EP4727817A1

EP4727817A1 - Fault tolerant actuator coordination in heavy-duty vehicles

Info

Publication number: EP4727817A1
Application number: EP23733339.8A
Authority: EP
Inventors: Esteban GELSO; Mats Jonasson; Adithya ARIKERE; Mats RYDSTRÖM
Original assignee: Volvo Truck Corp
Current assignee: Volvo Truck Corp
Priority date: 2023-06-19
Filing date: 2023-06-19
Publication date: 2026-04-22
Also published as: WO2024260537A1

Abstract

A computer-implemented control system (200, 400, 700) for vehicle motion management, VMM, of a heavy-duty vehicle (100), where the vehicle (100) comprises a plurality of motion support devices, MSD, (230) and where each MSD is arranged to control at least one actuator (530, 540, 550) of the vehicle (100) based on a motion request (225, 431, 432, 433) received from the computer-implemented control system (200, 400, 700), the control system (200, 400, 700) being arranged to obtain a desired total impact (210, 460) on the motion of the vehicle (100) by the plurality of MSDs, the control system (200, 400, 700) comprising an MSD coordination function (220, 470) configured to allocate motion requests (225, 431, 432, 433) to the MSDs such that the desired total impact (210, 460) on the motion of the vehicle (100) is obtained, based on a cost function, and on respective actuator capabilities associated with the MSDs, the control system (200, 400, 700) further comprising a fault detection function (270, 480) arranged to identify one or more faulty MSDs in the plurality of MSDs, where the control system (200, 400, 700) is arranged to adapt the cost function and/or the actuator capabilities associated with the one or more faulty MSDs in response to detecting fault by the fault detection function (270, 480).

Description

FAULT TOLERANT ACTUATOR COORDINATION IN HEAVY-DUTY VEHICLES

TECHNICAL FIELD

This disclosure relates generally to control of heavy-duty vehicles such as trucks, buses, and construction equipment. In particular aspects, the disclosure relates to systems and methods for coordinating a plurality of actuators on a heavy-duty vehicle to obtain a desired motion by the vehicle. Although the disclosure may be described with respect to a particular vehicle, the disclosure is not restricted to any particular vehicle or vehicle type.

BACKGROUND

A heavy-duty vehicle, such as a truck or a bus, may experience various faults and actuator malfunctions during use, such as tyre explosions, friction brake fading, and malfunction in the steering system of the vehicle. It is desired that these faults and malfunctions are handled in a safe manner and with limited impact on the overall motion behavior of the vehicle.

SUMMARY

The present disclosure relates generally to control systems and methods for fault tolerant actuator coordination in heavy-duty vehicles. Some of the techniques disclosed herein may be described in terms of a computer system and/or as methods performed by the computer system.

There is disclosed a computer-implemented control system for vehicle motion management (VMM) of a heavy-duty vehicle. The vehicle comprises a plurality of motion support devices (MSD), where each MSD is arranged to control at least one actuator of the vehicle, such as a brake, propulsion unit, steering actuator, and so on, based on a motion request received from the computer-implemented control system. The control system is arranged to obtain a desired total impact on the motion of the vehicle by the plurality of MSDs, i.e., information related to a desired change in the motion by the vehicle to be generated by the different actuators working together, such as a desired global force vector acting on the vehicle to change its motion behavior. The control system comprises an MSD coordination function configured to allocate motion requests to the MSDs such that the desired total impact on the motion of the vehicle is obtained, based on a cost function, and on respective actuator capabilities associated with the MSDs. The control system further comprises a fault detection function arranged to identify one or more faulty MSDs in the plurality of MSDs. The control system is arranged to adapt the cost function and/or the actuator capabilities associated with the one or more faulty MSDs in response to detecting fault by the fault detection function. Thus, if one or more MSDs fail or for some reason starts to perform worse than normal, the MSD coordinator function automatically reallocates requests to other MSDs in order to mitigate consequences of the MSD failure. The impact on the overall vehicle motion control is thus reduced. For instance, if the steering suddenly looses some or all function, the MSD coordinator function can re-allocate motion requests such that vehicle steering is instead handled by the brakes on the vehicle. It is a further advantage that the re-allocation can be performed based on a cost function, such that the new allocation is also efficient in terms of some predetermined efficiency metric. The MSD coordination function may be configured to solve a constrained optimization problem, where the constraints are determined based on MSD capabilities. This way the MSD allocation can be optimized, and the cost functions used in the optimization solver can also be adjusted to obtain a desired effect, such as reduced energy consumption, reduced component wear, increased passenger comfort, and so on. The MSD coordination function is optionally configured to solve an optimization problem associated with one or more cost functions, where the cost functions are configured in dependence of any of; an energy expenditure of MSD actuators, a wear incurred on MSD actuators, and a passenger convenience metric.

According to some aspects the control system comprises a motion model function arranged to adapt at least one cost function associated with actuation by an MSD based on input from the fault detection function. This way a detected fault immediately results in a change in the cost function, which then has an effect on the control solution determined by the MSD coordination function. The control system may also comprise a motion model function arranged to adapt a control effectiveness matrix associated with actuation by the plurality of MSDs based on input from the fault detection function.

According to some aspects, the control system comprises an MSD capabilities function arranged to adapt MSD constraints of the control system based on input from the fault detection function. A fault in one or more MSDs often results in a reduction in MSD capabilities. An exploded tyre for instance significantly impacts the ability by the wheel to generate wheel force. By connecting the fault detection function to the MSD capabilities function, which then provides capability information to the MSD coordination function, an impact of a fault is quickly and reliably accounted for in the MSD coordination. An axle/wheel capabilities function can be arranged to adapt axle capabilities and/or wheel capabilities based on input from fault detection function in a similar manner.

According to some aspects, the fault detection function is configured to identify a faulty MSD in terms of type and location, and to transmit the type and location of the faulty MSD as an output of the fault detection function. This information allows for a more refined adjustment of, e.g., MSD capability information. It is particularly beneficial that the system detects the location of the faulty MSD, since this allows the system to better predict the impact of the fault and thus better mitigate the consequences by MSD motion request re-allocation. The fault detection function can also be configured to quantify a magnitude of a failure in a faulty MSD, and to transmit the magnitude of the failure as an output of the fault detection function. This allows the system to better determine the impact of the fault, since some failures may be small magnitude and other failures may be large magnitude, for the same MSD. A friction brake may, e.g., suffer from reduced performance due to high temperature, and total brake-down in case of total brake fading.

The fault detection function may be arranged to detect any of an explosion of a tyre of the vehicle, malfunction in a power steering system of the vehicle, malfunction in a service brake of the vehicle, malfunction in a communication bus of the vehicle, and malfunction in an actuator supply line of the vehicle, such as a pneumatic air line, a gas line, a hydraulic line or an electrical supply which malfunction results in reduced performance of the MSD. The fault detection function is preferably also arranged to detect actuator overheating in an actuator on the vehicle, and to quantify the effect of said overheating. This is an advantage since different MSDs react differently to increases in temperature (and some MSDs are also sensitive to too low temperatures).

The control system may be arranged to initially set an MSD capability of a faulty MSD to zero in response to detecting fault, and then gradually increase capability. This allows the system to probe the consequences of a failure in case such failures are not immediately apparent to the system.

The different techniques and features of the computer system discussed herein may also be described as corresponding methods, associated with the same advantages. The above aspects, accompanying claims, and/or examples disclosed herein above and later below may be suitably combined with each other as would be apparent to anyone of ordinary skill in the art.

Additional features and advantages are disclosed in the following description, claims, and drawings, and in part will be readily apparent therefrom to those skilled in the art or recognized by practicing the disclosure as described herein. There are also disclosed herein control units, computer systems, computer readable media, and computer program products associated with the above discussed technical benefits.

BRIEF DESCRIPTION OF THE DRAWINGS

With reference to the appended drawings, below follows a more detailed description of aspects of the disclosure cited as examples.

Figure 1 illustrates an example heavy-duty vehicle,

Figure 2 is a block diagram illustrating a motion support device coordination system,

Figures 3A-D illustrate various methods of actuator fault mitigation,

Figure 4 shows aspects of an example vehicle motion control system,

Figure 5 illustrates some example motion support devices on a heavy-duty vehicle,

Figures 6A-B are graphs illustrating fault detection based on sensor signal input,

Figure 7 is a schematic diagram of an exemplary computer system,

Figure 8 is a flow chart illustrating methods, and

Figure 9 shows an example computer program product.

DETAILED DESCRIPTION

The present disclosure will now be described more fully hereinafter with reference to the accompanying drawings, in which exemplary embodiments are shown. The disclosure may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided for thoroughness and completeness. Like reference character refer to like elements throughout the description. Aspects set forth below represent the necessary information to enable those skilled in the art to practice the disclosure. Figure 1 illustrates an example heavy-duty vehicle 100, here in the form of a truck comprising a tractor 110 and a trailer 120. The tractor 110 of the vehicle 100 comprises two front wheels 101 of a steered front axle and a set of rear wheels 102 on rear tractor axles. The trailer 120 also comprises wheels 103 that support it on the road surface 104. One or more tractor rear axles, and/or one or more trailers axles may also be steered axles.

A heavy-duty vehicle may be defined in some cases as a freight vehicle of more than 3.5 metric tons or as a passenger transport vehicles of more than 8 seats. A heavy-duty vehicle may also be defined as a vehicle with a frontal area that is larger than 45 square feet, which is about 4.18 square meters. The teachings herein are particularly suitable for use with semi-trailer type vehicles such as that shown in Figure 1 and rigid trucks, including rigid trucks with dollies and one or more trailers.

The vehicle 100 comprises a computer-implemented control system arranged to estimate vehicle motion relative to the road surface 104 and/or in a global reference system. The control system implements one or more control functions that control vehicle motion based at least in part on the estimated vehicle motion. This control system may comprise one or more control units 130 distributed over the vehicle or centralized at one place. Each vehicle control unit 130 may comprise one or more processor devices. A processor device may be distributed over several spatially separated units or centralized in one place. The control system, or parts thereof, may be arranged to communicate via wireless link 140 to a wireless access point 150, such as a radio base station of a cellular access network or the like. Thus, the vehicle control system may communicate with one or more remote servers 160 implementing data repositories, remote processing resources, and the like, in order to exchange data and perform various computation tasks. The vehicle control system 130 may be referred to as, or form part of, a system for vehicle motion management (VMM).

Generally, herein, various forms of data signals and messages are transmitted between functions, internal to some processing circuitry or in between physically separated processing devices. These signals and messages are often referred to in terms of data indicative of a given parameter or data item. It is appreciated that the term “data indicative of’ is to be construed broadly to mean, e.g., the actual value, an approximation of the value, or an abstraction of the value. The data can for instance be represented using more or less bits in a digital message or transmited in analog form. A given value may also be represented using an abstraction or code, such as a discrete value in a given predefined range.

A heavy-duty vehicle 100 comprises a number of actuators, referred to herein as motion support devices (MSD). The MSDs of a vehicle may comprise one or more combustion engines, electric machines, steering actuators, brake systems, active suspension systems, and so on. A heavy-duty vehicle, such as the vehicle 100, is normally over-actuated, which means that a given motion by the vehicle can be obtained by a number of different actuator motion request combinations. Steering can, for instance, be achieved by actuating a power steering system, and also by differential braking on the two sides of the vehicle. An active suspension system can also be used to obtain a certain curvature by the vehicle 100. A global motion request issued, e.g., by a driver or by an autonomous control system, for a given overall vehicle motion behavior can therefore be satisfied in a number of different ways, some good and some not so good in terms of cost, where the cost function may involve aspects such as component wear, energy expenditure, and passenger convenience.

Figure 2 illustrates a computer-implemented control system 200 for vehicle motion management (VMM) of a heavy-duty vehicle 100. A vehicle controller 210 of some sort issues a desired control target 215 which the VMM system is supposed to satisfy, if possible. The control target may comprise a global force request comprising longitudinal and lateral forces to be generated by each vehicle unit of the heavy-duty vehicle 100, such as forces to be generated by the tractor 110 and by the trailer 120 of the example vehicle 100 in Figure 1. The control target may also comprise a target speed profile and curvature to be adhered to by the vehicle 100. A set of global forces acting on the different vehicle units that are required to achieve the speed profile and curvature can often be derived based on a vehicle dynamics model. The control target 215 is transmited to an MSD coordinator function 220, that is configured to determine a set of motion requests 225 to be sent to N different MSDs 230 of the vehicle 100. A sizeable number of different MSD coordination functions are known in the literature, most based on the solution to some form of mathematical optimization problem involving a desired vehicle motion behavior and constraints associated with the different capabilities of the MSDs. To give an example of how the MSD coordination function 220 might operate, consider a control problem where is a vector of MSD motion requests 225, v is a vector that represents a desired set of global vehicle forces 215 to be generated, B is a control effectiveness matrix (obtained, e.g., from the motion model function 240), and x_d is a vector of desired MSD motion requests (also obtained from the motion model function 240). The vector of desired motion requests may, e.g., comprise a default actuator state associated with the smallest energy consumption or the like. The MSD coordination problem can then be cast as x* = arg subject to x_L < x < x_u

Where W_x and W_v are weighting matrices, y is a tuning parameter, and x_t < x < x_u are constraints imposed on the MSD coordination optimization problem.

This optimization problem formulation can be rewritten using well-known matrix manipulation techniques to the form x* = arg subject to Xi < x < x_u where

H = 2 W^T _XW_X + yB^TW^T _vW_vB f^T = -2(x^T _dW^T _xW_x + yv^TW^T _vW_vB

The motion model function 240 is configured to provide models 245 used by the MSD coordination function 220 to allocate motion requests to the different MSDs that together fulfil the control target 215. The motion model function 240 may for instance be configured to provide a relationship between MSD control inputs and global forces. This type of model input is often referred to as the control effectiveness matrix (or “B-matrix”) in the literature and it often comprises a transfer function that maps control inputs x = [x_lt x_lt .... x_w] to global force outputs v. The motion model function 240 may also be configured to provide a model of the losses of the different actuators. This loss model can be used in the MSD coordination function 220 to define a cost function, which can be used in an optimization problem that solves the MSD request allocation problem. The loss model often maps the control inputs sent to MSDs to power losses (ohmic losses, mechanical losses due to friction, etc.). Both the motion model and the loss model could enter the MSD coordination function 220 as equality constraints in a mathematical optimization problem, or in the objective function of the optimization problem.

The MSD coordination function 220 is generally constrained in its allocation of motion requests to the different MSDs by MSD capabilities 255 obtained from an MSD capability function 250. Each MSD has its limits when it comes to actuation. A propulsion device such as an electric machine is for instance associated with limitations on the torque that can be delivered, as is a brake device. The steering system of a vehicle also has its limitations, such as the maximum achievable steering rate and steering angle. These MSD capabilities are considered in the allocation of motion requests 225 to the different MSDs 230. An axle and/or wheel capability function 260 may also be implemented that provides capabilities 265 associated with the different axles of the vehicle 100, and/or the different wheels. This function may, e.g., be configured to determine maximum longitudinal and/or lateral tyre forces that can be generated at a given point in time.

A notable feature in the computer-implemented control system 200 is the fault detection function 270. This fault detection function 270 is arranged to identify one or more faulty MSDs in the plurality of MSDs, and provide adaptation values 271, 272, 273 to the motion model function 240, the MSD capabilities function 250 and the axle/wheel capability function 260, thereby causing the system to adapt the actuator capabilities associated with the one or more faulty MSDs in response to detecting fault by the fault detection function 270.

Figure 3A shows an example of a detected failure in an MSD, wheel, or axle. In this case the second MSD in the control allocation vector x has failed, which means that it is no longer possible to generate any actuation by the MSD. The MSD coordination function 220 then removes the MSD from its list of available MSDs and updates the formulation of the MSD coordination problem.

Figure 3B shows an example of what a detected failure in an MSD can lead to. In this case the nominal capability 310 has been reduced to a smaller capability range 320 as a result of the failure. Figures 3C and 3D show how MSD cost functions can be adapted in response to detecting failure by one or more MSDs, where the solid line is the cost function before the detected failure and the dashed lines are the cost functions after the detected failures.

Figure 4 schematically illustrates functionality 400 for controlling the vehicle 100 by some example motion support devices (MSD) here comprising brake actuators, propulsion actuators, and power steering, with respective controllers collectively referred to herein as MSD control 430. A traffic situation management (TSM) function 410 plans driving operation with a time horizon of 10 seconds or so. This time period corresponds to, e.g., the time it takes for the vehicle 100 to negotiate a curve or the like. The vehicle maneuvers, planned and executed by the TSM function 410, can be associated with acceleration profiles a_req and curvature profiles Creq which describe a desired target vehicle velocity in the vehicle forward direction and turning to be maintained for a given maneuver. The TSM function continuously requests the desired acceleration profiles a_req and steering angles (or curvature profiles c_req) from the VMM system 420 which performs force allocation to meet the requests from the TSM function in a safe and robust manner.

Each wheel 101, 102, 103 on the vehicle 100 has a longitudinal velocity component v_x and a lateral velocity component v_y (in the coordinate system of the wheel or in the coordinate system of the vehicle, depending on implementation). There is a longitudinal tyre force F_x and a lateral tyre force F_y, and also a normal force F_z acting on the wheel. Unless explicitly stated otherwise, the tyre forces are defined in the coordinate system of the wheel, i.e., the longitudinal force is directed in the rolling plane of the wheel, while the lateral tyre force is directed normal to the rolling plane of the wheel.

The TSM function 410 generates vehicle motion requests which may comprise a desired curvature c_req to be followed by the vehicle, and desired vehicle unit accelerations a_req.

The VMM system 420 operates with a time horizon of about 1 second or so, and continuously transforms the acceleration profiles a_req and curvature profiles c_req from the TSM function 410 into MSD motion requests 431, 432, 433 for controlling vehicle motion functions, actuated by the different MSDs of the vehicle 100 which report back capabilities and status information 434, 435, 436 to the VMM function 420, which in turn may be used as constraints in the MSD coordination function 470. One example of such a constraint may be the maximum achievable longitudinal tyre force of a given wheel, a range of torques that can be provided by a given actuator, or a steering angle range. The VMM system 420 performs vehicle state or motion estimation 450, i.e., the VMM system 420 continuously determines a vehicle state s as function of time t comprising positions, speeds, accelerations, and articulation angles of the different units in the vehicle combination by monitoring operations using various sensors 440 arranged on the vehicle 100, often but not always in connection to the MSDs. The vehicle state at a future time instant can also be predicted by a state prediction function 455. This vehicle state prediction function may be realized by a vehicle model having a vehicle state which can be extrapolated into a predicted vehicle state, given a current vehicle state, and optionally also given the current vehicle motion request.

The result of the state estimation 450 and optionally also the state prediction 455, i.e., the estimated vehicle state s at one or more time instants, is input to a force generation module 460 which determines the required global forces V=[Vi, V2] for the different vehicle units to cause the vehicle 100 to move according to the requested acceleration and curvature profiles a_req, c_req, and to behave according to the desired vehicle behavior. This example has two vehicle units. More vehicle units are possible, and also a single vehicle unit, e.g., in case the vehicle is a rigid truck or a passenger car. The required global force vector V is input to an MSD coordination function 470 which allocates tyre forces and coordinates other MSDs such as steering and suspension. The coordination by the MSD coordination function is advantageously performed by taking the longitudinal tyre force generating capabilities of the different wheels into account.

The MSD coordination function outputs an MSD control allocation for the i:th wheel, i.e., an MSD motion request, which may comprise any of a torque Ti, a longitudinal wheel slip Xi, a wheel rotational speed ®i, and/or a wheel steering angle 8i. The coordinated MSDs then together provide the desired lateral Fy and longitudinal Fx forces on the vehicle units, as well as the required moments Mz, to obtain the desired motion by the vehicle combination 100. Thus, according to some aspects of the present disclosure, the VMM system 420 manages both force generation and MSD coordination, i.e., it determines what forces that are required at the vehicle units in order to fulfil the requests from the TSM function 410, for instance to accelerate the vehicle according to a requested acceleration profile requested by TSM and/or to generate a certain curvature motion by the vehicle also requested by TSM. The forces may comprise e.g., yaw moments Mz, longitudinal forces Fx and lateral forces Fy, as well as different types of torques to be applied at different wheels. The forces are determined such as to generate the vehicle behavior which is expected by the TSM function in response to the control inputs generated by the TSM function 410.

A fault detection function 480 monitors sensor signals 445 and the vehicle state 455, and outputs fault detections 485 to the MSD coordination function, where it is used to adapt the MSD control allocation in accordance with adjusted MSD capabilities that reflect the consequences of the detected fault, as discussed above in connection to Figure 2.

Figure 5 schematically illustrates functionality 500 for controlling a wheel 101 on the vehicle 100 to generate a longitudinal wheel tyre Fx and a lateral wheel force Fy, by some example MSDs here comprising a friction brake 550 (such as a disc brake or a drum brake), a propulsion device 530 and a power steering arrangement 540. The friction brake 550 and the propulsion device 530 are examples of wheel torque generating devices, which can be controlled by one or more motion support device control units 430. The control is based on measurement data obtained from, e.g., a wheel speed sensor 510 in combination with data from one or more inertial measurement units 520 and optionally also based on data from other vehicle state sensors, such as radar sensors, lidar sensors, and also vision based sensors such as camera sensors and infra-red detectors.

Figure 6A illustrates an example of wheel speed sensor signals during a tyre explosion event. The graph shows a wheel speed difference metric computed over the wheels of an axle. The dashed line indicates the time instant of the tyre explosion event. It is noted that the signal increases in magnitude and also exhibits an oscillating behavior, which can be used by the fault detection function 270, 480 to determine that a tyre explosion has occurred, which is an event that likely reduces the force generating capabilities of the wheel associated with the tyre explosion event.

Figure 6B is a graph that schematically illustrates a rising temperature in an actuator as a result of failure. The dashed line here indicates a maximum expected operating temperature. When the temperature of an actuator goes above this detection threshold, the fault detection function 270, 480 detects failure in the actuator, and adapts the capabilities of the associated MSD.

To summarize at least some of the discussion up until now, with reference also to Figure 7 that will be discussed below, various aspects of a computer-implemented control system 200, 400, 700 for vehicle motion management of a heavy-duty vehicle 100 has been described. The control systems are intended for use with heavy-duty vehicles 100 that comprise a plurality of MSDs 230, where each MSD is arranged to control at least one actuator 530, 540, 550 of the vehicle 100 based on a motion request 225, 431, 432, 433 received from the computer- implemented control system 200, 400, 700. In other words, the vehicle 100 comprises a number of different actuators, which together control motion by the vehicle. The actuation system on the vehicle is over-actuated, meaning that more than one way of obtaining a given motion by the vehicle normally exists. The control system 200, 400, 700 is arranged to obtain a desired total impact 210, 460 on the motion of the vehicle 100 by the plurality of MSDs. This desired impact may, e.g., comprise a set of global forces to be generated by the actuators, or a change in motion such as an acceleration or a change in lateral force or curvature by the vehicle 100.

The control system 200, 400, 700 comprises an MSD coordination function 220, 470 that is configured to allocate motion requests 225, 431, 432, 433 to the MSDs such that the desired total impact 210, 460 on the motion of the vehicle 100 is obtained, based on a cost function, and on respective actuator capabilities associated with the MSDs. The MSD coordination function normally implements some type of mathematical optimization routine that solves the MSD allocation problem under constraints imposed by the capabilities of the different MSDs. Some MSDs may, e.g., be arranged to generate torque in a given range, which range may also change in dependence of axle speed (common for electric machines) and actuator temperature (commonly seen for friction brakes). According to some aspects, the MSD coordination function 220, 470 is configured to solve a constrained optimization problem, where the constraints are determined based on MSD capabilities. The MSD coordination function 220, 470 may also be configured to solve an optimization problem associated with one or more cost functions, where the cost functions are configured in dependence of any of; an energy expenditure of MSD actuators, a wear incurred on MSD actuators, and a passenger convenience metric, as discussed above.

The control system 200, 400, 700 discussed herein further comprises a fault detection function 270, 480 arranged to identify one or more faulty MSDs in the plurality of MSDs, where the control system 200, 400, 700 is arranged to adapt the cost function and/or the actuator capabilities associated with the one or more faulty MSDs in response to detecting fault by the fault detection function 270, 480. The fault detection function monitors, e.g., vehicle sensor signals and motion behavior in order to detect unexpected patterns in the sensor outputs and/or vehicle motion. A tyre explosion is, for instance, likely to result in unusual wheel speed signals, and may also be detected using tyre pressure monitoring systems (TPMS) and the like. Temperature sensors may be used to monitor actuator temperature, and thus detect when some actuators overheats due to malfunction. When the fault detection function detects malfunction by one or more actuators, the control system adjusts the MSD capabilities and/or the cost functions used by the MSD coordination function as it allocates motion requests between the different MSDs. In case of total MSD breakdown, the MSD is removed from the list of available actuators, and the MSD allocation problem is solved without the failed MSD. Thus, if the steering fails, then the power steering actuators on the vehicle will no longer be part of the motion control by the vehicle in an automatic manner. An exploded tyre will result in less tyre forces, or none at all, being allocated to the wheel or axle comprising the exploded tyre.

The control system 200, 400, 700 may comprise a motion model function 240 that is arranged to adapt at least one cost function associated with actuation by an MSD based on input 271 from the fault detection function 270, 480. Thus, it is understood that a failing MSD may in some cases still be used for motion control of the vehicle, but at an added cost. This is an advantage since the vehicle control space is not restricted as much as if the MSD had been removed from consideration entirely. However, if other actuators exist on the vehicle that allow the control system to fulfill the desired total impact, then it is unlikely that the more expensive failing MSD will be part of the control solution.

According to some aspects the control system also comprises a motion model function 240 arranged to adapt a control effectiveness matrix associated with actuation by the plurality of MSDs based on input 271 from the fault detection function 270, 480. This control effectiveness matrix, of B-matrix as it is normally called, model connections between actuators and forces acting on the vehicle. The control system 200, 400, 700 may also comprise an MSD capabilities function 250 arranged to adapt MSD constraints of the control system based on input 272 from the fault detection function 270, 480, and an axle/wheel capabilities function 260 arranged to adapt axle capabilities and/or wheel capabilities based on input 273 from fault detection function 270, 480. The fault detection function 270, 480 may be configured to identify a faulty MSD in terms of type and location, and to transmit the type and location of the faulty MSD as an output 271, 272, 273 of the fault detection function 270, 480. The fault detection function 270, 480 may also be configured to quantify a magnitude of a failure in a faulty MSD, and to transmit the magnitude of the failure as an output 271, 272, 273 of the fault detection function 270, 480.

Various fault events may be detected and classified by the fault detection function. The literature comprises a plurality of example detection methods for various faults that may occur on a heavy-duty vehicle, and the actual fault detection and classification methods will therefore not be discussed in more detail herein.

The fault detection function 270, 480 may for instance be arranged to detect an explosion of a tyre 101, 102, 103 of the vehicle 100, and to automatically compensate for the explosion by reallocating motion requests away from the actuators associated with the exploded tyre to actuators not affected as much by the explosion.

The fault detection function 270, 480 can also be arranged to detect malfunction in a power steering system 540 of the vehicle 100, and to resort to other types of actuators to maintain the desired curvature of the vehicle 100. Differential braking (steer-by-braking) can for instance be employed in order to compensate for the loss in steering function.

The control system 200, 400, 700 may also, according to some aspects, be arranged to detect malfunction in a service brake 550 of the vehicle 100, and to slow down the vehicle using other available actuators.

The fault detection function 270, 480 can also be arranged to detect malfunction in a communication bus of the vehicle 100, such as an overload in the bus that prevents important data from reaching the intended destination. The computer system may then reallocate motion requests to actuators that are not as affected by the overloaded communications bus, thus mitigating the consequences of the communication bus overload. This type of malfunction may, e.g., relate to an intermittent faut, and not really in the actuator itself. Similarly, the fault could be in a supply of the actuator (air/gas/hydraulic fluid leakage, wires of electric circuitloose connection, etc.).

Actuator overheating in an actuator on the vehicle 100 is another fault condition that can be detected by the fault detection function 270, 480. According to some aspects, the control system 200, 400, 700 is arranged to initially set the MSD capability of a faulty MSD to zero in response to detecting fault, and then gradually increase capability. This way the control system can probe the MSD to see if there is any remaining actuator capability after the fault event, or if the MSD should be removed from the list of available actuators entirely.

Figure 7 is a schematic diagram of a computer system 700 for implementing examples disclosed herein. The computer system 700 is adapted to execute instructions from a computer- readable medium to perform these and/or any of the functions or processing described herein. The computer system 700 may be connected (e.g., networked) to other machines in a LAN, an intranet, an extranet, or the Internet. While only a single device is illustrated, the computer system 700 may include any collection of devices that individually or jointly execute a set (or multiple sets) of instructions to perform any one or more of the methodologies discussed herein. Accordingly, any reference in the disclosure and/or claims to a computer system, computing system, computer device, computing device, control system, control unit, electronic control unit (ECU), processor device, etc., includes reference to one or more such devices to individually or jointly execute a set (or multiple sets) of instructions to perform any one or more of the methodologies discussed herein. For example, a control system may include a single control unit, or a plurality of control units connected or otherwise communicatively coupled to each other, such that any performed function may be distributed between the control units as desired. Further, such devices may communicate with each other or other devices by various system architectures, such as directly or via a Controller Area Network (CAN) bus, etc.

The computer system 700 may comprise at least one computing device or electronic device capable of including firmware, hardware, and/or executing software instructions to implement the functionality described herein. The computer system 700 may include a processor device 702 (may also be referred to as a control unit), a memory 704, and a system bus 706. The computer system 700 may include at least one computing device having the processor device 702. The system bus 706 provides an interface for system components including, but not limited to, the memory 704 and the processor device 702. The processor device 702 may include any number of hardware components for conducting data or signal processing or for executing computer code stored in memory 704. The processor device 702 (e.g., control unit) may, for example, include a general-purpose processor, an application specific processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA), a circuit containing processing components, a group of distributed processing components, a group of distributed computers configured for processing, or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. The processor device may further include computer executable code that controls operation of the programmable device.

The system bus 706 may be any of several types of bus structures that may further interconnect 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 704 may be one or more devices for storing data and/or computer code for completing or facilitating methods described herein. The memory 704 may include database components, object code components, script components, or other types of information structure for supporting the various activities herein. Any distributed or local memory device may be utilized with the systems and methods of this description. The memory 704 may be communicably connected to the processor device 702 (e.g., via a circuit or any other wired, wireless, or network connection) and may include computer code for executing one or more processes described herein. The memory 704 may include non-volatile memory 708 (e.g., read-only memory (ROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), etc.), and volatile memory 710 (e.g., random-access memory (RAM)), or any other medium which can be used to carry or store desired program code in the form of machineexecutable instructions or data structures, and which can be accessed by a computer or other machine with a processor device 702. A basic input/output system (BIOS) 712 may be stored in the non-volatile memory 708 and can include the basic routines that help to transfer information between elements within the computer system 700.

The computer system 700 may further include or be coupled to a non-transitory computer- readable storage medium such as the storage device 714, which may comprise, for example, an internal or external hard disk drive (HDD) (e.g., enhanced integrated drive electronics (EIDE) or serial advanced technology attachment (SATA)), HDD (e.g., EIDE or SATA) for storage, flash memory, or the like. The storage device 714 and other drives associated with computer- readable media and computer-usable media may provide non-volatile storage of data, data structures, computer-executable instructions, and the like.

A number of modules can be implemented as software and/or hard coded circuitry to implement the functionality described herein in whole or in part. The modules may be stored in the storage device 714 and/or in the volatile memory 710, which may include an operating system 716 and/or one or more program modules 718. All or a portion of the examples disclosed herein may be implemented as a computer program product 720 stored on a transitory or non-transitory computer-usable or computer-readable storage medium (e.g., single medium or multiple media), such as the storage device 714, which includes complex programming instructions (e.g., complex computer-readable program code) to cause the processor device 702 to carry out the steps described herein. Thus, the computer-readable program code can comprise software instructions for implementing the functionality of the examples described herein when executed by the processor device 702. The processor device 702 may serve as a controller or control system for the computer system 700 that is to implement the functionality described herein.

The computer system 700 also may include an input device interface 722 (e.g., input device interface and/or output device interface). The input device interface 722 may be configured to receive input and selections to be communicated to the computer system 700 when executing instructions, such as from a keyboard, mouse, touch-sensitive surface, etc. Such input devices may be connected to the processor device 702 through the input device interface 722 coupled to the system bus 706 but can be connected through other interfaces such as a parallel port, an Institute of Electrical and Electronic Engineers (IEEE) 1394 serial port, a Universal Serial Bus (USB) port, an IR interface, and the like. The computer system 700 may include an output device interface 724 configured to forward output, such as to a display, a video display unit (e.g., a liquid crystal display (LCD) or a cathode ray tube (CRT)). The computer system 700 may also include a communications interface 716 suitable for communicating with a network as appropriate or desired.

Figure 8 is a flow chart illustrating methods that correspond to the different technical features of the computer system and the vehicles discussed herein. The flow chart illustrates a computer- implemented method for vehicle motion management, VMM, of a heavy-duty vehicle 100, where the vehicle 100 comprises a plurality of motion support devices, MSD, 230 and where each MSD is arranged to control at least one actuator 530, 540, 550 of the vehicle 100 based on a motion request 225, 431, 432, 433 received from the computer-implemented control system 200, 400, 700, the method comprising obtaining SI a desired total impact 210, 460 on the motion of the vehicle 100 by the plurality of MSDs, allocating S2 motion requests 225, 431, 432, 433 to the MSDs such that the desired total impact 210, 460 on the motion of the vehicle 100 is obtained, based on a cost function, and on respective actuator capabilities associated with the MSDs, identifying S3 one or more faulty MSDs in the plurality of MSDs, and adapting S4 the cost function and/or the actuator capabilities associated with the one or more faulty MSDs in response to detecting fault by the fault detection function 270, 480.

It is appreciated that the different parts of the method can be performed in other orders than the illustrated order in Fig. 8, i.e., the part S2 could for instance be performed as the last step (SI, S3, S4, S2).

Figure 9 illustrates a computer readable medium 910 carrying a computer program comprising program code means 920 for performing the methods illustrated in Figure 8 and the techniques discussed herein, when said program product is run on a computer. The computer readable medium and the code means may together form a computer program product 900.

The operational steps described in any of the exemplary aspects herein are described to provide examples and discussion. The steps may be performed by hardware components, may be embodied in machine-executable instructions to cause a processor to perform the steps, or may be performed by a combination of hardware and software. Although a specific order of method steps may be shown or described, the order of the steps may differ. In addition, two or more steps may be performed concurrently or with partial concurrence.

The terminology used herein is for the purpose of describing particular aspects only and is not intended to be limiting of the disclosure. As used herein, the singular forms "a," "an," and "the" 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 will be further understood that the terms "comprises," "comprising," "includes," and/or "including" when used herein specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

It will 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. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element without departing from the scope of the present disclosure.

Relative terms such as "below" or "above" or "upper" or "lower" or "horizontal" or "vertical" may be used herein to describe a relationship of one element to another element as illustrated in the Figures. It will be understood that these terms and those discussed above are intended to encompass different orientations of the device in addition to the orientation depicted in the Figures. It will be understood that when an element is referred to as being "connected" or "coupled" to another element, it can be directly connected or coupled to the other element, or intervening elements may be present. In contrast, when an element is referred to as being "directly connected" or "directly coupled" to another element, there are no intervening elements present.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. It will be further understood that terms used herein should be interpreted as having a meaning consistent with their meaning in the context of this specification and the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

It is to be understood that the present disclosure is not limited to the aspects described above and illustrated in the drawings; rather, the skilled person will recognize that many changes and modifications may be made within the scope of the present disclosure and appended claims. In the drawings and specification, there have been disclosed aspects for purposes of illustration only and not for purposes of limitation, the scope of the inventive concepts being set forth in the following claims.

Claims

1. A computer-implemented control system (200, 400, 700) for vehicle motion management, VMM, of a heavy-duty vehicle (100), where the vehicle (100) comprises a plurality of motion support devices, MSD, (230) and where each MSD is arranged to control at least one actuator (530, 540, 550) of the vehicle (100) based on a motion request (225, 431, 432, 433) received from the computer-implemented control system (200, 400, 700), the control system (200, 400, 700) being arranged to obtain a desired total impact (210, 460) on the motion of the vehicle (100) by the plurality of MSDs, the control system (200, 400, 700) comprising an MSD coordination function (220, 470) configured to allocate motion requests (225, 431, 432, 433) to the MSDs such that the desired total impact (210, 460) on the motion of the vehicle (100) is obtained, based on a cost function, and on respective actuator capabilities associated with the MSDs, the control system (200, 400, 700) further comprising a fault detection function (270, 480) arranged to identify one or more faulty MSDs in the plurality of MSDs, where the control system (200, 400, 700) is arranged to adapt the cost function and/or the actuator capabilities associated with the one or more faulty MSDs in response to detecting fault by the fault detection function (270, 480).

2. The control system (200, 400, 700) according to claim 1, arranged to transmit motion requests to a plurality of MSDs comprising at least one propulsion device (530), at least one friction brake (550), and a power steering system (540).

3. The control system (200, 400, 700) according to claim 1 or 2, where the MSD coordination function (220, 470) is configured to solve a constrained optimization problem, where the constraints are determined based on MSD capabilities.

4. The control system (200, 400, 700) according to any previous claim, where the MSD coordination function (220, 470) is configured to solve an optimization problem associated with one or more cost functions, where the cost functions are configured in dependence of any of; an energy expenditure of MSD actuators, a wear incurred on MSD actuators, and a passenger convenience metric.

5. The control system (200, 400, 700) according to any previous claim, comprising a motion model function (240) arranged to adapt at least one cost function associated with actuation by an MSD based on input (271) from the fault detection function (270, 480).

6. The control system (200, 400, 700) according to any previous claim, comprising a motion model function (240) arranged to adapt a control effectiveness matrix associated with actuation by the plurality of MSDs based on input (271) from the fault detection function (270, 480).

7. The control system (200, 400, 700) according to any previous claim, comprising an MSD capabilities function (250) arranged to adapt MSD constraints of the control system based on input (272) from the fault detection function (270, 480).

8. The control system (200, 400, 700) according to any previous claim, comprising an axle/wheel capabilities function (260) arranged to adapt axle capabilities and/or wheel capabilities based on input (273) from fault detection function (270, 480).

9. The control system (200, 400, 700) according to any previous claim, where the desired total impact (210, 460) on the motion of the vehicle (100) comprises a global force vector.

10. The control system (200, 400, 700) according to any previous claim, where the fault detection function (270, 480) is configured to identify a faulty MSD in terms of type and location, and to transmit the type and location of the faulty MSD as an output (271, 272, 273) of the fault detection function (270, 480).

11. The control system (200, 400, 700) according to any previous claim, where the fault detection function (270, 480) is configured to quantify a magnitude of a failure in a faulty MSD, and to transmit the magnitude of the failure as an output (271, 272, 273) of the fault detection function (270, 480).

12. The control system (200, 400, 700) according to any previous claim, where the fault detection function (270, 480) arranged to detect an explosion of a tyre (101, 102, 103) of the vehicle (100).

13. The control system (200, 400, 700) according to any previous claim, where the fault detection function (270, 480) arranged to detect malfunction in a power steering system (540) of the vehicle (100).

14. The control system (200, 400, 700) according to any previous claim, where the fault detection function (270, 480) arranged to detect malfunction in a service brake (550) of the vehicle (100).

15. The control system (200, 400, 700) according to any previous claim, where the fault detection function (270, 480) arranged to detect malfunction in a communication bus of the vehicle (100).

16. The control system (200, 400, 700) according to any previous claim, where the fault detection function (270, 480) arranged to detect malfunction in an actuator supply line of the vehicle (100), such as a pneumatic air line, a gas line, a hydraulic line, or an electrical supply.

17. The control system (200, 400, 700) according to any previous claim, where the fault detection function (270, 480) arranged to detect actuator overheating in an actuator on the vehicle (100).

18. The control system (200, 400, 700) according to any previous claim, arranged to initially set an MSD capability of a faulty MSD to zero in response to detecting fault, and then gradually increase capability.

19. A computer-implemented method for vehicle motion management, VMM, of a heavy- duty vehicle (100), where the vehicle (100) comprises a plurality of motion support devices, MSD, (230) and where each MSD is arranged to control at least one actuator (530, 540, 550) of the vehicle (100) based on a motion request (225, 431, 432, 433) received from the computer-implemented control system (200, 400, 700), the method comprising obtaining (SI) a desired total impact (210, 460) on the motion of the vehicle (100) by the plurality of MSDs, allocating (S2) motion requests (225, 431, 432, 433) to the MSDs such that the desired total impact (210, 460) on the motion of the vehicle (100) is obtained, based on a cost function, and on respective actuator capabilities associated with the MSDs, identifying (S3) one or more faulty MSDs in the plurality of MSDs, and adapting (S4) the cost function and/or the actuator capabilities associated with the one or more faulty MSDs in response to detecting fault by the fault detection function (270, 480).

20. A computer program product comprising program code for performing, when executed by the processing circuitry, the method of claim 19.

21. A non-transitory computer-readable storage medium comprising instructions, which when executed by processing circuitry, cause the processing circuitry to perform the method of claim 19.