as the weight of the working machine increases.

7. The computer system of claim 5 or 6, wherein the processing circuit (402) is further configured to: - evaluating whether a predetermined condition for allowing the working machine (100) to travel through the downhill section (3) in the second orientation is satisfied, The processing circuit (402) is configured to control the working machine (100) to adopt the second orientation only when the predetermined condition is met.

8. The computer system of claim 7, wherein the predetermined condition is related to a weight of the work machine and / or to a longitudinal gradient within the downhill section.

9. A computer system as described in claim 7 or 8, wherein the predetermined condition is considered to be met when the longitudinal slope within the downhill section (3) is lower than a threshold slope, and / or when the longitudinal slope is not expected to cause the working machine to be inclinated higher than a threshold inclination, and / or when the working machine weight is lower than a threshold weight.

10. An autonomous working machine (100) comprising or being communicatively connected to the computer system (400) according to any one of claims 1 to 9.

11. A work machine as described in claim 10, wherein the work machine (100) includes a tiltable body (103) configured to carry a payload, and the tiltable body (103) is capable of pivoting around a transverse axis located at the second end (102) of the work machine (100).

12. A computer-implemented method for controlling an electric propulsion system (200) of an autonomous working machine (100), the autonomous working machine comprising a first axle (110) located near a first end (101) of the working machine (100) and a second axle (120) located near a second end (102) of the working machine (100), the electric propulsion system (200) comprising: - a first electric power system (210) configured to drive the first axle (110), the first electric power system (210) comprising a first electric energy storage system (211a, 211b) and a first electric motor (212), - a second electric power system (220) configured to drive the second axle (120), the second electric power system (220) comprising a second electric energy storage system (221a, 221b) and a second electric motor (222), The method comprises: - determining (S1) by a processing circuit (402) of a computer system (400) a longitudinal slope along an expected travel path (1) of the work machine (100), - determining (S2) by the processing circuit (402) the charge levels of the first energy storage system and the second energy storage system (211a, 211b, 221a, 221b), respectively, - The processing circuit (402) controls (S3) the working machine (100) to adopt a first orientation or a second orientation to travel along the expected travel path (1), the first end (101) of the working machine (100) being the front end in the first orientation, and the second end (102) of the working machine (100) being the front end in the second orientation, wherein the orientation of the working machine (100) is controlled according to the determined longitudinal slope and the determined power level.

13. The method of claim 12, comprising: - detecting, by the processing circuit (402), an uphill section (2) along the expected driving path (1), - in response to determining that the charge level of the first electrical energy storage system (211a, 211b) exceeds the charge level of the second electrical energy storage system (221a, 221b) by at least a first threshold amount, controlling, by the processing circuit (402), the working machine (100) to assume the second orientation before entering the detected uphill section (2), and - In response to determining that the charge level of the second electrical energy storage system (221a, 221b) exceeds the charge level of the first electrical energy storage system (211a, 211b) by at least the first threshold amount, the processing circuit (402) controls the working machine (100) to assume the first orientation before entering the detected uphill section (2).

14. A computer program product comprising program code for performing the method of any one of claims 12 to 13 when executed by a processing circuit (402).

15. A non-transitory computer-readable storage medium comprising instructions which, when executed by the processing circuit (402), cause the processing circuit to perform the method of any one of claims 12 to 13.

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