Patent Description:
In connection with transportation of e.g. loads at a worksite, e.g. a construction site or a quarry, working machines in the form of haulers, excavators, wheel loaders, trucks or dumpers are frequently used. In its simplest configuration, the working machines are arranged to receive a load in a container or the like arranged on the vehicle, at a loading location or loading position of the worksite and drive, or otherwise move, to an unloading position or unloading location of the worksite, where it unloads the carried load. At the unloading location/position, the loads are taken care of. For example, at a quarry, large stone material transported to the unloading location/position are subject to a crusher.

Efficient use of energy of the working machines is desirable to reduce costs and environmental impact. Moreover, autonomous operation of the worksite, or at least the working machines operating at the worksite may contribute to an efficient work at the worksite, and may further reduce unnecessary costs. However, a worksite may be relatively complex, with multiple options for choosing the trajectory of the work sequence of the autonomous working machine. For example, the trajectory may be varied by varying the path between the loading and unloading locations/positions and/or by varying the speed over the travelled path. It is thus very time consuming to manually find out the best trajectory, and to program the autonomous working machine to operate accordingly. Moreover, choosing the best trajectory may change over time as the worksite evolves, further complicating the process.

<CIT>, <CIT> and <CIT> all relate to methods for controlling the operation of a vehicle and estimating the energy usage of the vehicle during such operation.

Thus, there is a need in the industry for an improved control of autonomous vehicles at the worksite.

An object of the invention is to provide a method for controlling an autonomous vehicle in a worksite, which method compares the energy usage over a test trajectory and a predetermined trajectory.

According to a first aspect of the invention, there is provided a method for controlling an autonomous vehicle in a worksite. The method comprises the steps of:.

Hereby, energy usage of the autonomous vehicle can be improved. Moreover, by determining whether or not the compared energy usage achieves a pre-set criteria, sub-optimization of the autonomous vehicle can effectively be avoided. For example, if the compared energy usage alone indicates that the test trajectory is beneficial over the predetermined trajectory, but the elapsed time of the work sequence for the test trajectory greatly exceeds the elapsed time of the work sequence for the predetermined trajectory, an action comparing the gain of the energy usage with the loss in elapsed time of the work sequence should be carried out to avoid undesired changes of the set trajectory. This is achieved by that the compared energy usage achieves a pre-set criteria.

According to at least one example embodiment, the predetermined trajectory is pre-set, indicating that the work sequence of the autonomous vehicle is known beforehand. The predetermined trajectory is thus typically the set trajectory including at least the set path and set speed of the work sequence prior to performing the method of the invention.

According to at least one example embodiment, the pre-defined variation is a variation of known character to at least the set path. The pre-defined variation may e.g. be a pre-defined change in the set path, such as e.g. an intended change in at least a portion of the set path. Thus, the pre-defined variation is a variation or change is an intended change or known character, different to e.g. a variation or change caused of external factors such as encountering and possibly recording of an unknown or unacquainted obstacle along the path of the autonomous vehicle. The pre-defined variation may be determined by simulations, e.g. by using the known set path and using topographical/map info to add a variation in set path.

According to at least one example embodiment, the test trajectory comprises the set path and set speed (i.e. the path and speed settings) of the predetermined trajectory with the exception of the pre-defined variation. In other words, the test trajectory comprises a test path and a test speed, wherein at least one of the test path and test speed is different to the set path and set speed of the predetermined trajectory.

According to at least one example embodiment, the energy usage of the work sequence corresponding to the predetermined trajectory typically is known, or it is determined/estimated during the performance of such work sequence. Correspondingly, the energy usage of the work sequence corresponding to the test trajectory may be determined/estimated during the performance of such work sequence. However, according to at least one example embodiment, the energy usage of the work sequence of at least one of the predetermined trajectory and test trajectory is simulated. For example, the energy usage of the test trajectory may be simulated by using known energy usage related to the predetermined trajectory, and estimated energy usage related to the pre-defined variation, e.g. by using topographical/map info or other information of the terrain.

It should be understood that if the compared energy usage does not achieve the pre-set criteria, the predetermined trajectory is typically kept as the set trajectory.

According to at least one example embodiment, the pre-set criteria is at least that the test trajectory has lower energy usage than the predetermined trajectory.

Hereby, the determination of whether the test trajectory is to be set as the new set trajectory is simplified. Thus, according to such embodiments, the method will not result in new set trajectory which has a higher energy usage compared to the predetermined trajectory.

By the first aspect of the invention, the determination of whether the test trajectory is to be set as the new set trajectory can be based on desired characteristics or set limits of the working sequence. For example, a maximum elapsed time of the work sequence or set path may be used to not change the new set trajectory to the test trajectory even if the energy usage of the test trajectory is improved compared to the predetermined trajectory. According to another example embodiment, the test trajectory is set as new set trajectory based on a relation of the gain in energy usage and penalty of the elapsed time of the work sequence or set path. Corresponding relations can be made additionality or alternatively between the energy usage and the minimum average speed, maximum allowed vibration and desired battery usage.

According to at least one example embodiment, the method comprises performing a plurality of test trajectories, and comparing the energy usage between the predetermined trajectory and each test trajectory, and subsequently moving forward with the most promising test trajectory. The most promising test trajectory e.g. being related to the lowest energy consumption. Hereby, a local minimum may be avoided.

According to the invention, the pre-defined variation includes noise.

Such noise is advantageous to use as pre-defined variation as the resulting test trajectory easily can be compared and evaluated based on the variation.

According to at least one example embodiment, the noise comprises a random signal of a known size and characteristics, set in relation to how much it is allowed to be varied. For example, the noise is a colored noise or a pseudo random signal with a chosen bandwidth.

According to at least one example embodiment, the autonomous vehicle further comprises an auxiliary equipment configured to perform work such as digging or loading, and wherein the predetermined trajectory comprises the action of performing work of the autonomous vehicle.

Hereby, the energy usage of any auxiliary equipment may be included in the compared energy usage.

According to at least one example embodiment, the trajectory of the work sequence corresponds to the trajectory of the auxiliary equipment of the autonomous vehicle, such as e.g. a tool being e.g. the boom and bucket of an excavator, or drilling tool of a driller, and/or the trajectory of the work sequence corresponds to the trajectory of autonomous vehicle itself, i.e. the path along which the autonomous vehicle propels. Both these types of trajectories are related to energy usages. For the trajectory of the auxiliary equipment of the autonomous vehicle, energy is used during the association action of the auxiliary equipment, and as the auxiliary equipment is moved. The auxiliary equipment may e.g. be moved from a starting position to a target position, or an action position in which a tool of the auxiliary equipment performs the associated action, and possibly further moved to a final position (which e.g. may be the same as the starting position). Such movement of the auxiliary equipment and performing of the association action is an example of a work sequence of the autonomous vehicle. For the trajectory of the autonomous vehicle itself, energy is used for propelling the autonomous vehicle, and energy is additionally used for any action performed during the propelling of the autonomous vehicle, e.g. loading, dumping and/or carrying a load in case the autonomous vehicle is a dumper or hauler. The autonomous vehicle may e.g. be moved from a starting location to a target location, or an action location in which a tool of the auxiliary equipment performs the associated action, and possibly further moved to a final location (which e.g. may be the same as the starting location). Such movement of the autonomous vehicle, and potentially any action performed during the movement, is another example of a work sequence of the autonomous vehicle.

Thus, and according to at least one example embodiment, the trajectory generally includes a path along which the auxiliary equipment and/or autonomous vehicle moves, and the speed of the auxiliary equipment and/or autonomous vehicle along the path, respectively.

According to at least one example embodiment, the pre-defined variation is a variation in at least the action of performing work, or the path position of the action of performing work.

Hereby, the energy usage in relation to performing work may be improved, in correspondence with the pre-set criteria.

According to at least one example embodiment, the autonomous vehicle is configured for carrying a load, and wherein the pre-defined variation includes at least a variation of the set path by the load carrying distance of the autonomous vehicle.

Hereby, the energy usage in relation to portion of the set path which is subject to carrying a load may be improved, in correspondence with the pre-set criteria. For example, the action location may be a location in which the autonomous vehicle receives a load, and the target location a location in which the load is dumped. The pre-defined variation may thus be a variation in set path between the action location and the target location.

According to at least one example embodiment, the set path corresponds to a travel distance of the autonomous vehicle from a starting location to a target location, and/or corresponds to a travel distance of an auxiliary equipment of the autonomous vehicle from a starting position to a target position.

Hereby, the set path can be readily defined and compared between the determined trajectory and the test trajectory, e.g. related to energy usage and elapsed time of the work sequence or other desired parameter.

According to at least one example embodiment, the predetermined trajectory comprises a set path having a starting location and a target location and/or a starting position and a target position, and wherein the test trajectory comprises a set path having the same starting location and target location and/or the same starting position and target position, respectively.

Thus, the pre-determined variation is at least a variation in set path somewhere between the staring location/position and target location/position. Hereby, the compared energy usage can be carried out for the autonomous vehicle performing the same or similar tasks, or at least starting from the same location or position, and ending in the same location or position. Thus, the pre-defined variation is bounded or limited, so as to not affect the movement of the autonomous vehicle in an undesired manner.

According to at least one example embodiment, the pre-defined variation includes a variation in set path of a pre-defined path-portion between the starting location and target location or between the starting position and target position.

Such pre-defined path-portion may correspond to a portion of the set path with known high energy usage, or known cumbersome terrain. By directing the pre-defined variation to such pre-defined path-portion, various test trajectories can be performed with a targeted effort to improve the performance at this specific path-portion.

According to at least one example embodiment, the set path of the predetermined trajectory is a first path, and the set path of the test trajectory is a second path, wherein the second path is different to the first path.

Hereby, the compared energy usage can be carried out for the autonomous vehicle for two different paths or routes. The second path may be only partly different to the first path as previously stated, or the second path may be wholly different to the first path. According to at least one example embodiment, the first path and the second path share the same starting location/position and/or the same target location/position, but nothing beyond that. Stated differently, the first path and the second path only overlap at the starting location/position and/or the target location/position. According to at least one example embodiment, the first path does not overlap with the second path.

According to at least one example embodiment, the second path is shorter compared to the first path.

A shorter path typically results in a lower energy usage and/or a lower elapsed time of the work sequence or set path.

According to at least one example embodiment, the pre-defined variation includes at variation in set path based on more favorable road conditions, such as e.g. a more favorable terrain.

According to at least one example embodiment, the autonomous vehicle comprises a memory, and wherein the memory is configured to store historical data relating to a travelled path of the autonomous vehicle having a travelled speed, as a predetermined trajectory.

That is, the predetermined trajectory is a historically performed trajectory, with the set path being the travelled path and the set speed being the travelled speed. The historical data may furthermore comprise the historical energy usage of the predetermined trajectory.

According to at least one example embodiment, the autonomous vehicle comprises a motor and a battery configured to supply energy to the motor, and wherein the method further comprises measuring the energy usage of the battery for the predetermined trajectory and the test trajectory.

Hereby, the energy usage can be readily defined and compared between the determined trajectory and the test trajectory.

Additionality or alternatively, the battery furthermore energizes any auxiliary equipment of the autonomous vehicle, preferably by a power take off arrangement. According to at least one example embodiment, the battery comprises a plurality of battery units, wherein at least one battery is configured to energize the motor, and at least one battery is configured to energize the auxiliary equipment.

According to at least one example embodiment, the autonomous vehicle is a working machine.

The working machine may e.g. be an autonomous dumper, hauler or excavator. The working machine may be a driller or crusher.

According to at least one example embodiment, the predetermined trajectory comprises an uphill path-portion, and the pre-defined variation includes a variation in the set path to avoid the uphill path-portion, or a variation in the set speed prior to, or during, the uphill path-portion.

Hereby, the compared energy usage can be carried out for the autonomous vehicle for different ways to manage the uphill path-portion. Uphill is a typically path portion associated with increased energy usage. For example, the set speed of the autonomous vehicle may be set higher prior to the uphill path-portion in order to carry on a higher inertia into the uphill path-portion.

According to at least one example embodiment, the pre-defined variation is bounded by safety parameters and vehicle limitations.

Hereby, the inclusion of the pre-defined variation will not risk causing the autonomous vehicle to be operated outside of such safety parameters or vehicle limitations.

According to a second aspect of the present invention a computer program is provided. The computer program comprising program code means for performing the steps of the first aspect of the invention, when the program is run on a computer.

According to a third aspect of the present invention a computer readable medium carrying a computer program is provided. The computer readable medium carrying a computer program comprising program code means for performing the steps of the first aspect of the invention, when the program is run on a computer.

Effects and features of the second and third aspects of the invention are largely analogous to those described above in connection with the first aspect of the invention.

According to a fourth aspect of the present invention, an autonomous vehicle, such as autonomous working machine, is provided. The autonomous vehicle comprises a computer program according to the second aspect of the invention, or a computer readable medium carrying a computer program according to the third aspect of the invention.

The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which exemplary embodiments of the invention are shown. The invention may, however, be embodied in many different forms and should not be construed as limited to the embodiment set forth herein; rather, these embodiments are provided for thoroughness and completeness. In the present detailed description, various embodiments of the method according to the present invention are mainly discussed with reference to a hauler carrying a load from a loading location to an unloading location at a worksite, and an excavator digging at a desired spot and moving the dug load to another position. It should be noted that this by no means limits the scope of the present invention which is equally applicable to a wide range of different autonomous vehicles, specifically working machines, operating between a staring location or starting position and target location or target position, respectively.

In <FIG> and <FIG> embodiments of the present invention are described with reference to the operation and control of an autonomous vehicle in a worksite. In <FIG> the autonomous vehicle is a working machine exemplified as a hauler and in <FIG> the autonomous vehicle is a working machine exemplified as an excavator. In <FIG>, a method for controlling an autonomous vehicle in a worksite is described with reference to a flow chart.

<FIG> is a perspective view of a worksite in the form of a quarry, in which a hauler <NUM> is operating. The number of haulers or other autonomous vehicles operating at the worksite is exemplifying. It should be realized that there may be more haulers or other autonomous vehicles operating at the worksite. At least some of the haulers or other autonomous vehicles may be members of a common collaborative group, i.e. a group of autonomous vehicles collaborating in performing a specific task.

The hauler <NUM> in <FIG> is controlled to operate according to a predetermined trajectory including at least a set path <NUM> and a set speed. The set speed may vary along the set path <NUM>. The hauler <NUM> is typically equipped with hardware and software resources <NUM>, e.g. a memory, comprising the predetermined trajectory, or means for receiving instructions of operating according to the predetermined trajectory. For example, the memory may be configured to store historical data relating to a travelled path with associated travelled speed, here represented by the set path <NUM> as it is assumed that the hauler <NUM> at least once have been operated according to the predetermined trajectory, while recording and storing data on the memory. The hauler <NUM> further comprises a motor, such as an electric motor, for at least propelling the hauler <NUM>, and at least one battery configured to supply energy to the motor. Moreover, the hauler <NUM> comprises auxiliary equipment configured to perform work, here in the form of a container <NUM> for carrying a load <NUM>, and means for operating the container <NUM>, typically tilting cylinders for tilting the container <NUM> in order to dump or discharge the load <NUM>. The auxiliary equipment is preferably energised by the at least one battery. The hardware and software resources <NUM> of the hauler <NUM> may furthermore be configured to measure the energy usage of the battery as the hauler <NUM> operates (i.e. propels and/or performs work) in the worksite.

The set path <NUM> in <FIG> extends from a starting location <NUM>, in which the hauler <NUM> may be stationed when being charged at a charging station <NUM>, to a first target location <NUM> being a loading location <NUM> in which the hauler <NUM> receives a load <NUM> from a feeding crusher <NUM>, further to a second target location <NUM> being an unloading location in which the hauler <NUM> unloads or discharges the load <NUM> at an unloading site <NUM>, and a final location <NUM>, here being the same as the starting location <NUM> where the hauler <NUM> may be stationed and/or charged. In the particular example in <FIG>, the hauler <NUM> may initially begin at the starting location <NUM>, and then directly move to the loading location <NUM> without passing the unloading location <NUM>. After having received a load <NUM> at the loading location <NUM>, the hauler typically operates between the loading location <NUM> and the unloading location <NUM>, until further charging is needed, or another type of change in path is desired or need. Thus, the hauler <NUM> operates according to a work sequence, following the predetermined trajectory and the set path <NUM>, here being the travelled distance from the staring location <NUM> to the final location <NUM>. In the specific example of <FIG>, the work sequence is a work cycle. It should be noted that during the work sequence, the hauler <NUM> needs not to stop at the starting location <NUM> or the final location <NUM>, but may operate between the two target locations <NUM>, <NUM> in order to repeatedly receiving a load and discharging the load as previously mentioned. Alternatively, the set path <NUM> of the predetermined trajectory neglects the charging station <NUM>, and sets the first target location <NUM> at the feeding crusher <NUM> as "starting location" and the second target location <NUM> at the unloading site <NUM> as "target location". In such embodiments, the set path may include a final location being the same as the staring location in order to operate the hauler <NUM> in a work cycle. According to at least one example embodiment, the hauler <NUM> comprises several predetermined trajectories of different working sequences, e.g. one related to charging the hauler <NUM>, and one related to operating the hauler <NUM> between the feeding crusher <NUM> and the unloading site <NUM>.

Thus, in the specific example of <FIG>, the predetermined trajectory of the hauler <NUM> comprises the set path <NUM> by which the hauler <NUM> is propelled, and comprises the action of performing work, e.g. carrying a load between the first target location <NUM> and the second target location <NUM>, as well as tilting the container <NUM> for discharging the load <NUM> at the second target location <NUM>.

According to the method of the invention, the predetermined trajectory is subject to an added pre-defined variation to form a test trajectory, which is further described with reference to <FIG>. The pre-defined variation may e.g. include a variation in set path <NUM> or set speed over at least a portion of the set path <NUM>, compared to the predetermined trajectory.

In <FIG>, the set path <NUM> of the test trajectory is indicated by a dashed line <NUM>, extending from the first target location <NUM> at the feeding crusher <NUM> to the second target location <NUM> at the unloading site <NUM>. Thus, <FIG> illustrates a first path <NUM> being the set path <NUM> of the predetermined trajectory, and a second path <NUM> being the set path <NUM> of the test trajectory. As shown in the example embodiment of <FIG>, the second path <NUM> is shorter than the first path <NUM>. In more detail, the second path <NUM> is arranged to avoid the uphill path-portion <NUM> of the first path <NUM>, and to in a more direct manner reach the unloading site <NUM> (the uphill portion <NUM> is indicated with a sloped surface in a partly perspective view in <FIG>). Hereby, energy usage of the working sequence of the test trajectory and the second path <NUM> may be decrease compared to operating the hauler <NUM> according to the predetermined trajectory, as a result of the relatively shorter path, and the avoidance of the uphill path-portion <NUM>. In the example of <FIG>, the pre-defined variation for forming the test trajectory also includes a variation in the action of performing work as the load carrying distance of the hauler <NUM> of the second path <NUM> is shorter compared to the load carrying distance of the hauler <NUM> of the first path <NUM>.

Moreover, the second path <NUM> is not drawn via the charging station <NUM>, and does not reach the same elevation as compared to the first path <NUM> (the high elevation of the first path <NUM> may e.g. facilitate discharge of the load at the unloading site <NUM>). However, to operate the hauler <NUM> along the second path <NUM> may still be beneficial, at least for a time until discharge of load at the unloading site <NUM> need to be carried out from an increased elevation (as provided by the first path <NUM>) or when the hauler <NUM> needs to be charge at the charging station <NUM>. According to another example embodiment, the pre-defined variation is a variation of the set speed, e.g. prior to the uphill path-portion <NUM>. In such example, the set path of the test trajectory will be the same as the set path <NUM> of the predetermined trajectory, but the trajectories will differ as the set speed of a least a portion of the set path <NUM> differ. The criteria for choosing to operate the hauler <NUM> according to the predetermined trajectory or the test trajectory is further described with reference to <FIG>.

<FIG> illustrates an example embodiment in which the autonomous vehicle <NUM> is at a standstill, but nevertheless is controlled according to the method of the invention. In <FIG>, the autonomous vehicle is an excavator <NUM> comprising auxiliary equipment <NUM> such as a bucket <NUM>, and a boom <NUM>. The excavator <NUM> may be correspondingly equipped with regards to carrying out the method of the invention as the hauler <NUM> in <FIG>. Thus, the excavator <NUM> may comprise hardware and software resources, such as e.g. a memory, and at least one battery and motor for propelling the excavator, as well as for energizing the action of performing work by the auxiliary equipment <NUM>.

The excavator <NUM> in <FIG> is controlled to be operated according to a predetermined trajectory including at least a set path <NUM> and a set speed. Compared to the set path <NUM> described with reference to <FIG>, the autonomous vehicle of <FIG> is not propelled along the set path <NUM>, but instead the set path <NUM> describes the distance travelled by moving the auxiliary equipment <NUM>, i.e. here the boom <NUM> and the bucket <NUM>.

The set path <NUM> in <FIG> extends from a starting position <NUM>, in which the auxiliary equipment <NUM> is arranged such that the bucket <NUM> may dig at a desired spot, to a target position <NUM>, in which the excavator <NUM> discharges or dumps the load of the bucket <NUM>. Subsequently, the auxiliary equipment <NUM> may be moved to a final position, e.g. by being returned to the starting position <NUM>. Thus, the excavator <NUM> operates according to a work sequence, following the predetermined trajectory and the set path <NUM>, here being the travelled distance from the staring position <NUM> to the target position <NUM>. Additionally, or alternately the work sequence of the excavator <NUM> includes propelling the excavator <NUM> from standstill (i.e. representing a starting location) to a target location. For example, the starting position <NUM> in which the bucket <NUM> dig at the desired spot may be located at the current standstill location, wherein the target position <NUM> in which the excavator <NUM> discharges or dumps the load of the bucket <NUM>, may be located at the target location. Thus, in the specific example of <FIG>, the predetermined trajectory of the excavator <NUM> comprises the set path <NUM> by which the auxiliary equipment <NUM> is moved, and may additionally comprise the movement of the excavator <NUM> itself as it is moved from standstill to a target location.

Corresponding to the hauler <NUM> in <FIG>, the predetermined trajectory of the excavator <NUM> is subject to an added pre-defined variation to form a test trajectory. The pre-defined variation may e.g. include a variation in set path <NUM> or set speed over at least a portion of the set path <NUM>, compared to the predetermined trajectory. The criteria for choosing to operate the excavator <NUM> according to the predetermined trajectory or the test trajectory is further described with reference to <FIG>.

<FIG> is a flow chart describing the steps in accordance with embodiments of the invention. The method described in <FIG> may be used in accordance with the hauler <NUM> of <FIG> and/or the excavator <NUM> of <FIG>. Preferably, at least some of the steps of the method is provided by a computer program, or computer readable medium carrying a computer program. The computer program comprising program code means for performing the steps of the method described with reference to <FIG>, when the program is run on a computer, e.g. a hardware resource of the autonomous vehicle.

In step <NUM> a predetermined trajectory of a work sequence of the autonomous vehicle is received. The predetermined trajectory includes at least a set path and a set speed. Example of such predetermined trajectories with work sequences are provided in <FIG> and <FIG>. Moreover, the predetermined trajectory may comprise the action of performing work of the auxiliary equipment of the autonomous vehicle.

In step <NUM>, a pre-defined variation is added to the predetermined trajectory to form a test trajectory. The pre-defined variation includes at least a variation in set path or set speed. As already described with reference to <FIG> and <FIG>, the pre-defined variation may additionally include a variation in the action of performing work of the auxiliary equipment, or the path position of the action of performing work, e.g. the load carrying distance of the hauler <NUM> of <FIG>. The pre-defined variation comprises or consists of noise in set path. Additionally or alternatively, the pre-defined variation is bounded by safety parameters and vehicle limitations.

In step <NUM>, the energy usage over the test trajectory and the predetermined trajectory is compared. Of course, the method may include implicit steps as determining the energy usage of the predetermined trajectory and/or the test trajectory, e.g. by calculating energy usage of the at least one battery of the autonomous vehicle.

In step <NUM>, it is determined whether or not the compared energy usage achieves a pre-set criteria. The pre-set criteria may e.g. be at least that the test trajectory has lower energy usage than the predetermined trajectory. The pre-set criteria relate the compared energy usage with the elapsed time of the work sequence, elapsed time of the set path, maximum allowed vibration, and/or desired battery usage.

In step <NUM>, the test trajectory is set as a new set trajectory of the autonomous vehicle in response to determining that the compared energy usage achieves the pre-set criteria. If it is determined that the compared energy usage does not achieve the pre-set criteria, the predetermined trajectory is kept, or a new test trajectory is performed (according to step <NUM>) with the subsequent steps.

It should be understood that the autonomous vehicle is typically equipped with hardware and software resources known to the skilled person, e.g. associated hardware resources such as e.g. processing units being provided in the form of one or more processors together with process software including computer program memory including computer program code for performing the method of the invention.

Claim 1:
A method for controlling an autonomous vehicle (<NUM>, <NUM>) in a worksite, the method comprising the steps of:
- receiving (<NUM>) a predetermined trajectory of a work sequence of the autonomous vehicle, the predetermined trajectory including at least a set path (<NUM>, <NUM>) and a set speed,
- adding (<NUM>) a pre-defined variation to the predetermined trajectory to form a test trajectory (<NUM>), the variation including at least a variation in set path,
- comparing (<NUM>) the energy usage over the test trajectory and the predetermined trajectory,
- determining (<NUM>) whether or not the compared energy usage achieves a pre-set criteria,
- setting (<NUM>) the test trajectory as a new set trajectory of the autonomous vehicle in response to determining that the compared energy usage achieves the pre-set criteria, wherein the pre-set criteria is at least that the compared energy usage is related to one of the following: elapsed time of the work sequence, elapsed time of the set path, maximum allowed vibration, desired battery usage, wherein the pre-defined variation in set path includes noise.