Dynamic roll control system for a machine

Abstract

A dynamic roll control system (33) generates a ground speed signal indicative of a current speed and compares the current speed to a desired speed. The desired speed is determined based on machine characteristics, a payload of a cargo bed (22), a yaw angular velocity of the cargo bed, a pitch angular velocity of the cargo bed, and a roll angle of the cargo bed. When the current speed of the machine exceeds the desired speed, a controller (31) generates a prime mover control signal to control operation of a prime mover (17) to slow the machine so that the current speed does not exceed the desired speed.

Description

Technical Field

[0001] The present invention generally relates to a rollover control system, and more specifically, to a dynamic rollover control system that utilizes the dynamics of a power transmission system to reduce the likelihood of a machine rolling over. Background Technology

[0002] Trailer trucks, articulated trucks, and other types of machinery are commonly used for load handling in industries such as mining, construction, agriculture, transportation, or any other related operations. Extensive training may be required to make an operator a skilled or even intermediate-level operator.

[0003] When hauling a payload, machine operators may attempt to operate the machine as quickly as possible to minimize the time between loading and unloading points. However, some machines, particularly articulated trucks, can become relatively unstable at high speeds when heavily loaded within the dump truck body. Specifically, when operating the machine at excessive speeds around curves, centripetal forces can cause the trailer or dump truck body portion to tip over or roll over. Furthermore, in certain situations, such as with articulated trucks, the cab and dump truck body may move significantly independently relative to each other (e.g., swaying and / or tilting). Therefore, while the machine operator may feel the centripetal force in the cab, they may not feel the force or movement in the dump truck body. While such rollover events may not result in severe damage to the machine, the time spent righting the dump truck body and cleaning up spilled material can significantly reduce material handling efficiency.

[0004] US Patent Publication No. 2017 / 0225639 discloses a rollover detection system that performs dynamic stability analysis based on triaxial angular velocity and / or triaxial angular velocity analysis. The system may include an alarm system containing sirens and light strips. The system may further include a memory for storing data and static and dynamic performance information of the vehicle.

[0005] The foregoing background discussion is intended to assist the reader only. It is not intended to limit the innovations described herein, nor to limit or expand the prior art discussed. Therefore, the foregoing discussion should not be construed as indicating that any particular element of an existing system is unsuitable for use with the innovations described herein, nor is it intended to indicate that any element is essential for implementing the innovations described herein. The implementation and application of the innovations described herein are defined by the appended claims. Summary of the Invention

[0006] In one aspect, a dynamic rollover control system for a machine includes a prime mover, a ground drive mechanism, a cargo box, a load sensor, a yaw rate sensor, a pitch rate sensor, a roll angle sensor, a ground speed sensor, and a controller. The ground drive mechanism is operatively connected to the prime mover. The cargo box carries the load. The load sensor generates a load signal indicating the load of the cargo box. The yaw rate sensor generates a yaw rate signal indicating the yaw rate of the cargo box. The pitch rate sensor generates a pitch rate signal indicating the pitch rate of the cargo box. The roll angle sensor generates a roll angle signal indicating the roll angle of the cargo box. The ground speed sensor generates a ground speed signal indicating the current speed of the machine. The controller accesses the machine's characteristics, determines the cargo box's effective load based on the effective load signal, determines the cargo box's yaw rate based on the yaw rate signal, determines the cargo box's tilt rate based on the pitch rate signal, determines the cargo box's tilt angle based on the roll angle signal, and determines the cargo box's desired speed based on the machine characteristics, cargo box's effective load, cargo box yaw rate, cargo box tilt rate, and cargo box roll angle. The controller further determines the machine's current speed based on the ground speed signal, and when the machine's current speed exceeds the desired speed, generates a prime mover control signal to control the prime mover's operation to decelerate the machine, thereby ensuring the current speed does not exceed the desired speed.

[0007] On the other hand, a stability control method for a machine cargo compartment includes accessing machine characteristics, determining the cargo compartment's load based on a load signal from a load sensor, determining the cargo compartment's yaw rate based on a yaw rate signal from a yaw rate sensor, determining the cargo compartment's tilt rate based on a tilt rate signal from a pitch rate sensor, determining the cargo compartment's tilt angle based on a tilt angle signal from a roll rate sensor, and determining a desired speed for the cargo compartment based on machine characteristics, the cargo compartment's load, yaw rate, tilt rate, and tilt angle. The method further includes determining the machine's current speed based on a ground speed signal from a ground speed sensor, and when the machine's current speed exceeds the desired speed, generating a prime mover control signal to control the operation of the machine's prime mover to decelerate the machine, thereby ensuring that the current speed does not exceed the desired speed.

[0008] In another aspect, a machine includes a front frame section, a rear frame section, a prime mover, a cargo box, a load sensor, a yaw rate sensor, a pitch rate sensor, a roll angle sensor, a ground speed sensor, and a controller. The front frame section includes a front grounding drive mechanism. The rear frame section includes a rear grounding drive mechanism, and the rear frame section is operatively connected to the front frame section. The prime mover is operatively connected to at least one of the front and rear grounding drive mechanisms. The cargo box is operatively connected to the rear frame section for carrying a load. The load sensor generates a load signal indicating the load of the cargo box. The yaw rate sensor generates a yaw rate signal indicating the yaw rate of the cargo box. The pitch rate sensor generates a pitch rate signal indicating the pitch rate of the cargo box. The roll angle sensor generates a roll angle signal indicating the roll angle of the cargo box. The ground speed sensor generates a ground speed signal indicating the current speed of the machine. The controller accesses the machine's characteristics, determines the cargo box's effective load based on the effective load signal, determines the cargo box's yaw rate based on the yaw rate signal, determines the cargo box's tilt rate based on the pitch rate signal, determines the cargo box's tilt angle based on the roll angle signal, and determines the cargo box's desired speed based on the machine characteristics, cargo box's effective load, cargo box yaw rate, cargo box tilt rate, and cargo box roll angle. The controller further determines the machine's current speed based on the ground speed signal, and when the machine's current speed exceeds the desired speed, generates a prime mover control signal to control the prime mover's operation to decelerate the machine, thereby ensuring the current speed does not exceed the desired speed. Attached Figure Description

[0009] The invention is illustrated by way of example in the accompanying drawings, but is not limited thereto, wherein the same reference numerals denote similar elements, and wherein:

[0010] Figure 1 A schematic diagram of a machine that can employ the principles disclosed herein;

[0011] Figure 2 To and Figure 1 A block diagram of a dynamic rollover control system used in conjunction with the machines shown.

[0012] Figure 3 This is a schematic diagram of the force diagram of a free body, used to describe... Figure 1 The force on the machine shown;

[0013] Figure 4 To and Figure 3 A similar view, but in which the machine is rotating on a slope;

[0014] Figure 5 To and Figure 4 A similar view, but with the slope tilted in the opposite direction;

[0015] Figure 6 It shows Figure 1 The monitor in the driver's cab of the machine shown; and

[0016] Figure 7 for Figure 2 The flowchart shown illustrates the operation of the dynamic rollover control system. Detailed Implementation

[0017] Figure 1 A portion of an exemplary work site 100 is shown, in which multiple mobile machines perform material handling operations. Work site 100 may include, for example, a mine, landfill, quarry, construction site, road construction site, or any other type of work site. The machines may perform any of a variety of desired operations at work site 100, operations that may require the machines to generally traverse work site 100. As shown, work site 100 includes haulage trucks, such as articulated trucks 10, for transporting materials from a loading location (not shown) to a dumping location (not shown) and then back for reloading.

[0018] The articulated truck 10 includes a front frame portion 11 and a rear frame portion 12 coupled at an articulated joint 13 forming an articulated shaft 110. The front frame portion 11 may be supported by a grounded drive mechanism such as front wheels 14, and the front frame portion may support an operator console or cab 15 and a drive system generally indicated as 16. The drive system 16 may include a prime mover, such as an internal combustion engine generally indicated as 17, operatively connected to transmit power to a transmission generally indicated as 18, which includes multiple gears. The transmission 18 can then be used to transmit power to the grounded drive mechanism (e.g., front wheels 14) via a shaft 19 using any known means.

[0019] The rear frame section 12 may be supported by a ground drive mechanism such as the rear wheels 20, and the rear frame section supports the cargo box or dump truck body 22. In response to a lifting command (e.g., a command issued by an operator located in the cab 15), the dump truck body 22 may be selectively pivoted between a loading position (as shown) and a dumping or unloading position (as shown by the dashed line) via one or more lifting cylinders 23.

[0020] The service brakes, generally indicated by 24, can be associated with each of the front wheels 14 and the rear wheels 20. Display 60 ( Figure 6 It can be installed in the driver's cab 15, which will be described in further detail below.

[0021] The articulated truck 10 may include a control system 30, generally as follows: Figure 1The arrows in the diagram indicate their association with the machine. The control system 30 may use one or more sensors that provide data and input signals representing various operating parameters of the articulated truck 10 and the environment of the work site 100 where the machine operates. The control system 30 may include an electronic control module or controller 31 and multiple sensors associated with the articulated truck 10.

[0022] Controller 31 may be an electronic controller that operates logically to perform operations, execute control algorithms, store and retrieve data, and perform other necessary operations. Controller 31 may include or access memory, auxiliary storage devices, a processor, and any other components used to run the application. Memory and auxiliary storage devices may be in the form of controller-accessible read-only memory (ROM) or random access memory (RAM) or integrated circuits. Various other circuits may be associated with controller 31, such as power supply circuits, signal conditioning circuits, driver circuits, and other types of circuits.

[0023] Controller 31 may be a single controller, or may include more than one controller configured to control various functions and / or features of the articulated truck 10. The term "controller" is intended to be used in its broadest sense to include one or more controllers and / or microprocessors that may be associated with the articulated truck 10 and can cooperatively control various functions and operations of the machine. The functionality of controller 31 may be implemented in hardware and / or software, without regard to functionality. Controller 31 may rely on one or more data maps relating to the operating conditions and operating environment of the articulated truck 10 and the work site 100, which may be stored in the controller's memory. Each of these data maps may include a set of data in the form of tables, graphs, and / or equations.

[0024] The control system 30 and controller 31 may be located on the articulated truck 10, or they may be distributed with components located remotely on the machine, such as at a control center (not shown). The functionality of the control system 30 may be distributed such that some functions are performed on the articulated truck 10, while others are performed remotely. In this case, the control system 30 may include a communication system, such as a wireless network system (not shown), for transmitting signals between the articulated truck 10 and the system located remotely on the machine, such as at a control center.

[0025] The articulated truck 10 may be equipped with multiple machine sensors that provide data indicating (directly or indirectly) various operating parameters of the machine and / or the operating environment of the machine. The term "sensor" is intended to be used in its broadest sense to include one or more sensors and associated components that may be associated with and cooperate with the articulated truck 10 to sense various functions, operations and operating characteristics of the machine and / or environmental conditions of the machine's operation.

[0026] refer to Figure 2 A ground speed sensor 35 can be configured to generate a ground speed signal or data indicating the speed at which the articulated truck 10 operates. In one embodiment, the ground speed sensor 35 may be configured as a wheel speed sensor that measures the rotational speed of one or more of the front wheels 14 or the rear wheels 20. The controller 31 can use the known dimensions of the front wheels 14 or the rear wheels 20, along with the wheel speed, to determine the ground speed of the articulated truck 10. In another embodiment, the ground speed sensor 35 may use data from a position sensor to determine the ground speed of the articulated truck 10. In such an embodiment, the position sensor may include one or more sensors that interact with a positioning system, such as a Global Navigation Satellite System or a Global Positioning System. Other ways of determining the ground speed of the articulated truck 10 are also contemplated by those skilled in the art.

[0027] A pitch rate sensor 36 can be provided to generate a pitch rate signal or data indicating the pitch rate of the dump truck body 22. The pitch rate sensor 36 can be used to determine the pitch rate or the rate of change of the angle between the front and rear of the dump truck body 22. If necessary, a pitch rate sensor can also be provided for the front frame section 11. In one embodiment, a multi-axis inertial measurement unit (such as...) Figure 1 The six-axis inertial measurement unit (referred to as 25 on the front frame section 11 and 26 on the dump truck body 22) can be used as a pitch angular velocity sensor.

[0028] A pitch angle sensor 37 can be provided to generate a pitch angle signal or data indicating the pitch angle of the dump truck body 22. The pitch angle sensor 37 can be used to determine the pitch angle or the angle between the front and rear of the dump truck body 22. If necessary, a pitch angle sensor can also be provided for the front frame portion 11. In one embodiment, inertial measurement units 25 and 26, respectively located on the front frame portion 11 and the dump truck body 22, can be used as pitch angle sensors.

[0029] A roll angle sensor 38 can be provided to generate a roll angle signal or data indicating the roll angle of the dump truck body 22. The roll angle sensor 38 can be used to determine the roll angle or the angle between the right and left sides of the dump truck body 22 along the longitudinal axis of the dump truck body. If necessary, a roll angle sensor can also be provided for the front frame portion 11. In an embodiment, inertial measurement units 25 and 26, respectively located on the front frame portion 11 and the dump truck body 22, can be used as roll angle sensors.

[0030] A yaw rate sensor 39 can be provided to generate a yaw rate signal or data indicating the yaw rate of the dump truck body 22. The yaw rate sensor 39 can be used to determine the yaw rate or the speed at which the dump truck body 22 rotates about a vertical axis (i.e., to the right or left). If desired, a yaw rate sensor, denoted as a second yaw rate sensor 40, can also be provided for the front frame portion 11. In an embodiment, inertial measurement units 25 and 26, respectively located on the front frame portion 11 and the dump truck body 22, can be used as yaw rate sensors.

[0031] A dump truck body lift sensor 41 can be provided to generate a lift angle signal or data indicating the angle of the dump truck body 22 relative to the rear frame portion 12 of the articulated truck 10. In one embodiment, an inertial measurement unit 26 on the dump truck body 22 can be used as the dump truck body lift sensor 41. In another embodiment, the dump truck body lift sensor 41 can be configured as a sensor 41a (…) located on one or more lifting cylinders 23. Figure 1 ).

[0032] A load sensor 42 can be provided to generate a load signal or data indicating the weight of the load within the dump truck body 22. In an embodiment, an inertial measurement unit 26 on the dump truck body 22 can be used as the load sensor 42. The controller 31 can be used to monitor the signal of the inertial measurement unit 26 and determine that the dump truck body has been loaded after a predetermined number of readings of the inertial measurement unit consistent with the loading operation. For example, during the loading operation, the inertial measurement unit 26 can indicate two or three significant vertical movements (e.g., acceleration) of the dump truck body 22 without intervening in the horizontal movement of the inertial measurement unit, followed by the horizontal movement of the dump truck body. As the articulated truck 10 moves around the work site, the controller 31 can start from an assumed load value and adjust the load value based on operating conditions. For example, based on a given engine speed, fuel consumption rate, assumed load value, and a known gradient of the slope in which the articulated truck 10 is moving, the controller 31 can determine the expected speed or acceleration. The controller 31 can determine the actual load value based on the degree to which the actual speed or acceleration deviates from the expected speed or acceleration.

[0033] Other payload sensor configurations 42 are also considered. For example, the pressure inside the lifting cylinder 23 can be measured, and this pressure can then be used to determine the payload. Furthermore, strain gauges can be installed on the dump truck body 22.

[0034] A prime mover or engine speed sensor 43 can be provided to generate an engine speed signal or data indicating the speed of engine 17. A transmission speed sensor 44 can be provided to generate a transmission speed signal or data indicating the speed of transmission 18. A fuel quantity sensor 45 can be provided to generate a fuel quantity signal or data indicating the amount of fuel supplied to engine 17. The engine speed sensor 43 and fuel quantity sensor 45, combined with the characteristics of transmission speed sensor 44 and / or transmission 18, can be used as a torque sensor to determine the amount of torque or power supplied by engine 17.

[0035] During operation, if the centripetal moment generated by the centripetal force on the dump truck body 22 exceeds the gravitational moment generated by the net weight of the dump truck body, the dump truck body 22 may begin to tip over. Therefore, the control system 30 may include a dynamic rollover control system 33 for the possibility of the dump truck body 22 tipping over. The function of the dynamic rollover control system 33 is to keep the centripetal moment on the dump truck body 22 below or less than the gravitational moment on the dump truck body. To this end, the dynamic rollover control system 33 keeps the speed of the dump truck body 22 below the speed at which the centripetal moment will exceed the gravitational moment. Such a maximum speed is sometimes referred to herein as the critical speed.

[0036] In operation, the dynamic rollover control system 33 can incorporate a safety factor relative to a critical speed. The critical speed, adjusted for the safety factor, can be referred to as the desired speed of the dump truck body 22 or the desired speed of the machine. In one example, the safety factor can be between 1.1 and 3.0. In another example, the safety factor may be between 1.3 and 2.2. In a further example, the safety factor can be approximately 1.6.

[0037] The dynamic rollover control system 33 may initially attempt to control the speed or operation of the articulated truck 10 by controlling the operation of the engine 17, and then further rely on the service brake 24 as necessary. For example, if the machine is operating slightly faster than (e.g., 5%) the desired speed, the dynamic rollover control system 33 may not need to significantly alter the operation of the engine 17 to reduce the actual speed of the machine below the desired speed. However, if the machine is operating significantly faster than (e.g., 15%) the desired speed, the dynamic rollover control system 33 may significantly reduce the fuel supply to the engine 17 to reduce the actual speed of the machine below the desired speed. In instances where the machine is operating at a speed much greater than (e.g., 25%) the desired speed, the dynamic rollover control system 33 may need not only to significantly reduce the fuel supply to the engine 17, but also to apply the service brake 24 to reduce the actual speed of the machine below the desired speed.

[0038] In one embodiment, the dynamic rollover control system 33 can be based on Figure 3 The free-body force diagram shown determines the maximum or critical velocity v. critical The dump truck body 22 is positioned on the horizontal surface 101 and rotates as indicated by arrow 102. Critical speed v critical It can be represented as:

[0039]

[0040] Among them, F gz Let w be the gravitational force along the z-axis. CG F is the distance along the y-axis between the center of gravity 27 of the dump truck body 22 and the engagement position 28 of the rear wheel 20 with the horizontal surface 101. h The force at the hinge joint 13 at the front of the dump truck body 22 tends to rise due to the imbalance of the front frame section 11. h The distance along the y-axis between the articulated joint 13 and the engagement position 28 between the rear wheel 20 and the horizontal surface 101, and m is the mass of the effective load inside the dump truck body. h is the yaw rate of the dump truck body 22 rotating about the z-axis. CG The distance along the z-axis between the center of gravity 27 of the dump truck body 22 and the engagement position 28 of the rear wheel 20 with the horizontal surface 101.

[0041] exist Figure 3 In the middle, the gravity F along the z-axis gz Let 50 represent the distance w along the y-axis between the center of gravity 27 of the dump truck body 22 and the engagement position 28 of the rear wheel 20 with the horizontal surface 101. CG Let 51 represent the hinge joint force F at hinge joint 13. hLet 52 denote the distance w along the y-axis between the articulated joint 13 and the engagement position 28 of the rear wheel 20 on the horizontal surface 101. h Let 53 represent the centripetal force caused by the rotation of the dump truck body 22 about the z-axis; let 54 represent the distance h along the z-axis between the center of gravity 27 of the dump truck body 22 and the engagement position 28 of the rear wheel 20 with the horizontal surface 101. CG The frictional force generated by the engagement of the rear wheel 20 with the horizontal surface 101, which is opposite to the centripetal force 54, is represented by 55. The normal force at the engagement point of the rear wheel 20 with the horizontal surface 101, which is opposite to the resultant force of gravity 50 and articulated joint force 52, is represented by 56.

[0042] However, if the articulated truck 10 operates on a non-horizontal surface, then the critical speed v is used to determine... critical The equations should further consider the slope of the surfaces on which the articulated truck operates. For example, refer to... Figure 4 In one embodiment, the dynamic rollover control system 33 can determine the maximum or critical velocity v based on a free-body force diagram. critical The dump truck body 22 is positioned along the slope 103 at an angle 104 in the first direction and the dump truck body turns away from the slope as shown by arrow 105.

[0043] Critical velocity v critical It can be represented as:

[0044]

[0045] Equation (2) is similar to equation (1), but with the addition of the following term: gravity F along the y-axis. gy The longitudinal tilt angular velocity of the dump truck body rotating about the y-axis It should be pointed out that, such as Figure 3 As shown, the y-axis and z-axis are rotated with the slope 103, so that the y-axis is parallel to the slope and the z-axis is perpendicular to the slope.

[0046] Similarly, the dynamic rollover control system 33 can utilize Figure 4 The free-body force diagram and the following conditions determine the critical velocity v. critical Among them, the dump truck body 22 is in contact with Figure 3 In the opposite direction shown, the dump truck is positioned at an angle of 107 along the slope 106 in the second direction and the dump truck body turns toward the slope as indicated by arrow 109.

[0047]

[0048] It will be obvious to those skilled in the art that equation (3) is the same as equation (2), but the signs of some terms have changed (i.e., from positive to negative or from negative to positive) to reflect the angle changes of slopes 103 and 106.

[0049] Although the critical velocity v can be determined using equations (1)-(3) as described above. critical However, the dynamic rollover control system 33 can actually use the critical speed with a safety factor without departing from the conception of this paper. The critical speed v can be determined by modifying equations (1)-(3) or by using equations (1)-(3). critical The safety margin is then added by multiplying the critical speed by a safety factor. Therefore, as used in this paper, references to the application of the desired speed sometimes, but not always, include a safety margin.

[0050] The dynamic rollover control system 33 can generate a prime mover control signal 46 to control the operation of the prime mover (e.g., engine 17) to slow or reduce the speed of the articulated truck 10 so that it does not exceed a desired speed. To this end, in one embodiment, the dynamic rollover control system 33 can reduce the power output of the engine 17. For example, the dynamic rollover control system 33 can monitor the amount of fuel supplied to the engine 17 and reduce the speed of the articulated truck 10 by controlling the amount of fuel supplied to the engine.

[0051] The dynamic rollover control system 33 may also include a power loss feedforward function, which optimizes or improves the way the current speed of the dump truck body 22 is controlled to keep the speed of the dump truck body below a desired speed. In this way, the feedforward function of the dynamic rollover control system 33 can calculate or determine the amount of power loss that will occur or is occurring based on one or more power loss factors. Therefore, the dynamic rollover control system 33 can control or require the engine speed to decrease, taking into account the power loss factors, so that the speed of the articulated truck is reduced below the desired speed.

[0052] Power loss factors may include engine losses, transmission losses, output transfer gear and shaft losses, rolling resistance losses, scrubbing losses, and gains / losses due to operation on inclines. Engine losses may include frictional and other losses depending on the rotational speeds of the engine 17 and transmission 18 determined by engine speed sensor 43. Transmission losses may include frictional and other losses depending on the rotational speed of transmission 18 determined by transmission speed sensor 44. In one embodiment, output transfer gear and shaft losses may include frictional and other losses depending on the speed of the articulated truck 10 determined by ground speed sensor 35.

[0053] Rolling resistance loss can be determined by a rolling resistance estimator of the control system 30 or operably associated therewith, which is used to determine an estimate of the rolling resistance encountered by the articulated truck 10. In some cases, rolling resistance loss can be significant because the articulated truck 10 may operate under a wide range of operating conditions, such as from mud to paved surfaces. The rolling resistance estimator can determine the power output of the engine 17, the load within the dump truck body 22, and the slope or incline of the articulated truck's operation, and then compare the actual ground speed with the expected ground speed. In some cases, rolling resistance loss can also be based on the speed of the articulated truck 10 determined by the ground speed sensor 35. In one instance, an actual ground speed greater than expected may indicate that the machine is operating on a harder material than expected, while an actual ground speed lower than expected may indicate that the machine is operating on a softer material than expected.

[0054] Scrubbing losses can be determined based on the yaw rate determined by the yaw rate sensor 39, and in some cases, based on the type of material on which the articulated truck 10 travels. Losses due to operation on slopes can be calculated based on the pitch rate of the dump truck body 22. For example, when the articulated truck 10 travels uphill, the slope causes a power loss, while when the articulated truck travels downhill, the slope causes a power gain (or a negative loss).

[0055] In some situations, the articulated truck 10 may travel at extremely high speeds, such that the reduction in engine speed, together with the power loss associated with the feedforward function, may not be sufficient to slow the machine below the desired speed. In such cases, the dynamic rollover control system 33 may also generate a braking command or control signal 47 to apply the service brake 24 to further decelerate the machine. There are also instances where, even if the reduction in engine speed, together with the feedforward function, is sufficient to slow the articulated truck below the desired speed, it may still be necessary to apply the service brake 24.

[0056] The display 60 may include a stability indicator 61 that indicates the current stability of the dump truck body 22 of the articulated truck 10. In one embodiment, the stability indicator 61 may include a first zone 62 and a second zone 63. Although a third zone 64 is indicated in the figures for clarity, it may not be included in the stability indicator 61. In the first zone 62, the articulated truck 10 operates below a desired speed (i.e., the critical speed calculated with a safety factor). In the second zone 63, the articulated truck 10 operates faster than the desired speed but does not exceed the critical speed (i.e., without considering a safety factor). In the third zone 64, the articulated truck 10 exceeds the critical speed and is therefore likely to overturn.

[0057] In one embodiment, the stability indicator 61 may include a dial gauge 65 for expressing the speed of the articulated truck 10 as a percentage of the desired speed. In another embodiment, the stability indicator 61 may use a color-coding system such as green, yellow, and red to represent the speed of the articulated truck 10, with green in a first zone 62, red in a second zone 63, and yellow spanning the intersection of the first and second zones.

[0058] If needed, in addition to the stability indicator 61, the dynamic rollover control system 33 can also generate an alarm signal 66 when the desired speed is exceeded. Figure 2 Alarm signal 66 can generate any one or all of the following: a visible or audible alarm for the operator on the vehicle, a message sent to the outside of the articulated truck 10, or an event recorded in the controller 31.

[0059] Industrial applicability

[0060] The industrial applicability of the system described herein is readily apparent from the preceding discussion. The foregoing discussion applies to machines operating in work sites to perform material handling operations, such as articulated trucks 10. This system can be used in mines, landfills, quarries, construction sites, road construction sites, forests, farms, or any other location requiring machine operation.

[0061] The disclosed dynamic rollover control system 33 is used to prevent or reduce the likelihood of the machine or a part of the machine (e.g., dump truck body 22) rolling over or tipping over as the machine crosses the work area 100. The dynamic rollover control system 33 can be used with the machine regardless of whether it is operated autonomously, semi-autonomously, or manually. Furthermore, when operated manually, the dynamic rollover control system 33 can provide guidance to the machine operator to reduce the likelihood of a rollover and / or can further include automated controls to prevent or reduce the likelihood of such a rollover event.

[0062] Figure 7 A flowchart illustrating the operation of the dynamic rollover control system 33 is shown. In stage 70, machine characteristics can be stored within or accessed via controller 31. Machine characteristics may include, for example, engine dynamics, power loss feedforward factor characteristics, and machine dimensions. Engine dynamics may include power output based on engine speed and fuel consumption, as well as engine friction losses used in conjunction with the feedforward factor. Machine dimensions may include, for example, the location of the center of gravity 27, and the vertical and horizontal distances from the center of gravity to a location (e.g., 28) on one of the rear wheels 20 for critical speed analysis.

[0063] In stage 71, operating parameters of the dynamic rollover control system 33 can be stored in or accessed through the controller 31. Operating parameters may include, for example, a safety factor used when calculating or applying a desired speed, and logic regarding when and how to apply the service brake 24.

[0064] In stage 72, the effective load within the dump truck body 22 can be determined. In one embodiment, the effective load can be determined by monitoring data from the effective load sensor 42 as described above. In an embodiment where the inertial measurement unit 26 on the dump truck body 22 is monitored to determine the effective load of the dump truck body, data from the dump truck body lifting sensor 41 can be monitored to determine when the dump truck body is emptied. For example, if the lifting angle at which the dump truck body 22 is positioned exceeds a predetermined time threshold, the controller 31 can be used to determine that the dump truck body has been emptied.

[0065] In stage 73, the machine can be operated. In stage 74, the controller 31 can determine the machine's operating characteristics, for example, by receiving data or signals from various sensors operatively associated with the machine. Specifically, the controller 31 can receive ground speed data from the ground speed sensor 35, pitch rate data from the pitch angle sensor 36, pitch angle data from the pitch angle sensor 37, roll angle data from the roll angle sensor 38, yaw rate data from the yaw rate sensor 39 associated with the tilting body 22, yaw rate data from the yaw rate sensor 40 associated with the front frame portion 11, engine speed data from the engine speed sensor 43, transmission speed data from the transmission speed sensor 44, and fuel quantity data from the fuel quantity sensor 45.

[0066] In stage 75, controller 31 may depend on the direction of the ramp on which the machine operates, for example, by determining the critical speed of the machine based on operating characteristics using equations (1)-(3). A safety factor may be added to the calculated critical speed to determine the desired speed for subsequent analysis and control of the machine operation.

[0067] In some embodiments, the controller 31 may utilize only the yaw rate of the dump truck body 22. In other embodiments, the controller 31 may utilize the average of the yaw rate of the front frame portion 11 and the yaw rate of the dump truck body 22. This may be desirable because the current yaw rate of the front frame portion 11 can predict the yaw rate of the dump truck 22 after the front frame portion is positioned in front of the dump truck body.

[0068] In decision phase 76, controller 31 can determine whether the machine's current speed exceeds the desired speed. If the current speed is less than the desired speed, the machine can continue operating. Thus, in decision phase 77, controller 31 can determine, based on data from the dump truck body lifting sensor 41 as described above, whether the load within the dump truck body 22 has been unloaded. If the dump truck body is empty, the articulated truck 10 can continue operating and repeat phases 72-76. If the dump truck body is not yet empty, the articulated truck 10 can continue operating and repeat phases 73-76.

[0069] If the ground speed is greater than the desired speed, in stage 78, controller 31 can reduce the machine's ground speed by controlling the operation of engine 17. To this end, in one embodiment, controller 31 can reduce the fuel supplied to engine 17, thereby reducing the power generated by the engine. The amount of fuel reduction can be determined based on one or more power loss feedforward factors, such as engine friction losses, transmission losses, output transfer gear and shaft losses, rolling resistance losses, scrubbing losses, and gains / losses due to operation on a slope. By analyzing the machine's operating characteristics and power loss feedforward factors, controller 31 can accurately determine the extent to which fuel consumption should be reduced to keep the current speed below the desired speed.

[0070] In some cases, even significantly reducing the fuel supply to engine 17 and relying on power loss feedforward factors may not be sufficient to slow the machine down enough to prevent rollover. Therefore, at decision stage 79, controller 31 can determine whether the machine speed can be sufficiently reduced by controlling the operation of engine 17 alone. If the machine speed can be sufficiently controlled, operation can continue and stages 72 or 73-79 can be repeated. If the machine speed cannot be sufficiently controlled by controlling the operation of engine 17, at stage 80 controller 31 can generate braking command 47 to apply service brake 24, thereby further slowing the machine down. Operation of the machine can then continue and stages 72 or 73-80 can be repeated.

[0071] Various alternatives are also considered. For example, controller 31 can monitor data from the dump truck body lifting sensor 41 to determine when the lifting or lifting angle of the dump truck body 22 changes, such as when the dump truck body descends after dumping. When the angle of the dump truck body 22 changes, controller 31 can ignore the signals from the pitch rate sensor 36 and the yaw rate sensor 39, as well as the dump truck body 22, and rely only on the pitch rate and yaw rate of the front frame section 11, because the yaw rate data of the dump truck body may be inaccurate when the lifting angle of the dump truck body changes. More specifically, the movement of the dump truck body 22 from the raised or dumped position to the lowered position may include movements that may be incorrectly read or interpreted by the inertial measurement unit 26 as part of the pitch rate and yaw rate of the dump truck body. This could occur when the operator completes the dumping operation and drives away to receive the next load.

[0072] It should be understood that the foregoing description provides examples of the disclosed systems and techniques. However, it is conceivable that other embodiments of the invention may be identical in detail to the foregoing examples. All references to the invention or examples thereof are intended to refer to the specific examples discussed herein and are not intended to imply any limitation on the scope of the invention in a more general sense. All distinguishing and derogatory language regarding certain features is intended to indicate a lack of preference for those features, but is not entirely excluded from the scope of the invention unless otherwise stated.

[0073] In the context of describing the invention (especially in the context of the following claims), the terms “a,” “an,” “the,” and “at least one,” and similar designations, should be understood to encompass both singular and plural aspects, unless otherwise stated herein or obviously contradicted by the context. The use of the term “at least one” followed by a list of one or more items (e.g., “at least one of A and B”) should be understood to mean a selection from the listed items (A or B) or any combination of two or more of the listed items (A and B), unless otherwise stated herein or obviously contradicted by the context. Unless otherwise stated, the terms “comprising,” “having,” “including,” and “containing” should be understood as open-ended terms (i.e., meaning “including but not limited to”).

[0074] Unless otherwise stated herein, the enumeration of numerical ranges herein is intended only as a shorthand for individually referring to each individual value falling within that range, and each individual value is incorporated into the specification as if it were individually referenced herein. Unless otherwise stated herein or clearly contradicted by the context, all methods described herein may be performed in any suitable order.

[0075] Therefore, this invention includes all modifications and equivalents of the subject matter recited in the appended claims as permitted by applicable law. Furthermore, unless otherwise stated herein or otherwise clearly contradicted by the context, this invention covers any combination of the foregoing elements in all its possible variations.

Claims

1. A dynamic rollover control system (33) for a machine, comprising: Prime mover (17); Grounding drive mechanisms (14, 20) are operably connected to the prime mover (17); Cargo compartment (22), which is used to carry the payload; A driver's cab (15) operably connected to the cargo box (22); A lift angle sensor (41) associated with the cargo compartment for generating a lift angle signal indicating the lift angle of the cargo compartment; The cab yaw rate sensor (40) on the cab is used to generate a yaw rate signal indicating the yaw rate of the cab; A payload sensor (42) is used to generate a payload signal indicating the payload of the cargo compartment; A yaw rate sensor (39) is used to generate a yaw rate signal indicating the yaw rate of the cargo compartment; A tilt rate sensor (36) is used to generate a tilt rate signal indicating the tilt rate of the cargo compartment; A tilt angle sensor (38) is used to generate a tilt angle signal indicating the tilt angle of the cargo compartment; Ground speed sensor (35), which is used to generate a ground speed signal indicating the current speed of the machine; and Controller (31), which is used for: Access the machine characteristics of the machine; The effective load of the cargo compartment (22) is determined based on the effective load signal; The yaw rate of the cargo box (22) is determined based on the yaw rate signal; The tilt rate of the cargo box (22) is determined based on the tilt rate signal; The tilt angle of the cargo box (22) is determined based on the tilt angle signal; The desired speed of the cargo box (22) is determined based on the machine characteristics, the effective load of the cargo box, the yaw rate of the cargo box, the tilt rate of the cargo box, and the side tilt angle of the cargo box. The current speed of the machine is determined based on the ground speed signal; as well as When the current speed of the machine exceeds the desired speed, a prime mover control signal is generated to control the operation of the prime mover (17) to decelerate the machine, thereby ensuring that the current speed does not exceed the desired speed. The controller (31) is further configured to determine when the lifting angle of the cargo box changes based on the lifting angle signal, determine the yaw rate of the cab based on the cab yaw rate signal, and determine the desired speed based on the cab yaw rate when the lifting angle of the cargo box changes, without using the yaw rate of the cargo box.

2. The dynamic rollover control system (33) according to claim 1, wherein, The prime mover control signal controls the rotational speed of the prime mover (17).

3. The dynamic rollover control system (33) according to claim 2, wherein, The prime mover control signal controls the amount of fuel supplied to the prime mover (17).

4. The dynamic rollover control system (33) according to claim 1, wherein, The prime mover includes an engine, and the prime mover control signal controls the amount of fuel supplied to the engine.

5. The dynamic rollover control system (33) according to any one of claims 1-4, wherein, The controller (31) is further configured to determine the power loss caused by at least one power loss feedforward factor and generate the prime mover control signal based on the power loss caused by the at least one power loss feedforward factor.

6. The dynamic rollover control system (33) according to claim 5 further includes a prime mover speed sensor (43) for generating a prime mover speed signal indicating the speed of the prime mover (17), and the controller (31) is further configured to determine the speed of the prime mover based on the prime mover speed signal and to determine the power loss based on the speed of the prime mover.

7. The dynamic rollover control system (33) according to any one of claims 1-4, wherein the controller is further configured to determine the desired speed based on the average of the yaw rate of the cargo box and the yaw rate of the cab.

8. A machine comprising the system of any one of claims 1-7.

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