Tipper safety systems and methods

Abstract

This specification relates to systems, methods, and apparatus for monitoring the use of a tipper. According to a first aspect of this specification, there is described a computer implemented method for preventing roll over of a tipper vehicle. The method comprises: receiving, from each of a plurality of angle sensors of the tipper vehicle, respective angle measurements of the tipper vehicle while a dump box of the tipper vehicle is in use; receiving, from each of a plurality of load sensors of the tipper vehicle, respective load measurements of the dump box of the tipper vehicle while a dump box of the tipper vehicle is in use; determining, based on the respective angle measurements of the tipper vehicle and the respective load measurements of a dump box of the tipper vehicle, that the tipper vehicle is in an unsafe configuration; and in response to determining that the tipper vehicle is in an unsafe configuration, controlling the position of the dump box of the tipper vehicle.

Description

[0001] Tipper Safety Systems and Methods

[0002] Technical Field

[0003] This specification relates to systems, methods, and apparatus for monitoring the use of a tipper. In particular, this specification describes systems, methods, and apparatus for preventing the rollover of a tipper during discharge of a payload.

[0004] Background

[0005] Tippers are vehicles with a rear container that can be raised (tipped) to discharge a payload, typically pivoting about the rearmost corner. The rear container is raised by a ram controlled by a driver / operator.

[0006] Tippers are susceptible to roll over incidents as the body is raised and the centre of gravity (COG) height increases. Any lean of the vehicle moves the overall COG laterally, decreasing stability. If the COG gravity line goes outside of the tyre contact point, then lateral roll-over will begin. Chassis angle systems are available that measure chassis roll angle and give operators warnings when it is above safe limits (as defined by the software). These systems typically use a single chassis roll angle measurement, often (but not always) near the hydraulic ram mounting point on the chassis.

[0007] Tippers are also susceptible to collision accidents as the body is raised, which can be on fixed obstructions (e.g., buildings or bridges) or less obvious, but equally dangerous, power cables. Commercial systems are available for obstruction proximity warning or cable proximity detection. These systems will give the operator a warning when an object is detected.

[0008] Furthermore, tippers are also susceptible to non-standard use by operators which may increase risk of roll-over or other unsafe conditions. These may include, for example, driving the tipper vehicle when tipped, e.g., in an effort to loosen the load, and / or raising body to end point of the ram repeatedly to induce a shock load / shoch loads to loosen the payload, potentially destabilising vehicle and damaging equipment.

[0009] Summary

[0010] According to a first aspect of this specification, there is described a computer implemented method for preventing roll over of a tipper vehicle. The method comprises: receiving, from each of a plurality of angle sensors of the tipper vehicle, respective angle measurements of the tipper vehicle while a dump box of the tipper vehicle is in use; receiving, from each of a plurality of load sensors of the tipper vehicle, respective load measurements of the dump box of the tipper vehicle while a dump box of the tipper vehicle is in use; determining, based on the respective angle measurements of the tipper vehicle and the respective load measurements of a dump box of the tipper vehicle, that the tipper vehicle is in an unsafe configuration; and in response to determining that the tipper vehicle is in an unsafe configuration, controlling the position of the dump box of the tipper vehicle.

[0011] Determining that the tipper vehicle is in an unsafe configuration may comprise determining that the tipper vehicle is in an unstable configuration and / or that that the tipper vehicle will enter an unstable configuration.

[0012] Determining that the tipper vehicle is in an unsafe configuration may comprise: determining a stability parameter value for each of the plurality of times based on the respective angle measurements of the tipper vehicle and the respective load measurements of the dump box; comparing the stability parameter value to one or more stability parameter thresholds; and determining that the tipper vehicle is in an unsafe configuration in response to the stability parameter value exceeding one or more of the threshold values.

[0013] Controlling the position of the dump box of the tipper vehicle may comprise one or more of: preventing the dump box being raised further; restricting the rate at which the dump box can be raised; and / or lowering the dump box to a predefined position.

[0014] Determining that the tipper vehicle is in an unsafe configuration may comprise: determining, based on the respective angle measurements of the tipper vehicle and the respective load measurements of a dump box, a current centre of gravity of the dump box; and comparing a lateral position of the centre of gravity of the dump box to one or more threshold positions.

[0015] The plurality of angle sensors of the tipper vehicle may each be located at one of a plurality of locations on the tipper vehicle. The plurality of locations comprises a dump box ram location and a dump box pivot location. Determining that the tipper vehicle is in an unsafe configuration may comprise: determining, based on the respective angle measurements at a plurality of locations on the tipper vehicle, a tipper vehicle roll angle and / or a dump box roll angle. Determining that the tipper vehicle is in an unsafe configuration may comprise: determining, based on the respective angle measurements at a plurality of locations on the tipper vehicle, a tipper vehicle twist angle.

[0016] The plurality of load sensors of the tipper vehicle may each be located at one of a plurality of load sensor locations, the plurality of load sensor locations comprising a dump box ram location and two sides of a dump box pivot location.

[0017] The angle measurements of the tipper vehicle may comprise an alignment angle between a cab of the tipper vehicle and a trailer of the tipper vehicle.

[0018] The method may further comprise: receiving, from a plurality of wind pressure sensors located on either side of the dump box, respective wind pressure measurements; and determining, based on the respective wind pressure measurements, a net wind force on the dump box, wherein determining that the tipper vehicle is in an unsafe configuration is further based on the net wind force on the dump box.

[0019] The method may further comprise: receiving, from a plurality of object detection sensors monitoring a space around the dump box, respective object detection data indicative of the presence or absence of an object in the space around the dump box, wherein determining that the tipper vehicle is in an unsafe configuration is further based on the respective object detection data.

[0020] The method may further comprise: receiving, from a ram extension sensor, an extension value of a ram of the tipper vehicle; limiting a maximum ram extension speed based on a comparison of the extension value of the ram to the maximum extension value of the ram, wherein the maximum ram extension speed decreases as the extension value of the ram approaches the maximum extension.

[0021] According to a further aspect of this specification, there is described a safety system for a tipper vehicle, the safety system comprising: a plurality of angle sensors; a plurality of load cells; one or more processors; and a memory, the memory storing computer readable instructions that, when executed by the one or more processors, causes the system to perform any one or more of the methods disclosed herein.

[0022] The safety system may further comprise one or more wind pressure sensors. The safety system may further comprise one or more object detection sensors. The safety system may further comprise a ram extension sensor. According to a further aspect of this specification, there is described a tipper vehicle comprising a safety system as described herein.

[0023] According to a further aspect of this specification, there is described a computer program product comprising computer readable instructions that, when executed by a computer, cause the computer to perform any one or more of the methods described herein.

[0024] Brief Description of the Drawings

[0025] FIG. 1A shows a side view of an example of a tipper vehicle with its dump box lowered;

[0026] FIG. IB shows a side view of an example of a tipper vehicle with its dump box raised;

[0027] FIG. 1C shows a top view of an example of a tipper vehicle;

[0028] FIG. 2 shows a schematic example of a tipper safety system;

[0029] FIGs. 3A-D show examples of a risk of roll-over parameter configurations of a tipper truck;

[0030] FIG. 4 shows an example of a calculation of an overall safety score;

[0031] FIG. 5 shows a flow diagram of an example safety method for a tipper vehicle; and FIG. 6 shows a schematic overview of a computer system for use in performing any of the methods described herein.

[0032] Detailed Description

[0033] This specification describes a safety system / method for tipper trucks (also referred to herein as "tipper vehicles") that reduces the incidence of rollover events when a payload is being discharged from a dump box of the tipper truck. The systems / methods are based on continuously monitoring roll angles of the tipper truck and loads on load cells at multiple locations in the tipper truck and controlling the raising / lowering of the dump box of tipper truck based on these data.

[0034] FIG. 1A shows a side view of an example of a tipper vehicle 100 with its dump box 102 lowered. The tipper vehicle 100 comprises a dump box 102 (also referred to herein as a "rear container" or "body") for containing a payload, the dump box 102 positioned on a dumb box frame 104. Collectively, the dump box 102 and dump box frame 104 may, in some examples, be referred to as a trailer. The tipper vehicle 100 further comprises a ram 106 configured to raise one end of the dump box 102, as shown in FIG. IB. The tipper vehicle 100 further comprises a cab 108 (also referred to herein as a "tractor") from which a driver may manoeuvre the tipper vehicle 100. The dump box 102 is a container for holding a payload, such as aggregate, sand, asphalt, or the like. The dump box 102 may be open at the top or fully enclosed. In some examples, the inside of the dump box 102 forms a continuous space for containing the payload. In other examples, the dump box 102 may be partitioned internally into a plurality of partitions / compartments. This can allow partial deliveries to be made. The rearmost compartments are unloaded each time, resulting in the remaining payload being left higher up the dump box 102 and thus raising the centre of gravity (COG) of the dump box 102 when raised.

[0035] A rear end of the dump box 102 (i.e., the end of the dump box furthest from the cab) may, in some examples, comprise a hatch 110 (also referred to herein as a "door"). The hatch 110 can be locked in position to retain the payload in the dump box 102. When in use, i.e., when the tipper is being raised / tipped to discharge the payload, the hatch may be unlocked to allow the payload to flow out of the dump box 102. For example, the hatch may be hinged 112 along a top edge of the hatch, such that the hatch 110 opens under gravity when the dump box 102 is tipped or when the payload pushes against it. In some examples, the hatch 110 can be unlocked manually. Alternatively or additionally, the hatch 110 may be unlocked automatically, for example when the ram 106 is being raised.

[0036] The dump box 102 may be attached to the dump box frame 104 by a pivot 114 at or near the bottom rear of the dump box 102. When the ram 106 is raised, the dump box rotates around the pivot 114 into a tipping position in which the payload of the dump box 102 flows out of the dump box 102 under gravity.

[0037] The dump box frame 104 comprises a plurality of load cells 116A-B for measuring the load on the dump frame 104 from the dump box 102 at a plurality of locations. In the example shown, one load cell 116A is positioned at / under the ram 106 and two load cells are positioned under the pivot 114 of the dump box 102, e.g., one arranged on each side of the dump box, as shown in FIG. 1C. The load cells 116 may continuously measure a respective load at their respective locations caused by the dump box 102, e.g., measure the load at a predefined frequency (e.g., 1Hz, 10Hz or the like).

[0038] A plurality of angle sensors 118A-E (also referred to as "tilt sensors" or "inclinometers") are distributed throughout the tipper vehicle 100. For example, one or more angle sensors 118A-B may be arranged at the rear of the trailer, e.g., on the dump box 102 (e.g., angle sensor 118A) and / or on the dump box frame 104 (angle sensor 118B). One or more angle sensors 118B may be arranged at the front of the trailer, e.g., on the dump box 102 (e.g., angle sensor 118C) and / or on the dump box frame 104 (e.g., angle sensor 118D). One or more angle sensors 118E may be arranged on the cab 108. Each angle sensor 118A-C measures a respective one or more rotation angles of the tipper truck at its respective location in the tipper truck. The rotation angles include roll angles, i.e., angles around a longitudinal axis (the roll axis) aligned with the tipper truck. Since the tipper truck 100 is not perfectly rigid, the tipper truck 100 may, in general, have different roll angles at different positions throughout. In some examples, the angle measurements further include pitch angles (i.e., angle measurements about a horizontal axis perpendicular to the roll axis) and yaw angles (i.e., angle measurements about a vertical axis). The angle sensors 118 may continuously measure one or more respective angles at their respective locations, e.g., measure the one or more angles at a predefined frequency (e.g., 1Hz, 10Hz or the like).

[0039] In some examples, the cab 108 is fixed relative to the dump box frame 104. In some examples, the cab 108 and the dump box frame 104 are connected via an articulated connection such that the angle between the cab and the dump box frame 104 can vary. In such examples, the angle sensors 118 may further comprise one or more angle sensors for measuring an alignment between the cab 108 and the trailer (also referred to herein as a "tractor-trailer alignment" or an "articulation angle").

[0040] In some examples, the dump box 102 further comprises one or more wind pressure sensors 120 on either side face of the dump box 102 (i.e., on the left and right vertical faces of the dump box 102). The wind pressure sensors each measure a respective wind pressure on a side of the dump box. In some examples, a wind pressure sensor 120 is located at a top front on each side of the dump box 102 so that the wind speed is measured at the highest point of the dump box when raised. In some examples, a plurality of wind pressure sensor 120 are distributed over each side face of the dump box 102. Wind speed increases logarithmically with height - so a relatively low wind speed at ground level becomes much greater as the height from ground increases. Therefore, wind pressure on the dump box 102 can be a significant roll-over force.

[0041] In some examples, the dump box 102 further comprises an object / collision detection system 122 configured to detect objects, such as people and / or cables, within a predefined area around the tipper vehicle 100. The predefined area may include an exclusion area around at least a part of the tipper truck 100 that is required to be free from objects when the dump box 102 is in use. Commercially available systems can be fitted to the tipper vehicle 100 at strategic position(s) to detect hard obstacles and / or power cables.

[0042] In some implementations, the ram 106 comprises an extension sensor (not shown) configured to measure an extension of the ram 106. The ram extension may comprise an absolute measurement (e.g., a distance that the ram is extended from the fully lowered position) and / or a relative measurement (e.g., a fraction / percentage of the full extension of the ram).

[0043] When in use, i.e., when the dump box is being raised and / or is in a raised position, the sensors (i.e., the load sensors 116, the angle sensors 118 and, if present, the wind pressure sensors 120 and object detection system 122) transmit respective sensor data (also referred to herein as "measurement data") to a control system (not shown) of the tipper vehicle 100. Based on the measurement data, the control system determines if the tipper vehicle is in an unsafe configuration (e.g., is unstable and / or will be unstable at a future time) and controls the tipping of the dump box 102 based on the determination, e.g., controls the ram 106. Examples of the operations performed by the control system are described in further detail herein with respect to at least FIGs. 2 and 3.

[0044] FIG. IB shows a side view of an example of a tipper vehicle 100 with its dump box 102 raised. The features of FIG. IB generally correspond to those of FIG. 1A. In use, the ram 106 extends, raising one end of the dump box 102, and causing the dump box to rotate abouts its pivot 114. When the hatch 110 is unlocked, the payload of the dump box 102 then flows out of the dump box 102 under gravity.

[0045] The ram 106 is, in some examples, a hydraulic ram. Alternatively, the ram 106 can be an electric ram. Other examples of ram types will be familiar to those skilled in the art. In the example shown, the ram 106 is positioned at the front of the dump box 102. However, in some examples, the ram 106 may be an underfloor ram, or any other ram type suitable for raising the dump box 102.

[0046] While the ram 106 is being raised, and while it remains at least partially extended, the angle sensors 118 and load sensors 116 are used to continuously monitor angles of rotation and loads respectively at a plurality of positions in the tipper vehicle. If present the wind pressure sensors 120 and / or object detection sensors are also used to continuously monitor the wind pressure and area around the tipper truck 100 respectively while the ram is raised or being raised. In some embodiments, the extension speed of the ram 106 may be controlled based on the extension length of the ram 106. As the ram 106 reaches full extension, the extension speed of the ram 106 (also referred to as the "speed of lift" of the ram 106) is progressively slowed. In this manner, the deceleration when the ram reaches full extension can be reduced, which in turn reduces shock loads to the system. The rate of lift speed reduction as a function of the ram extension can be programmed into the system. For example, the rate of lift speed reduction may be based on a look-up table that maps ranges of ram extensions to corresponding lift speed reductions. It will be appreciated that this ram speed adjustment aspect of the specification may be implemented independently of the other safety systems and methods described herein.

[0047] FIG. 1C shows a top view of an example of a tipper vehicle 100. The features of FIG. 1C generally correspond to those of FIGs. 1A-B. The dump box 102 is shown in the lowered location, and enclosed from the top, e.g., with a roof.

[0048] In this example, the tipper truck 100 has three load cells 116A-C. One load cell 116A is positioned at the ram 106 location. Two load cells 116B, 116C are positioned at the pivot 114 location, one load cell on the left side of the pivot 116B and one load cell 116C on the right side of the pivot. This triangular arrangement of load cells can assist in the determination of a centre of gravity (COG) location of the dump box 102.

[0049] In the example shown, the angle sensors 118A, 118C of the dump box 102 are shown as being located along the central line of the roof of the dump box 102. However, the angle sensors 118A, 118C may alternatively be located on the side walls of the dump box, e.g., in pairs either side of the dump box 102.

[0050] The example shown also includes one or more articulation sensors 124 for determining an articulation angle between the cab 108 and the trailer of the tipper vehicle 100. The articulation sensors 124 may determine a heading of the cab 108 and a heading of the trailer, for example using GPS and / or compasses, and take the difference between them to determine the articulation angle of the tipper vehicle.

[0051] FIG. 2 shows a schematic example of a tipper safety system 200. The system 200 comprises a plurality of angle sensors 202 and a plurality of load cells 204 arranged at plurality of positions on the tipper vehicle, e.g., as shown in FIGs. 1A-C. The system 200 further comprises a COG subsystem 206 configured to determine a COG of the dump box based on angle measurements from at least some of the angle sensors 202 and load measurements from the load cells 204. The system 200 further comprises a safety parameter subsystem 208 configured to determine one or more safety parameter scores (also referred to herein as "stability factor scores") from the angle measurements, load measurements and / or, if present, the COG location. The system 200 further comprises a dump box control subsystem 210, configured to control the dump box and / or restrict control of the dump box based on the one or more safety parameter scores determined by the safety parameter subsystem 208.

[0052] In some examples, the system 200 further comprises one or more wind pressure sensors 21 and / or an object detection subsystem 214, the outputs of which may be used by the safety parameter subsystem 208 to determine one or more of the safety parameter scores.

[0053] In some examples, the system 200 further comprises an object / cable detection subsystem 214, the outputs of which may be used by the safety parameter subsystem 208 to determine one or more of the safety parameter scores.

[0054] In some examples, the system 200 further comprises one or more ram extension sensors 216 for measuring an extension of the ram, the output(s) of which may be used by the dump box control subsystem 210 to control a maximum allowed ram speed.

[0055] The COG subsystem 206 configured to continuously (e.g., at a fixed frequency) determine at a COG position of the dump box, e.g., a vertical, longitudinal and / or lateral COG position, while the dump box is in use. Any method known in the art for determining COG positions may be used by the COG subsystem 206.

[0056] In some examples, the COG subsystem 206 is configured to determine at a COG position of the dump box without a load present and the contribution of the empty dump box to the load cell readings, i.e., in order to provide a tare. For a given dump box raising angle, the longitudinal position of the COG (i.e., the position on the front- back axis of the tipper vehicle) can be calculated from the resting COG position of the dump box using trigonometry. Furthermore, for a given angle, the contribution of the empty dump box to the load cell readings can be determined based on the load cell locations and the mass of the empty dump box, e.g., by using a moment calculation. In some examples, the COG subsystem 206 is configured to determine at a COG position of the dump box with a load present. The calculation of the mass / COG of the dump box plus the payload may, for example, be based on trigonometry and / or moment calculations using the continuous load cell readings to calculate a total mass of the dump box and payload, Mt, and the longitudinal position of its COG.

[0057] The height of the COG may be determined indirectly by assuming that that the payload CIG is half-way up the dump box, i.e., lies in a plane halfway up the dump box when flat. The height of the COG can then be determined based on the longitudinal position of the COG and the angle that the dump box has been raised. Alternatively, the height of the COG may be determined based on a lateral force distribution (left to right), assuming the payload is equally distributed.

[0058] To calculates the mass of the payload, MP, and its longitudinal COG location, the dump box tare values can be subtracted from the load cell measurements, and the trigonometry / moment calculations for the overall COG can be repeated on the remaining forces.

[0059] The dump box pivot is typically the rear of the trailer, and the ram is somewhere at or close to the front of the trailer. The pivot is effectively a line, but the ram acts on a single point. With the stiffness of the body not being infinite (of course) it is possible for the body to be twisted and / or moved sideways at the front relative to the rear.

[0060] In the normal (e.g., straight, no twist, and an evenly distributed payload) the COG will stay roughly central. If the dump box moves laterally (either through misalignment or twist) and / or the payload shifts to one side (for example if one side discharges and the other side is stuck) this will be registered as a difference in the load side to side at the rear load cells, and the lateral COG will shift to the side.

[0061] In some examples, the COG subsystem 206 is configured to determine at a lateral COG position / movement. There are several ways that the COG of the dump box can move laterally. For example, the payload may shift inside the dump box. The result of such a shift will be a difference in loads measured by load cells on either side of the dump box. As another example, the dump box may have a twist with respect to the dump box frame. Such a twist will result in a difference in loads measured by load cells on either side of the dump box, as well as a difference in roll angles measured by the angle sensors for the dump box and the dump box frame. As another example, the whole trailer (i.e., dump box and dump box frame) may have a roll angle. Such a twist will result in a difference in loads measured by load cells on either side of the dump box, as well as a non-zero roll angle measured by angle sensors on both the dump box and dump box frame. Combinations of these three examples may also result in a lateral shift of the COG.

[0062] Whatever the cause, the total lateral COG shift can be determined from the continuously calculated mass (i.e., from the load measurements) and from the COG vertical position (determined as described above). In some examples, the effect of each cause of the COG shift may be determined. The COG subsystem 206 can use the continuous mass measurements, COG calculation and the overall roll angle to calculate lateral shift contribution from the roll angle. Similarly, the COG subsystem 206 can use the continuous mass measurements, COG calculation and the twist angle to calculate lateral shift contribution from the twist of the vehicle. The remaining lateral COG shift contribution is from payload.

[0063] The wind pressure sensors 212 may determine a "delta pressure" (i.e., a difference in wind pressure / wind pressure difference) from left to right, or vice versa, measured at single or multiple points on each side of the tipper vehicle. This continuous data input can be converted into an overturning force, for example for a single sensor on each side by multiplying the "delta pressure" by the side view area of the dump box / tipper vehicle. In examples where multiple wind pressure sensors are present on either side of the dump box, the overturning force may be based on an average wind pressure, e.g., the average wind pressure difference multiplied by the side view area of the dump box / tipper vehicle. Alternatively, in examples where multiple wind pressure sensors are present on either side of the dump box, the overturning force may be determined by multiplying each wind pressure difference by the respective area associated with the corresponding sensors (e.g., the sensor pair from which the difference was determined). Alternatively, a computational fluid dynamics-based analysis can be used to calculate roll over moment versus delta pressure vs tip angle, and that relationship used to convert the pressure into an overturning force.

[0064] In some examples, the methods of determining the overturning force can be adjusted to account for fluid dynamical properties of the dump box, e.g., to allow for the fact that pressure tends to dissipate at edges so effective area of side is lower than the true area. In such examples, an effective area of the dump box / tipper truck can be used that is different from the actual value. The effect area may, for example, be based on empirical values or computational fluid dynamics calculations. Based on the lateral COG and, if present, the wind force of the dump box, a risk of roll-over (RoRO) parameter is, in some examples, determined by the safety parameter subsystem 208. FIGs. 3A-D shows examples of increasing RoRO parameter values. The RoRO parameter is calculated using the calculated overall weight, and COG vertical lateral position, and the wind moment. The moment around a point 302, X, within the wheelbase of the tipper truck 300 is a measure of the RoRO parameter, e.g., a point at the centre of the wheelbase.

[0065] FIG. 3A shows an example of a zero RoRO parameter configuration of the tipper truck 300. In this example, the lateral COG 304 of the tipper truck 300 is positioned directly above the point X 302, and no net wind force / moment is on the dump truck. Consequently, the RoRO parameter is zero, i.e. there is no risk of a rollover event.

[0066] FIG. 3B shows an example of a low RoRO parameter configuration of the tipper truck 300. In this example, the lateral COG 304 of the tipper truck 300 shifted laterally with respect to the point X 302 (e.g., due to a roll and / or twist of the tipper vehicle 300 / dump box, and / or a payload shift within the dump box) but remains within the wheelbase of the tipper truck 300. No net wind force / moment is on the dump truck. Consequently, the RoRO parameter is low, i.e., there is a low risk of a rollover event.

[0067] FIG. 3C shows an example of a high RoRO parameter configuration of the tipper truck 300. In this example, the lateral COG 304 of the tipper truck 300 shifted laterally with respect to the point X 302 (e.g., due to a roll and / or twist of the tipper vehicle 300 / dump box, and / or a payload shift within the dump box) and falls outside wheelbase of the tipper truck 300. No net wind force / moment is on the dump truck. Consequently, the RoRO parameter is high, i.e., there is a high risk of a rollover event.

[0068] FIG. 3D shows an example of a maximum RoRO parameter configuration of the tipper truck 300. In this example, the lateral COG 304 of the tipper truck 300 shifted laterally with respect to the point X 302 (e.g., due to a roll and / or twist of the tipper vehicle 300 / dump box, and / or a payload shift within the dump box) and falls outside wheelbase of the tipper truck 300. A net wind force / moment 306 is also applied to the dump truck, acting in the same direction as the COG moment. Consequently, the RoRO parameter is at a maximum, i.e., there is a very high risk of a rollover event.

[0069] Returning to FIG. 2, the safety parameter subsystem 208 is, in some implementations, configured to determine one or more safety parameter scores, Si, each relating to a different aspect of the tipper vehicle, e.g., one or more vehicle and / or body roll angles, a vehicle / body twist angle, a tractor-trailer articulation angle, the RoRO parameter (as discussed above), and / or the presence or absence of objects in the exclusion zone around the tipper vehicle. In some examples, the one or more safety parameter scores further comprise scores relating to time derivatives of aspects of the tipper vehicle (referred to herein as "rate of change factors"), e.g., time derivatives of the roll angle(s), time derivatives of the twist angle(s), time derivatives of the tractor-trailer articulation angle, time derivatives of the RoRO parameter, and / or the time derivatives of object positions around the tipper vehicle.

[0070] Each safety parameter score may, for example, be a continuous value taken from the same range, e.g., a score between zero and two, with zero indicating a completely safe configuration, one indicating a marginal safe configuration and two indicating a completely unsafe configuration. Alternatively, each safety parameter score may take a discrete value in a range of values, e.g., an integer between zero and ten.

[0071] The safety parameter subsystem 208 may compare each safety parameter score to one or more respective threshold values to determine if the tipper vehicle is in an unsafe configuration. The thresholds may in general be different for each aspect. Alternatively, for simplicity, the thresholds may be the same for each aspect.

[0072] While the threshold-based method can be used to identify unsafe / unstable aspects of the tipper vehicle configuration, the tipper vehicle may be in unsafe configuration without any of the individual thresholds being exceeded, i.e., collectively the safety parameter scores indicate an unsafe configuration without any individual safety parameter threshold being exceeded. To account for this, the safety parameter subsystem 208 is, in some implementations, configured to determine an overall safety factor, S, based on the plurality of safety parameter scores.

[0073] An example of the calculation of an overall safety score is shown in FIG. 4. In this example, the overall safety factor is based on the current level for a vehicle / body roll, a vehicle / body twist, a RoRO, and the output of an object detection system, as well as their corresponding rates of change. The safety parameter scores take, in this example, a continuous value between zero and two. The threshold for any individual safety parameter score is, for example, 1.8, i.e., none of the individual safety parameter scores exceed the threshold and is 2.0 for the overall safety parameter score. In the example shown, the overall safety score, S, is determined by first determining a combined safety parameter score for each aspect by summing the safety parameter score for that aspect and the corresponding rate of change factor for the aspect. The overall safety factor may be given by the sum of the highest safety parameter score (in this example, the combined LROS score of 1.5) and an average of the other combined safety parameter scores (in this example, an average of the combined vehicle / body roll, vehicle / body twist and obstruction scores, which comes to 0.5). The overall safety parameter value is thus, in this example, equal to 2.0. This overall safety parameter is equal to the threshold for the overall safety parameter score, and thus the tipper vehicle is determined to be in an unsafe configuration.

[0074] Returning to FIG. 2, the dump box control subsystem 210 uses the one or more safety parameter scores and / or the overall safety parameter score to determine how to control the dump box. If the one or more safety parameter scores and / or the overall safety parameter score all indicate that the tipper vehicle is in a safe configuration, then the dump box control subsystem 210 imposes no restrictions on the control of the dump box by an operator. If, for example, one or more of the safety parameter scores or the overall safety parameter score indicate a marginal stability / safety for the tipper vehicle configuration, the dump box control subsystem 210 may restrict the maximum speed at which the dump box may be raised. Alternatively, if one or more of the safety parameter scores or the overall safety parameter score indicate a marginal stability / safety for the tipper vehicle configuration, the dump box control subsystem 210 may prevent the dump box being raised further, but still allow an operator to lower the dump box. If one or more of the safety parameter scores or the overall safety parameter score indicate that the tipper vehicle is in an unsafe configuration, then the dump box control subsystem 210 may cause the dump box to be lowered to a predefined position, e.g., the resting position.

[0075] In some examples, the dump box control subsystem 210 may take different actions depending on which of the one or more safety parameter scores are indicated as being in an unsafe / marginal configuration, or for different combinations of unsafe / marginal scores. For example, if a safety parameter score, e.g., the roll angle parameter, indicates a marginal safety, but the corresponding rate of change of the parameter is safe, the dump box control subsystem 210 may take a first action, e.g., restricting the maximum speed at which the dump box may be raised. However, if the safety parameter score and the corresponding rate of change of the parameter both indicate a marginal safety, the dump box control subsystem 210 may take a second action, e.g., preventing the dump box being raised further, but still allowing an operator to lower the dump box. Many other examples are possible.

[0076] In some implementations, the dump box control subsystem 210 controls the ram based at least in part on the ram extension data collected by the ram extension sensors 216. The dump box control subsystem 210 may limit the maximum raising speed of the ram as the ram approaches maximum extension in order to prevent shocks to the dump box caused by an abrupt deceleration of the dump box as the ram reaches maximum extension. Instead, by gradually reducing the maximum speed of the ram extension as full extension is approached, the dump box is bought smoothly to its maximum incline.

[0077] In some examples, at least some of the collected / calculated data may be recorded by system 200 for analysis and recommendations for operator training and / or modified safety levels. Alternatively or additionally, data can be monitored in real-time by remote operators / supervisors to provide safety oversight and / or guidance as required.

[0078] FIG. 5 shows a flow diagram of an example safety method 500 for a tipper vehicle. For convenience, the method is described as being performed by a system, such as one or more on-board computer systems of a tipper truck.

[0079] At operation 502, the system receives respective angle measurements of the tipper vehicle from a plurality of angle sensors of the tipper vehicle while the dump box of the tipper vehicle is in use (i.e., while the dump box is being raised / tipped, and / or is in a raised / tipped position).

[0080] The plurality of angle sensors may be arranged a plurality of locations in the tipper truck, e.g., one or more at each of a plurality of locations on the dump box (such as the ram location and / or pivot location), one or more on the tipper truck cab, and / or one or more at each of a plurality of locations on the dump box frame. Each sensor may send a stream of measurements to the system, e.g., a sequence of angle measurements, each angle measurement taken at a time in a sequence of times (such as at a predefined frequency). The angle measurements may comprise roll angles at a plurality of locations in the tipper vehicle. These may be used to determine twist and roll angles of the tipper vehicle.

[0081] At operation 504, the system receives respective load measurements of the dump box of the tipper vehicle from a plurality of load sensors of the tipper vehicle while a dump box of the tipper vehicle is in use (i.e., while the dump box is being raised / tipped, and / or is in a raised / tipped position). The load cells each measure a respective load from the dump box.

[0082] The plurality of angle sensors may be arranged a plurality of locations in the tipper truck, e.g., one or more at each of a plurality of locations on the dump box frame (such as one at the ram location and two at the pivot location). Each sensor may send a stream of measurements to the system, e.g., a sequence of load measurements, each load measurement taken at a time in a sequence of times (such as at a predefined frequency). The sequence of measurements may correspond to the sequence of angle measurements, e.g., be taken at the same sequence of times / frequency. Alternatively, the load measurements may be taken at different times (e.g., offset from the angle measurements ) / at a different frequency.

[0083] In some implementations, the system further receives, from a plurality of wind pressure sensors located on either side of the dump box (e.g., one or more wind pressures sensors on each side of the dump box), respective wind pressure measurements. The wind pressure measurements may be received as a sequence of wind pressure measurements while the dump box is in use, e.g., at a plurality of times forming a sequence of times / at a predefined frequency. The system may determine a net wind force on the dump box based on differences between the wind pressure on each side of the dump box.

[0084] In some implementations, the system further receives, from one or more object detection systems monitoring the space around the tipper vehicle, respective object detection data indicative of the presence or absence of an object in the space around the dump box (e.g., in an exclusion area around the dump box). The object detection data may be received intermittently, i.e., only when an object is detected in space around the dump box. Alternatively, the object detection data may be received as a stream of data, i.e., at a sequence of times / at a predetermined frequency, with the object detection data indicating the presence or absence of an object in the area around the tipper truck.

[0085] At operation 506, the system determines whether the tipper vehicle is in an unsafe configuration based at least in part on the received respective load measurements and the respective angle measurements. If the system determines that the tipper is in an unsafe configuration, the system proceeds to operation 508. If the system determines that the tipper is not in an unsafe configuration, the system returns to operation 502, and receives senor data for a subsequent time, and the dump box remains under the control of an operator, i.e., the operator is free to raise and / or lower the dump box.

[0086] Determining that the tipper vehicle is in an unsafe configuration may comprise determining that the tipper vehicle is currently in an unstable configuration, e.g., that the tipper is close to becoming unstable or has become unstable, and / or that there are obstacles in the exclusion zone of the tipper vehicle. Alternatively or additionally, determining that the tipper vehicle is in an unsafe configuration may comprise determining that the tipper vehicle will enter an unstable configuration at a future point in time, e.g., that a predicted future configuration of the tipper truck that is, for example, based on the current configuration of the tipper truck and time derivatives of one or more parameters of the configuration of the tipper truck, is unstable or close to unstable.

[0087] In some implementations, determining that the tipper vehicle is in an unsafe configuration comprises determining one or more roll angles for the tipper truck based on the plurality of angle measurements, e.g., an overall roll angle and / or a roll angle of sub-portions of the tipper vehicle. In some implementations, determining that the tipper vehicle is in an unsafe configuration comprises determining one or more twist angles of the tipper truck, e.g., a difference between roll angles of the tipper vehicle at different locations. In some implementations, determining that the tipper vehicle is in an unsafe configuration comprises determining an articulation angle between a cab / tactor of the tipper vehicle and a trailer of the tipper vehicle.

[0088] In some implementations, determining that the tipper vehicle is in an unsafe configuration comprises determining a current centre of gravity (COG) position for the dump box based on the load measurements and the angle measurements. The current centre of gravity position may be compared to one or more predefined positions to determine whether the tipper is in an unstable configuration or close to becoming in an unstable position. For example, the horizontal / lateral position of the COG may be compared to wheel positions of the tipper vehicle. If the horizontal / lateral position of the COG is outside the wheelbase of the tipper vehicle, or within a threshold distance of being outside the wheelbase, then the system determines that the tipper truck is in an unstable configuration.

[0089] In some implementations, the determining that the tipper vehicle is in an unsafe configuration is based at least in part on time derivatives of parameters of the vehicle configuration, e.g., time derivatives of the angle measurements, load measurements, etc. The time derivative may, for example, be calculated numerically from the angle measurements and / or load measurements.

[0090] In some implementations, if one or more of the time derivatives of the parameters of the vehicle configuration are above a respective threshold, the system may determine that the tipper vehicle is in an unsafe configuration. Alternatively or additionally, the time derivatives of the parameters of the vehicle configuration and the current values of the parameters of the vehicle configuration may be used to estimate one or more future configurations of the tipper vehicle, e.g., by using a Taylor expansion of the parameters. An estimate of the configuration at one or more future times may be obtained, and compared to the same thresholds as the current configuration to determine if the tipper vehicle will become unstable at a future time.

[0091] In some implementations, the system calculates a plurality of safety parameter values for the tipper vehicle, each corresponding to a respective aspect of the tipper truck, as described in relation to FIG. 2.

[0092] In some implementations, the system calculates an overall safety parameter value for the tipper vehicle based on the plurality of safety parameter values, as described in relation to FIG. 2.

[0093] At operation 505, the system controls the position of the dump box in response to determining that the tipper is in an unsafe configuration. In some examples, the system removes control of the dump box from the operator, e.g., the system takes over control of the dump box, for example by lowering it to a predefined position. Alternatively or additionally, the system limits the control of the dump box by the operator, e.g., prevents the operator from raising the dump box further, but allowing the operator to lower the dump box.

[0094] In some examples, the system controls the dump box based on the safety factor calculated at operation 306. Based on the overall safety factor and / or the individual safety factors, with a time filter to prevent momentary spiking in some examples, the system may control the dump box in one of the following ways: (i) allow the dump box to continue tipping and respond fully to operator commands (e.g., if the overall safety factor indicates a safe configuration); (ii) cease further increase in tipping angle of the dump box and respond only to downward commands (e.g., if a future configuration of the tipper vehicle is determined to be unsafe if the current rate of raising the tipper is maintained); (iii) cease responding to operator commands and lower the dump box to safe position (e.g., continuously calculated) or to default safe position (e.g., at or near fully home); or (iv) limit the maximum speed at which the dump box may be raised and / or lowered.

[0095] FIG. 6 shows a schematic overview of a computer system for use in performing any of the methods described herein. The system / apparatus 600 may form at least a part of a concrete mixer, e.g. part of an ECU of a concrete mixer.

[0096] The apparatus (or system) 600 comprises one or more processors 602. The one or more processors control operation of other components of the system / apparatus 600. The one or more processors 602 may, for example, comprise a general-purpose processor. The one or more processors 602 may be a single core device or a multiple core device. The one or more processors 602 may comprise a Central Processing Unit (CPU) or a graphical processing unit (GPU). Alternatively, the one or more processors 602 may comprise specialised processing hardware, for instance a RISC processor or programmable hardware with embedded firmware. Multiple processors may be included.

[0097] The system / apparatus comprises a working or volatile memory 604. The one or more processors may access the volatile memory 604 in order to process data and may control the storage of data in memory. The volatile memory 604 may comprise RAM of any type, for example, Static RAM (SRAM) or Dynamic RAM (DRAM), or it may comprise Flash memory, such as an SD-Card.

[0098] The system / apparatus comprises a non-volatile memory 606. The non-volatile memory 606 stores a set of operation instructions 608 for controlling the operation of the processors 602 in the form of computer readable instructions. The non-volatile memory 606 may be a memory of any kind such as a Read Only Memory (ROM), a Flash memory or a magnetic drive memory.

[0099] The one or more processors 602 are configured to execute operating instructions 608 to cause the system / apparatus to perform any of the methods described herein. The operating instructions 608 may comprise code (i.e. drivers) relating to the hardware components of the system / apparatus 600, as well as code relating to the basic operation of the system / apparatus 600. Generally speaking, the one or more processors 602 execute one or more instructions of the operating instructions 608, which are stored permanently or semi-permanently in the non-volatile memory 606, using the volatile memory 604 to store temporarily data generated during execution of said operating instructions 608.

[0100] Any mentioned apparatus and / or other features of particular mentioned apparatus may be provided by apparatus arranged such that they become configured to carry out the desired operations only when enabled, e.g. switched on, or the like. In such cases, they may not necessarily have the appropriate software loaded into the active memory in the non-enabled (e.g. switched off state) and only load the appropriate software in the enabled (e.g. on state). The apparatus may comprise hardware circuitry and / or firmware. The apparatus may comprise software loaded onto memory. Such software / computer programs may be recorded on the same memory / processor / functional units and / or on one or more memories / processors / functional units.

[0101] Any mentioned apparatus / circuitry / elements / processor may have other functions in addition to the mentioned functions, and that these functions may be performed by the same apparatus / circuitry / elements / processor. One or more disclosed aspects may encompass the electronic distribution of associated computer programs and computer programs (which may be source / transport encoded) recorded on an appropriate carrier (e.g. memory, signal).

[0102] Any "computer" described herein can comprise a collection of one or more individual processors / processing elements that may or may not be located on the same circuit board, or the same region / position of a circuit board or even the same device. In some examples one or more of any mentioned processors may be distributed over a plurality of devices. The same or different processor / processing elements may perform one or more functions described herein.

[0103] The term "signalling" may refer to one or more signals transmitted as a series of transmitted and / or received electrical / optical signals. The series of signals may comprise one, two, three, four or even more individual signal components or distinct signals to make up said signalling. Some or all of these individual signals may be transmitted / received by wireless or wired communication simultaneously, in sequence, and / or such that they temporally overlap one another.

[0104] With reference to any discussion of any mentioned computer and / or processor and memory (e.g. including ROM, CD-ROM etc.), these may comprise a computer processor, Application Specific Integrated Circuit (ASIC), field-programmable gate array (FPGA), and / or other hardware components that have been programmed in such a way to carry out the inventive function.

[0105] The applicant hereby discloses in isolation each individual feature described herein and any combination of two or more such features, to the extent that such features or combinations are capable of being carried out based on the present specification as a whole, in the light of the common general knowledge of a person skilled in the art, irrespective of whether such features or combinations of features solve any problems disclosed herein, and without limitation to the scope of the claims. The applicant indicates that the disclosed aspects / examples may consist of any such individual feature or combination of features. In view of the foregoing description, it will be evident to a person skilled in the art that various modifications may be made within the scope of the disclosure.

[0106] While there have been shown and described and pointed out fundamental novel features as applied to examples thereof, it will be understood that various omissions and substitutions and changes in the form and details of the devices and methods described may be made by those skilled in the art without departing from the scope of the disclosure. For example, it is expressly intended that all combinations of those elements and / or method steps which perform substantially the same function in substantially the same way to achieve the same results are within the scope of the disclosure. Moreover, it should be recognized that structures and / or elements and / or method steps shown and / or described in connection with any disclosed form or examples may be incorporated in any other disclosed or described or suggested form or example as a general matter of design choice. Furthermore, in the claims means- plus-function clauses are intended to cover the structures described herein as performing the recited function and not only structural equivalents, but also equivalent structures.

Claims

Claims1. A computer implemented method for preventing roll over of a tipper vehicle, the method comprising: receiving, from each of a plurality of angle sensors of the tipper vehicle, respective angle measurements of the tipper vehicle while a dump box of the tipper vehicle is in use; receiving, from each of a plurality of load sensors of the tipper vehicle, respective load measurements of the dump box of the tipper vehicle while a dump box of the tipper vehicle is in use; determining, based on the respective angle measurements of the tipper vehicle and the respective load measurements of a dump box of the tipper vehicle, that the tipper vehicle is in an unsafe configuration; and in response to determining that the tipper vehicle is in an unsafe configuration, controlling the position of the dump box of the tipper vehicle.

2. The method of claim 1, wherein determining that the tipper vehicle is in an unsafe configuration comprises determining that the tipper vehicle is in an unstable configuration and / or that that the tipper vehicle will enter an unstable configuration.

3. The method of any of claims 1 or 2, wherein determining that the tipper vehicle is in an unsafe configuration comprises: determining a stability parameter value for each of the plurality of times based on the respective angle measurements of the tipper vehicle and the respective load measurements of the dump box; comparing the stability parameter value to one or more stability parameter thresholds; and determining that the tipper vehicle is in an unsafe configuration in response to the stability parameter value exceeding one or more of the threshold values.

4. The method of any preceding claim, wherein controlling the position of the dump box of the tipper vehicle comprises one or more of: preventing the dump box being raised further; restricting the rate at which the dump box can be raised; and / or lowering the dump box to a predefined position.

5. The method of any preceding claim, wherein determining that the tipper vehicle is in an unsafe configuration comprises:determining, based on the respective angle measurements of the tipper vehicle and the respective load measurements of a dump box, a current centre of gravity of the dump box; and comparing a lateral position of the centre of gravity of the dump box to one or more threshold positions.

6. The method of any preceding claim, wherein the plurality of angle sensors of the tipper vehicle are each located at one of a plurality of locations on the tipper vehicle.

7. The method of claim 6, wherein the plurality of locations comprise a dump box ram location and a dump box pivot location.

8. The method of any of claims 6 or 7, wherein determining that the tipper vehicle is in an unsafe configuration comprises: determining, based on the respective angle measurements at a plurality of locations on the tipper vehicle, a tipper vehicle roll angle and / or a dump box roll angle.

9. The method of any of claims 6 to 8, wherein determining that the tipper vehicle is in an unsafe configuration comprises: determining, based on the respective angle measurements at a plurality of locations on the tipper vehicle, a tipper vehicle twist angle.

10. The method of any preceding claim, wherein the plurality of load sensors of the tipper vehicle are each located at one of a plurality of load sensor locations, the plurality of load sensor locations comprising a dump box ram location and two sides of a dump box pivot location.

11. The method of any preceding claim, wherein the angle measurements of the tipper vehicle comprise an alignment angle between a cab of the tipper vehicle and a trailer of the tipper vehicle.

12. The method of any preceding claim, further comprising: receiving, from a plurality of wind pressure sensors located on either side of the dump box, respective wind pressure measurements; and determining, based on the respective wind pressure measurements, a net wind force on the dump box,wherein determining that the tipper vehicle is in an unsafe configuration is further based on the net wind force on the dump box.

13. The method of any preceding claim, further comprising: receiving, from a plurality of object detection sensors monitoring a space around the dump box, respective object detection data indicative of the presence or absence of an object in the space around the dump box, wherein determining that the tipper vehicle is in an unsafe configuration is further based on the respective object detection data.

14. The method of any preceding claim, further comprising: receiving, from a ram extension sensor, an extension value of a ram of the tipper vehicle; limiting a maximum ram extension speed based on a comparison of the extension value of the ram to the maximum extension value of the ram, wherein the maximum ram extension speed decreases as the extension value of the ram approaches the maximum extension.

15. A safety system for a tipper vehicle, the safety system comprising: a plurality of angle sensors; a plurality of load cells; one or more processors; and a memory, the memory storing computer readable instructions that, when executed by the one or more processors, causes the system to perform the method of any one or more of claims 1 to 11.

16. The safety system of claim 15, further comprising one or more wind pressure sensors, wherein the computer readable instructions, when executed by the one or more processors, cause the system to perform the method of claim 12.

17. The safety system of any of claims 15 or 16, further comprising one or more object detection sensors, wherein the computer readable instructions, when executed by the one or more processors, cause the system to perform the method of claim 13.

18. The safety system of any of claims 15 to 17, further comprising a ram extension sensor, wherein the computer readable instructions, when executed by the one or more processors, cause the system to perform the method of claim 14.

19. A tipper vehicle comprising the safety system of any of claims 15 to 18.

20. A computer program product comprising computer readable instructions that, when executed by a computer, cause the computer to perform the method of any of claims 1 to 14.

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