Handling machine with arm and corresponding control method

Abstract

The invention relates to a handling machine (1) comprising a main body (2), a handling arm (6) mounted on said main body (2) and movable relative to the main body (2) in rotation between an upright position and a lowered position, an actuation device (8) configured to raise and lower said handling arm (6), a tilt detector (11) configured to produce a signal, called an instability signal relating to a tilting moment applied to the main body (2) around a tilting axis of said handling machine, and a control unit (10) configured to control the actuation device (8).The control unit (10) is configured to determine the rate of change of the instability signal value and to generate a stop or slowdown signal for the movement of the handling arm (6), depending on the rate of change of said instability value and a threshold value for the rate of change of instability. The invention also relates to a corresponding control method.

Description

FIELD OF INVENTION

[0001] The invention relates to the field of handling machines comprising a main body, generally intended to be placed on the ground, at least one handling arm intended to receive a payload to be moved, and an actuation device configured to execute a movement of the handling arm relative to the main body, and in particular to rolling handling machines.

[0002] Such a machine can notably be made in the form of a telescopic arm truck, lifting crane, mechanical excavator, bucket loader or other. EARLIER ART

[0003] We know of a handling machine, as described by JP3252006, comprising a machine body and a handling arm mounted movable relative to the machine body.

[0004] This machine is subjected, on the one hand, to gravitational forces due to the load carried by the handling arm and the machine's weight, and on the other hand, to inertial forces induced by the movements of the handling arm. These forces generate a tipping moment applied to the machine body, which can cause imbalance or even tipping when they exceed a certain threshold.

[0005] This machine includes a control means to limit the movements of the handling arm in order to prevent such a tipping of the machine.

[0006] In particular, the control means decelerates and then stops the handling arm when approaching a position of the handling arm where the tipping moment is greater than a given threshold.

[0007] This threshold varies depending on the angle of inclination of the handling arm relative to the ground and the approach rate at an authorized time.

[0008] However, using the angle of inclination of the arm and the value of the tipping moment as a control criterion for limiting or stopping the handling arm may prove unsuitable.

[0009] Indeed, a given arm angle and a given tipping moment can occur in different handling operations, some of which present a higher risk of tipping than others. A handling machine and a method for controlling a handling machine conforming to the preamble of claims 1 and 11 are described in document WO 2012 / 065157 A1.

[0010] The present invention aims to provide a new handling machine that can overcome all or part of the problems described above. SUMMARY OF THE INVENTION

[0011] To this end, the invention relates to a handling machine comprising: a main body, a handling arm mounted on said main body and movable relative to the rotating main body between an upright position and a lowered position, an actuation device configured to raise and lower said handling arm, a tilt detector configured to produce a signal, called an instability signal, relating to a tilting moment applied to the main body around a tilting axis of said handling machine, and a control unit configured to control the actuation device, characterized in that said control unit is configured to: determine the rate of change of the value of the instability signal, generate a stop or slowdown signal of a movement of the handling arm, as a function of the rate of change of said value of the instability signal and a threshold value of rate of change of the instability signal.

[0012] One idea behind this invention is to provide a handling machine in which the rate of change of the instability signal is taken into account to decide whether or not to stop or reduce the movement of the handling arm, in order to take into account the dynamic context of the handling operation.

[0013] In other words, unlike the prior art solution JP3252006 which acts on the handling arm according to static parameters such as the angle of the arm and the tipping moment at a given instant, the criterion used by the solution according to the invention is the rate of change of the instability signal, i.e. the rate of change of the tipping moment, and not the values ​​as such of the tipping moment and / or of the angle of the arm which do not reflect the dynamics of operation in progress.

[0014] Indeed, a value of the arm's tilt angle and a given value of the tipping moment at a given instant do not account for the operating dynamics of the handling machine, whereas this dynamic can play an important role in the risk of tipping of the handling machine.

[0015] Using the rate of change of the instability signal, i.e. the rate at which the stability of the handling machine degrades, as a criterion for stopping or restricting the movement of the arm makes it possible to limit the risk of tipping more effectively, while allowing a larger working space for the handling arm.

[0016] This rate of change of instability effectively takes into account all the factors influencing stability, such as the speed of machine operations, the geometric configuration of the structure, as well as the load handled.

[0017] In other words, the handling machine allows the operator to approach the machine's operating limits as closely as possible in terms of the handling arm's working space, and to do so safely. Furthermore, it also prevents the machine from tipping over due to excessive dynamics, even when the machine is in a configuration that might indicate an instability signal. The value of this signal might suggest a low risk of tipping, whereas a sudden stop by the operator could lead to a tipping.

[0018] The control unit is configured to calculate the threshold value for the rate of change of the instability signal based on the value of the instability signal. In a particular configuration, the control unit is also configured to calculate the threshold value for the rate of change of the instability signal based on a predefined value corresponding to a maximum rate of change of the instability signal.

[0019] Alternatively, the control unit can be configured to calculate the threshold value of the rate of change of the instability signal as a function of a geometry parameter of the handling machine, such as the angle that the handling arm forms with the ground support plane of the main body of the handling machine, and / or a configuration parameter of the handling machine, such as the configuration of the handling machine's stabilizers with or without ground support.

[0020] According to an advantageous feature of the invention, said control unit is configured to compare the value of the instability signal with a predefined instability threshold value, for example 85%, and, when the value of the instability signal is greater than or equal to said instability threshold value: compare said rate of change of the value of the instability signal with said threshold rate of change of the instability signal, and when said rate of change of said value of the instability signal is greater than or equal to said threshold rate of change of the instability signal, generate said stop or slowdown signal of the movement of the handling arm.

[0021] According to an advantageous feature of the invention, said threshold value of the rate of change of instability, denoted VJ threshold, is calculated according to the formula: VJ seuil = J stat_max − J * VJ max / J stat_max − J seuil J stat_max being a predefined value corresponding to a maximum value of the instability signal beyond which it is considered that, in static configuration of the handling machine, it tips over, J being the value of the instability signal, J threshold being a predefined threshold value of the instability signal, VJ max being a predefined value corresponding to a maximum rate of variation of the instability signal.

[0022] According to an advantageous feature of the invention, said handling arm is a telescopic arm that can be deployed and retracted along a longitudinal direction of said handling arm, and the actuation device is also configured to deploy and retract said handling arm.

[0023] According to an advantageous feature of the invention, said tilt detector comprises at least one extensometer, preferably provided on an axle, for example a rear axle, of the handling machine, and said tilt detector produces the instability signal as a function of the signal provided by the extensometer.

[0024] According to a particular embodiment, the handling arm is also orientable by rotation around an axis orthogonal to the ground support plane of the handling machine.

[0025] According to an advantageous feature of the invention, the handling machine includes a warning system comprising warning elements, such as indicator lights, the activation of which is a function of the rate of change of the instability signal.

[0026] According to an advantageous feature of the invention, said stop or slow down signal of a handling arm movement is a stop or slow down signal of a lowering or extending movement of the handling arm.

[0027] The invention also relates to a method for controlling a handling machine comprising a main body, a handling arm mounted on said main body and movable relative to the rotating main body between an upright position and a lowered position, and a tilt detector configured to produce a signal, called an instability signal, relating to a tilting moment applied to the main body around a tilting axis of said handling machine, characterized in that said method comprises the following steps: determine the rate of change of the value of the instability signal, generate a stop or slowdown signal of an arm movement as a function of the rate of change of said value of the instability signal and a threshold value of rate of change of the instability signal.

[0028] The threshold value of the rate of change of the instability signal is calculated based on the value of the instability signal.

[0029] Alternatively, the threshold value of the rate of change of the instability signal can be calculated as a function of a geometry parameter of the handling machine, such as the angle that the handling arm forms with the ground support plane of the main body of the handling machine, and / or a configuration parameter of the handling machine, such as the configuration of the stabilizers of the handling machine in contact with the ground or not.

[0030] According to an advantageous feature of the invention, the process comprises the following steps: compare said rate of change of the value of the instability signal with said threshold value of rate of change of the instability signal, and when said rate of change of said value of the instability signal is greater than or equal to said threshold value of rate of change of the instability signal, generate said stop or slow down signal of the movement of the handling arm, and otherwise allow the continuation of the movement of the handling arm. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The invention will be better understood, and other objects, details, features and advantages thereof will become more apparent from the following description of several particular embodiments of the invention, given solely by way of illustration and not limitation, with reference to the accompanying drawings. there figure 1 is a schematic representation of a handling machine; the figure 2 is a representation of a tilt detector that can be implemented by the handling machine of the figure 1 ; there figure 3 is a schematic representation of a control process that can be implemented by the handling machine of the figure 1 ; there figure 4 is a schematic representation of another control method that can be implemented by the handling machine of the figure 1 ; there figure 4A is a schematic representation of another control method that can be implemented by the handling machine of the figure 1 ; there figure 5 illustrates an example of a warning system that can be implemented by the material handling machine. figure 1 . DETAILED DESCRIPTION

[0032] The concept of the invention is described more fully below with reference to the accompanying drawings, in which embodiments of the concept of the invention are shown. In the drawings, the size and relative sizes of the elements may be exaggerated for clarity. Similar numbers refer to similar elements in all drawings. However, this concept of the invention can be implemented in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are proposed so as to make this description complete and to communicate the scope of the concept of the invention to those skilled in the art. The following embodiments are examined, for the sake of simplicity, in relation to the terminology and structure of a material handling machine with a material handling arm.

[0033] A reference throughout the specification to "an embodiment" means that a particular feature, structure, or characteristic described in relation to an embodiment is included in at least one embodiment of the present invention. Thus, the appearance of the phrase "in an embodiment" in various places throughout the specification does not necessarily refer to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

[0034] In the figure 1 A rolling material handling machine 1 with a handling arm has been shown. The material handling machine 1 comprises a chassis 2 supported on the ground by means of a front axle 3 and a rear axle 4.

[0035] The handling machine 1 includes a handling arm 6 mounted on the chassis 2 and rotatable around a horizontal axis of rotation 7 relative to the chassis 2. The handling arm 6 projects forward from the vehicle. In this configuration illustrated in the figure 1 The risk of tipping occurs in the forward direction around the tipping axis formed by the front wheels of the vehicle.

[0036] The handling arm 6 includes a load carrier 14 articulated to the handling arm 6 by the linkage 15 and configured to carry a payload 9.

[0037] In the example illustrated in the figures, the handling arm 6 is of the telescopic type. The handling arm 6 thus comprises at least two segments 61 and 62 that can be deployed by means of a deployment cylinder, not shown, arranged between the at least two segments 61 and 62. Alternatively, the arm may be a non-telescopic arm.

[0038] The machine includes an arm actuation device which includes in particular a lifting actuator, for example a hydraulic cylinder 8, which allows the handling arm 6 to be moved up and down around the horizontal axis 7, under the control of a control system.

[0039] The control system comprises a control unit 10, a hydraulic circuit (not shown) and a control element 12 actuated by an operator, which are schematically sketched on the figure 1 .

[0040] The control unit 10 includes an electronic and / or computer processing unit which includes data processing means such as a processor (microcontroller or microprocessor with memory) for processing data from machine sensors, such as the extensometer(s) 61 and the position detection system 18 shown below.

[0041] Thus, when it is specified that the unit or means of said unit are configured to perform a given operation, this means that the unit includes computer instructions and the corresponding means of execution which enable said operation to be performed and / or corresponding electronic components.

[0042] In other words, the described functions and steps can be implemented as a computer program or via hardware components (e.g., programmable gate arrays). Specifically, the functions and steps performed by the control unit can be carried out by instruction sets or computer modules implemented in a processor or controller, or by dedicated electronic components or FPGA or ASIC-type components. It is also possible to combine computer and electronic components.

[0043] The hydraulic circuit includes, for example, a hydraulic pressure source and a hydraulic distributor interposed between the hydraulic pressure source and a solenoid valve controlling the hydraulic cylinder 8. The solenoid valve controlling the hydraulic cylinder 8 is controlled by the control unit 10.

[0044] The control element 12 allows the handling arm 6 to be manually operated to raise and lower and to extend and retract said handling arm 6. The actuation element 12 may be in the form of a joystick movable in different directions to control the movements of the handling arm.

[0045] Normally, the control unit 10 allows the speed of the movement to be adjusted according to a movement request made by the operator by actuating the control element 12, and in particular according to a quantitative value produced by the user's action on the control element 12 and representing a speed level requested by the user. For example, the quantitative value could be the angle of inclination of a pivoting lever of the control element 12, where a higher angle represents a higher speed request and a zero angle of inclination (neutral position) represents a stop request.

[0046] As explained below, the control unit 10 can automatically decide to stop or limit the movement of the arm when given conditions are met, in connection with the rate of change of an instability signal (presented below), despite the operator's request on the control device 12.

[0047] The control unit 10 can be configured to stop or decrease the movement of the handling arm 6 by stopping or decreasing the hydraulic flow supplying the cylinder 8.

[0048] The automatic intervention of the control unit in the control of the arm reflects the fact that the operator has requested an arm movement resulting in a rate of change of instability that is too high compared to a threshold value of rate of change of instability, which can be predefined or defined in real time according to the embodiments and as explained below.

[0049] For example, starting from the top position illustrated on the figure 1If the operator requests a downward movement, the movement is executed as long as the rate of change of instability remains below a threshold value that can be predefined or defined in real time. The control unit 10 can be expected to instantly stop the arm's movement if the threshold rate of change of instability is reached or exceeded.

[0050] According to another embodiment, it can be provided that the control unit 10 controls a reduction in the speed of movement of the arm in the event of reaching or exceeding a threshold value of the speed of variation of the instability signal which in this case is preferably different from the threshold value causing the arm to stop.

[0051] It can also be provided according to another embodiment that the control unit determines the rate of change of instability which will result from the operator's request on the control element 12, and that it conditions the execution of the request on the fact that the rate of change of instability (estimated) is less than a threshold value.

[0052] The handling machine 1 also includes a position detection system 18 configured to produce a signal relating to a position of the handling arm 6, in particular an angle of inclination of the handling arm 6 relative to the chassis 2 and / or a deployment length of the handling arm 6.

[0053] The position detection system 18 includes, for example, a first sensor located at the axis 7 and arranged to measure the angle of inclination of the handling arm 6. The position detection system 18 includes, for example, a second sensor located at the deployment cylinder and arranged to measure a stroke of said deployment cylinder.

[0054] There figure 1 The diagram shows the handling arm 6 carrying the payload 9 in a raised, retracted position (solid line) and in several lower, extended positions (dashed line). In one particular aspect, the arm could be lowered without being extended. The static tipping moment exerted by the handling arm 6 in the forward direction increases as its position descends towards the horizontal. The static tipping moment also increases as the length of the handling arm 6 increases.

[0055] The handling machine 1 further includes a tipping detector 11 configured to produce a signal, called an instability signal, relating to a tipping moment applied to the chassis 2 around a tipping axis. This tipping axis may be located at the front axle 3. Stabilizing feet 5 may optionally be deployed to lift the front axle 3, in which case the stabilizer feet 5 define the tipping axis.

[0056] As an example, the instability signal can be expressed as a percentage value, with the convention that the higher the percentage value, the greater the corresponding tipping moment. This percentage is determined by calibrating the handling machine by assigning a 0% instability value to a configuration where the rear axle is heavily loaded and a 100% instability value to a configuration where the rear axle is completely unloaded.

[0057] In one embodiment, the tipping detector 11 is arranged at the cylinder 8. The tipping detector may include a pressure sensor arranged at the lifting actuator, the signal relating to a tipping moment being a signal relating to a load applied at the lifting actuator.

[0058] In one embodiment, the tipping detector comprises several sensors measuring various physical quantities, particularly those related to a load carried by the handling arm and / or the position of the handling arm. According to this embodiment, the tipping detector is configured to determine the signal related to a tipping moment based on these physical quantities.

[0059] In another embodiment, represented on the figure 2 , the tipping detector 11 is arranged at the rear axle 4.

[0060] In the figure 2 The rear axle 4 of the handling machine 1 includes two wheel support arms 60 carrying rear wheels 62. Each wheel support arm 60 includes an extensometer 61 configured to measure a tensile deformation of said wheel support arm 60 in a direction perpendicular to said arm 60.

[0061] Alternatively, the extensometers 61 are configured to measure a bending deformation of the wheel support arm 60, in particular a change in length between two spaced points on the wheel support arm 60. The measurement signals from the extensometers 61 can be used to form the indicator signal of the tipping moment, called the instability signal, for example, as the average of the two measurement signals. Alternatively, it is possible to use a single extensometer 61 to produce the instability signal. Preferably, the rear axle 4 is connected to the chassis 2 by means of a pivot 66 with a longitudinal axis passing through a central portion 65 of the axle.

[0062] In the particular case where the machine includes a turret allowing the arm to be oriented around a vertical axis (with reference to a horizontal ground support plane), the tilt detector 11 does not include an extensometer but includes a calculation module, for example integrated into the control unit, to calculate the value of the instability signal from cylinder pressure measurements and / or machine geometry measurements.

[0063] The control unit 10 is configured to receive signals from the tilt detector 11. The control unit 10 is configured to stop or limit the movement of the handling arm 6 based on the rate of change of the instability signal. It can be assumed that the control unit 10 includes a processing means configured to differentiate the value of the instability signal with respect to time and to apply digital or analog processing filters to the signal.

[0064] The control unit 10 determines the rate of change of the instability signal, which is then compared to a threshold value. As detailed below with examples of different control methods, the threshold value for the rate of change can be predefined or calculated in real time. When the rate of change of the instability signal is greater than or equal to this threshold value, the control unit stops or restricts the arm's movement speed. Otherwise, the arm's movement speed is not restricted.

[0065] In particular, lowering the arm significantly affects the risk of the machine tipping over, so it is useful to be able to interrupt or limit a lowering movement of the arm if the rate at which the stability of the machine degrades becomes too great.

[0066] The handling machine 1 advantageously includes a display 13 connected to the control unit 10. This display 13 can be configured to display a warning signal depending on the rate of change of the instability signal as explained below.

[0067] With reference to the figure 5 The handling machine includes a warning system that can be used in the handling machine 1 to assist the operator in piloting the handling arm 6 safely and efficiently and to provide feedback on the risk of tipping associated with the current operation.

[0068] The warning system includes, for example, a data processing module integrated into the control unit, and a display panel 13 or LED indicator lights. In one embodiment, the processing module generates display or illumination commands based on the instability signal and the rate of change of the instability signal to form a warning signal 500.

[0069] The warning signal 500 thus includes a part 51 relating to the static component of the risk of tipping, which is representative of the value of the instability signal and therefore of the tipping moment as such.

[0070] In particular, it can be foreseen that the first four lights 511, 512, 513, 514 from the bottom are assigned to this static component and that the number of lights activated is defined according to the value of the instability signal.

[0071] Warning signal 500 also includes a section relating to the dynamic component of the tipping risk, which represents the rate of change of the instability signal and therefore the rate of change of the tipping moment. Specifically, the four remaining top indicator lights 521, 522, 523, and 524 can be assigned to this dynamic component, and the number of lights activated can be determined based on the rate of change of the instability signal.

[0072] The illumination of the highest indicator 524 corresponds, for example, to the reaching or exceeding of the speed variation threshold of the instability signal, which informs the operator of the stoppage or reduction of the speed of the handling arm movement.

[0073] The operator can therefore use the warning signal 500 as a visual reference to adapt his movement request in order to remain close to the optimum level corresponding to the indicator 523 during the movement of the handling arm 6, in particular during a downward movement of the arm which has an important impact on the stability of the machine.

[0074] Alternatively, the warning signal can be audible. Examples of control processes

[0075] The control unit 10 can be configured to implement a control process 300 for the handling machine 1, as shown in the figure 3 .

[0076] As explained below, the control method 300 is used to stop or limit the movement of the handling arm 6 in order to prevent the handling machine 1 from tipping over, based on the rate of change of the instability signal. In one particular aspect, the control method is executed in real time.

[0077] In step 301, the tipping detector 11 provides the control unit 10 with an instability signal. As mentioned above, the tipping detector 11 may include a sensor, such as a strain gauge, which provides the control unit with this instability signal. Alternatively, the tipping detector may include one or more sensors associated with the handling machine, and a detection module, which may be part of the control unit, configured to determine or calculate the instability signal from a signal or signals provided by said sensor(s). The sensor(s) may include, for example, a pressure sensor in the cylinder 8 and a sensor measuring the extension of the handling arm.

[0078] As explained below, in step 305, the control process calculates the rate of change of the instability signal VJ. In other words, VJ corresponds to the rate at which the stability or instability of the handling machine changes as time progresses.

[0079] In step 303, the value of the instability signal is compared with a predefined instability threshold value, denoted J threshold. As an example, this instability threshold value can be set to 85%.

[0080] If the instability signal J remains below the predefined instability threshold J, then the control process does not intervene in the ongoing handling arm movement operation.

[0081] The control process loops through this step 303 until the instability signal reaches or exceeds the predefined instability threshold.

[0082] The control process then proceeds to step 309 in which a VJ threshold (speed of change threshold of the instability signal) is calculated.

[0083] The fact that the rate of change of the instability signal reaches or exceeds the threshold value may result from a too rapid lowering of the handling arm or, conversely, from a too rapid raising of the handling arm which could lead to a risk of tipping, whereas a movement of this type could in itself tend to improve stability.

[0084] To calculate this threshold rate of change of the instability signal, denoted VJ threshold, (step 309), the control unit 10 uses the current value of the instability signal J and takes into account (step 307) a predefined value, denoted VJmax, corresponding to a maximum rate of change of the instability signal. In other words, this maximum rate of change of the instability signal, VJmax, corresponds to a value beyond which the risk of the handling machine tipping over is considered too high. This predefined value, VJmax, can, for example, be set at 40% per second.

[0085] According to a particular aspect, the said threshold value of the rate of change of instability, denoted VJ threshold, is then calculated according to the formula: VJ seuil = J stat_max − J * VJ max / J stat_max − J seuil

[0086] With J stat_max: a predefined value corresponding to a maximum value of the instability signal beyond which, in a static configuration, the handling machine is considered to tip over. J stat_max can be set, for example, to 105%. In other words, J stat_max corresponds to a static stability limit for the handling machine. And as a reminder: J: the value of the instability signal, J threshold: the predefined threshold value of the instability signal, VJ max: the predefined value corresponding to a maximum rate of change of the instability signal.

[0087] Determining this threshold value of the instability variation rate VJ threshold allows control of the rate of variation of the instability signal VJ in order to reach a stability limit of the handling machine.

[0088] After determining this threshold value VJ, the control process 300 tests in step 311 the rate of change of stability, denoted VJ, in progress, with respect to this threshold value of rate of change VJ threshold.

[0089] As mentioned above, the rate of change of stability, denoted VJ, can be obtained in step 305 by the time derivative of the value of the instability signal J. In particular, it can be expected that the control unit 10 includes a processing module configured to process the digital signal corresponding to the instability signal, among other things, to differentiate it with respect to time.

[0090] When the rate of change of the instability value VJ is greater than or equal to the threshold rate of change of instability, then the control unit 10 generates a stop signal for the movement of the handling arm in step 313. Otherwise, the control unit 10 allows the handling arm 6 to continue moving in step 315.

[0091] Thus, when the rate at which the stability of the handling machine degrades is low, a maximum stability limit, such as that corresponding to the threshold (e.g., 105%), can be reached, allowing the handling machine to reach its maximum reach. Conversely, when the rate at which the stability of the handling machine degrades is high, the maximum stability limit cannot be reached, and the control unit 10 prematurely interrupts the movement of the telescopic arm, thus providing a greater safety margin compared to the maximum stability limit that can be reached when the rate at which stability degrades is low.

[0092] The operator may thus be led to operate the control of the handling arm in such a way that the rate of change of stability is low in order to achieve a maximum reach or working area with the handling arm.

[0093] In summary, in this ordering process 300 illustrated in the figure 3 Below a certain value of the instability signal, here 85%, no arm movement interruption occurs. Above 85%, a threshold value for the rate of change of the instability signal is calculated, beyond which the control unit 10 interrupts the arm movement. In particular, the closer the instability signal of the handling machine approaches the maximum static cutoff limit corresponding to Jstat_max (here 105%), the lower the permissible rate of change of the instability signal.

[0094] According to another embodiment, instead of a stop signal, the control unit generates a signal to slow down the arm.

[0095] In particular, it can be foreseen that the process includes a test of the variation of the speed of the instability signal VJ with respect to a first threshold value VJ threshold1 and a second threshold value VJ threshold2, so that if VJ threshold1 < VJ < VJ threshold2 then a slowing down of the handling arm is commanded, while if VJ >= VJ threshold2 then the stopping of the arm is commanded.

[0096] Another embodiment of the control method 400 for the handling machine 1 is shown in the figure 4 .

[0097] In this embodiment, the control unit 10 calculates the rate of change of the instability signal VJ in step 405 and compares it in step 411 with a predefined threshold value, denoted VJ_predefined_threshold, which can be read in step 409. If the rate of change of the instability signal VJ reaches or exceeds this predefined threshold value VJ_predefined_threshold, then the control unit 10 stops or restricts the movement speed of the handling arm in step 413. Otherwise, in step 415, the control unit 10 does not stop or restrict the movement speed of the handling arm and thus allows the handling arm to continue moving.

[0098] In other words, when the rate of change of the tipping moment exceeds a predetermined threshold, the movement of the arm is stopped or the maneuvering speed of the arm is reduced.

[0099] It should be noted that in this embodiment, the control method allows the arm's movement speed to be stopped or reduced independently of an instability signal threshold, i.e., independently of whether the machine's instability signal is approaching a tipping moment threshold or not.

[0100] According to another embodiment illustrated in the figure 4A The rate of change of the instability signal, beyond which operations are stopped or restricted, may depend on the machine's geometric parameters and / or machine configuration parameters, in order to adapt the machine's behavior to its work area. Machine geometry parameters may include the lifting angle of the handling arm and / or the extension length of the handling arm. Machine configuration parameters may include whether or not the stabilizers 5 are detected when in contact with the ground.

[0101] Thus, according to the embodiment illustrated in the figure 4A and which incorporates steps from process 400 of the figure 4 A control method 400A is also proposed in which the threshold value, denoted VJ threshold_angle in this embodiment, to which the rate of change of the instability signal VJ is compared (step 411), is defined in step 409A as a function of the angle of the handling arm, the value of which is acquired in step 407A. This angle corresponds to the angle that the arm makes with respect to the horizontal when the handling machine is on a horizontal surface. As mentioned above, other geometry and / or configuration parameters of the handling machine can be used.

[0102] Although the invention has been described in connection with several particular embodiments, it is clearly evident that it is by no means limited to them and that it includes all technical equivalents of the means described as well as their combinations if these fall within the scope of the invention.

[0103] The use of the verb "comporter", "comprendre" or "include" and its conjugated forms does not exclude the presence of other elements or steps than those stated in a claim.

[0104] In claims, any reference sign in parentheses shall not be interpreted as a limitation of the claim.

Claims

1. A handling machine (1) including: - a main body (2), - a handling arm (6) mounted on said main body (2) and rotatable relative to the main body (2) between a raised position and a lowered position, - an actuating device (8) configured to raise and to lower said handling arm (6), - a tipping detector (11) configured to produce a signal called the instability signal relating to a tipping moment applied to the main body (2) about a tipping axis of said handling machine, and - a control unit (10) configured to control the actuating device (8), said control unit (10) is configured: - to determine the rate of variation of the value of the instability signal, - to generate a signal to halt or to slow movement of the handling arm (6) as a function of the rate of variation of said value of the instability signal and a threshold value for the rate of variation of the instability signal characterized in that the control unit (10) is configured to calculate the threshold value of the rate of variation of the instability signal as a function of the value of the instability signal.

2. The handling machine (1) as claimed in claim 2 characterized in that the control unit (10) is configured to calculate the threshold value of the rate of variation of the instability signal also as a function of a predefined value corresponding to a maximal rate of variation of the instability signal.

3. The handling machine (1) as claimed in claim 1 characterized in that the control unit (10) is configured to calculate the threshold value of the rate of variation of the instability signal as a function of a geometrical parameter of the handling machine such as the angle between the handling arm (6) and the plane in which the main body (2) of the handling machine (1) bears on the ground and / or a configuration parameter of the handling machine such as the configuration with the stabilizers (5) of the handling machine bearing on the ground or not.

4. The handling machine (1) as claimed in any one of claims 1 to 23 characterized in that said control unit (10) is configured to compare the value of the instability signal with a predefined instability threshold value, for example 85%, and if the value of the instability signal is above or equal to said instability threshold value: - to compare said rate of variation of the value of the instability signal with the threshold value of the rate of variation of said instability signal, and - if said rate of variation of said value of the instability signal is above or equal to the threshold value of the rate of variation of said instability signal to generate said signal to halt or to slow the movement of the handling arm (6).

5. The handling machine (1) as claimed in any one of claims 1, 2, 4 characterized in that the threshold value of the rate of variation of said instability signal denoted VJthreshold is calculated using the formula: VJ threshold = J stat_max − J * VJ max / J stat_max − J threshold Jstat_max being a predefined value corresponding to a maximal value of the instability signal beyond which it is considered that in a static configuration of the handling machine the latter tips, J being the value of the instability signal, Jthreshold being a predefined threshold value of the instability signal, VJmax being a predefined value corresponding to a maximal rate of variation of the instability signal.

6. The handling machine (1) as claimed in any one of the preceding claims characterized in that said handling arm (6) is a telescopic arm deployable and retractable in a longitudinal direction of said handling arm and the actuating device (8) is also configured to deploy and to retract said handling arm (6).

7. The handling machine (1) as claimed in any one of the preceding claims characterized in that said tipping detector (11) includes at least one extensometer (61) preferably arranged on an axle (60), for example a rear axle, of the handline machine, and said tipping detector (11) produces the instability signal as a function of the signal supplied by the extensometer (61).

8. The handling machine (1) as claimed in any one of claims 1 to 6 characterized in that the handling arm (6) can also be oriented by rotating it about an axis orthogonal to the plane in which the handling machine (1) bears on the ground.

9. The handling machine (1) as claimed in any one of the preceding claims characterized in that the handling machine (1) includes a warning system including warning elements such as indicator lamps switching on of which is a function of the rate of variation of the instability signal.

10. The handling machine (1) as claimed in any one of the preceding claims characterized in that said signal to halt or to slow movement of the handling arm (6) is a signal to halt or to slow a movement of lowering or extending the handling arm (6).

11. A method of controlling a handling machine (1) including a main body (2), a handling arm (6) mounted on said main body (2) and rotatable relative to the main body (2) between a raised position and a lowered position, and a tipping detector (11) configured to produce a signal called the instability signal relating to a tipping moment applied to the main body (2) about a tipping axis of said handling machine, characterized in that said method includes the following steps: - determining (305; 405) the rate of variation of the value of the instability signal, - generating (313; 413) a signal to halt or to slow movement of the arm as a function of the rate of variation of said value of the instability signal (305; 405) and a threshold value for the rate of variation of the instability signal (309; 409; 409A) - calculate the rate of variation of the instability threshold value as a function of the value of the instability signal.

12. The method as claimed in claim 11 characterized in that the threshold value of the rate of variation of the instability signal is calculated (409A) as a function of a geometrical parameter of the handling machine such as the angle between the handling arm (6) and the plane in which the main body (2) of the handline machine (1) bears on the ground and / or a configuration parameter of the handling machine such as the configuration with the stabilizers (5) of the handling machine bearing on the ground or not.

13. The method as claimed in one of claims 11 to 12 characterized in that the method includes the following steps: - comparing (311; 411) said rate of variation of the value of the instability signal with the threshold value of the rate of variation of said instability signal, and - if said rate of variation of said value of the instability signal is above or equal to the threshold value of the rate of variation of said instability signal, generating (313; 413) said signal to halt or to slow the movement of the handling arm and otherwise to authorize (315; 415) continued movement of the handling arm (6).

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