SPEED CONTROL OF A HANDLING MACHINE

Description

technical field

[0001] The invention relates to the field of handling machines, in particular the speed control of a handling arm of such handling machines. Technological background

[0002] In the field of material handling machinery, some countries have decided to adopt standards imposing specific requirements on manufacturers regarding the monitoring and control of machine stability in operation. The forces involved in the stability of a material handling machine in operation include both gravitational forces, also called static loads, namely the weights of the handling arm, the payload, the main body and / or other machine components; and inertial forces, also called dynamic loads, namely accelerations transmitted between the handling arm, the payload, the main body and / or other machine components due to movements performed in operation, in particular the movements of the handling arm and the payload relative to the main body.

[0003] Limiting inertial forces can be inherently achieved by restricting the speed of movement of the machine's components. Thus, the European standard EN 1459:1998, entitled "Safety of industrial trucks - Variable reach self-propelled trucks," mandates restricting the maximum descent speed of the handling arm. Specifically, this standard requires limiting this speed so that the sudden stopping of the handling arm, when loaded to its maximum payload, cannot cause the machine to tip over, while still allowing for a temporary lifting of the machine's rear wheels.

[0004] However, imposing a permanent speed limit would contradict the goal of work efficiency sought in the field of material handling equipment. Therefore, a permanent speed limit cannot constitute a satisfactory general solution to the problem of monitoring and controlling the stability of machines in operation.

[0005] Document EP 3 431 435 A1 discloses the preamble to claims 1 and 12. Summary

[0006] One key idea of ​​the invention is to provide methods for controlling the speed of the handling arm that are adapted to the different operating phases of the machine and to the stability conditions prevailing at each moment. To this end, another key idea of ​​this invention is to provide a handling machine in which the speed of the handling arm is capped at a maximum speed that takes into account the inertial and gravitational forces acting on the handling arm.

[0007] The invention proposes a handling machine comprising: a main body, a handling arm mounted on said main body and rotatable about a horizontal axis of rotation, an actuator configured to raise and lower said handling arm; an actuating element configured to send a request for the travel speed of the handling arm, a tipping detector configured to produce a signal relating to a tipping moment applied to the main body about a tipping axis of said handling machine, a speed detection device configured to determine a travel speed of the handling arm, and a control unit configured to receive the signals from the tipping detector, the actuating element, and the speed detection device and to: determine a maximum speed setpoint, and when the travel speed request is greater than said maximum speed setpoint,to control said actuator so that the movement speed of the handling arm does not exceed the maximum speed setpoint, in which the control unit is configured to determine the maximum speed setpoint based on the rate of change of the signal relating to the tipping moment and the movement speed of the handling arm.

[0008] In particular, the maximum speed setting takes into account the rate of change of the signal relating to the tipping moment with respect to the speed of movement of the handling arm.

[0009] Such a machine is advantageous because it allows the movement speed of the handling arm to be restricted to a maximum speed that depends on the rate of change of the signal related to the tipping moment. Thus, the determined maximum speed limits the inertial forces that can act on the handling machine. This restriction of movement speed to a maximum allows the handling arm to be positioned very close to the point where it could tip over, without destabilizing the machine.

[0010] According to another aspect of the invention, a method is proposed for controlling a handling machine comprising a main body and a handling arm mounted on said main body and rotatable about a horizontal axis of rotation, and an actuator for raising and lowering the handling arm, said method comprising steps for: acquire a request for the movement speed of the handling arm from an actuation element of the handling machine, determine a signal relating to a tipping moment applied to the main body around a tipping axis of said handling machine, determine a movement speed of the handling arm, determine a maximum speed setpoint, when the movement speed request is greater than said maximum speed setpoint, control said actuator so that the movement speed of the handling arm does not exceed the maximum speed setpoint, said method further comprising a step for determining the maximum speed setpoint as a function of a rate of change of the signal relating to the tipping moment and the movement speed of the handling arm.

[0011] The control process can be carried out by a control unit included in the handling machine.

[0012] According to advantageous embodiments, such a machine or process may have one or more of the following characteristics.

[0013] The actuator of the handling machine can be implemented in various ways. According to one embodiment, said actuator is a lifting actuator, for example of the hydraulic or electric type, connected on one side to the handling arm and on the other side to the main body and is configured to move the handling arm in rotation around the axis of rotation in order to perform upward and downward movements.

[0014] According to one embodiment, the actuator comprises a hydraulic actuator and a variable flow device for regulating a hydraulic flow to be supplied to the hydraulic actuator.

[0015] The speed detection device can be implemented in various ways. In one embodiment, the speed detection device includes an angle sensor configured to determine the inclination angle of the handling arm relative to a horizontal plane or to the main body of the handling machine. The angle sensor can be arranged at the axis of rotation. In another embodiment, the angle sensor can be an inclinometer. Alternatively, the angle sensor can be a sensor arranged on a moving part coupled to the handling arm. Such a sensor can be configured to determine the actuation stroke of the lifting actuator.

[0016] In one embodiment, the speed detection device includes signal processing means configured to determine the travel speed from successive measurements of the tilt angle of the handling arm. In another embodiment, the speed detection device includes a speed sensor that directly measures the speed of the handling arm, such as an angular or linear speed sensor. In one embodiment, the actuator includes a hydraulic actuator, and the machine further includes measuring means for measuring the hydraulic flow rate as travel speed information.

[0017] The actuating element can be configured to allow manual control of the handling arm by a handling machine operator. The actuating element can be implemented in various ways, for example, as a rocker lever, a control knob, a rotary button, a touchscreen, or other. In one embodiment, the actuating element is connected to the control unit via one or more sensors that provide a speed request signal to the control unit in the form of an electrical, hydraulic, or mechanical signal, representing the desired speed of the handling arm. These sensors may include, but are not limited to, switches, potentiometers, or Hall effect sensors.

[0018] The tilt detector can be implemented in various ways. In one embodiment, the handling arm has an end opposite the horizontal axis of rotation, and the main body is mounted on wheels supported by axles, and The tipping detector includes an extensometer arranged at an axle opposite the end of the handling arm, and the signal relating to the tipping moment is a signal relating to a deformation of the axle opposite the end of the handling arm.

[0019] According to one embodiment, the tipping detector includes a pressure sensor arranged at the actuator, the signal relating to a tipping moment being a signal relating to a load applied at the actuator.

[0020] 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.

[0021] The control unit can be configured to determine the maximum speed setpoint in many ways. In one embodiment, the control unit is configured to determine the maximum speed setpoint based on a dynamic component, which is determined according to the rate of change of the signal relating to the tipping moment and the speed of movement of the handling arm, and a static component.

[0022] In one embodiment, the control unit is configured to determine an initial travel time at which the travel speed is zero, and a maximum starting speed based on a time elapsed since the initial time. In this case, the control unit is configured to determine the maximum speed setpoint so that it does not exceed the maximum starting speed. In another embodiment, the maximum starting speed is calculated so that its variation does not exceed a predetermined maximum acceleration.

[0023] According to one embodiment, the control unit is configured to: The control unit determines the maximum speed setpoint at multiple successive times during the movement of the handling arm, and ignores any maximum speed setpoint determined at a later time that is lower than the maximum speed setpoint determined at an earlier time. This ensures that the actuator is controlled with successive maximum speed setpoints that increase throughout the movement. In this way, the maximum speed setpoints do not hinder the desired work efficiency of such machines. The control unit thus ensures the stability of the handling machine by restricting the movement speed without this restriction being too restrictive and therefore reducing the machine's performance.

[0024] The control unit can determine the dynamic and static components in different ways. In one embodiment, the control unit is configured to: select the static component based on a minimum static risk coefficient, and select the dynamic component based on the difference between the minimum static risk coefficient and a maximum static risk coefficient.

[0025] In particular, the minimum static risk coefficient and the maximum static risk coefficient are previously stored in a table or database.

[0026] According to one embodiment, the control unit is configured to determine a dynamic risk coefficient based on the rate of change of the signal relating to the tipping moment and the speed of movement of the handling arm.

[0027] In particular, the dynamic risk coefficient is predetermined and stored in a table or database based on the rate of change of the signal relating to the tipping moment and the speed of movement of the handling arm.

[0028] In one embodiment, the dynamic risk coefficient has a first value corresponding to a first value of the rate of change of the signal relating to the tipping moment and a first value of the speed of movement of the handling arm, and a second value corresponding to a second value of the rate of change of the signal relating to the tipping moment and the first value of the speed of movement of the handling arm. In this case, the first value of the rate of change of the signal relating to the tipping moment is less than the second value of the rate of change of the signal relating to the tipping moment, and the first value of the dynamic risk coefficient is less than the second value of the dynamic risk coefficient.

[0029] In other words, the dynamic risk coefficient shows an increasing evolution when, for the same value of the speed of movement, the rate of change of the signal relative to the tipping moment increases.

[0030] In one embodiment, the dynamic risk coefficient has a third value corresponding to the first value of the rate of change of the signal related to the tipping moment and a second value of the handling arm's travel speed. In this case, the first value of the handling arm's travel speed is less than the second value of the handling arm's travel speed, and the third value of the dynamic risk coefficient is less than the first value of the dynamic risk coefficient.

[0031] In other words, the dynamic risk coefficient shows an increasing evolution when, for the same value of the speed of variation of the signal relative to the tipping moment, the speed of movement decreases.

[0032] In one embodiment, the maximum speed setpoint is a function of a final risk coefficient determined by the static and dynamic components. In particular, the maximum speed setpoint decreases as the final risk coefficient increases. The control unit can be configured to determine the final risk coefficient so as to satisfy the following equation: R f = Rs min + Rs max − Rs min × Rd / 100 Rf being the final risk coefficient, Rs min being the minimum static risk coefficient, Rs max being the maximum static risk coefficient and Rd being the dynamic risk coefficient.

[0033] In this embodiment, the factor Rs minrepresents the static component and the factor ( Rs max - Rs min ) × Rd / 100 represents the dynamic component.

[0034] According to one embodiment, the speed of movement is a descent speed of the handling arm.

[0035] Such a handling machine can take the form of a telescopic handler, forklift, lifting crane, mechanical excavator, bucket loader, or other similar equipment. The handling arm can also be oriented around a vertical axis of the main body.

[0036] According to one embodiment, the process includes a step to determine the maximum speed setpoint as a function of a static component and a dynamic component determined as a function of the rate of change of the signal relating to the tipping moment and the speed of movement of the handling arm.

[0037] In one embodiment, the method involves determining an initial time of movement at which the speed is zero, and a maximum starting speed as a function of the time elapsed since the initial time. In this embodiment, the maximum speed setpoint is determined so that it does not exceed the maximum starting speed.

[0038] According to one embodiment, the process comprises: determine the maximum speed setpoint at a plurality of successive instants, during a movement of the handling arm, and ignore a maximum speed setpoint determined at a later instant that is lower than the maximum speed setpoint determined at an earlier instant so that the actuator is controlled with successive maximum speed setpoints that are increasing during the movement. Brief description of the figures

[0039] 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. [ fig.1 ] there figure 1 is a schematic representation of a material handling machine in the form of a forklift. fig.2 ] there figure 2 is a representation of a tilt detector that can be implemented by the handling machine of the figure 1 . [ fig.3 ] there figure 3 is a schematic representation of a speed control method that can be implemented in the handling machine of the figure 1 . [ fig.4 ] there figure 4is a schematic representation of a method for determining a maximum speed setpoint that can be implemented in the handling machine of the figure 1 . [ fig.5 ] there figure 5 is a schematic representation of a method for determining a maximum speed setpoint based on a static component and a dynamic component that can be implemented in the handling machine of the figure 1 . [ fig.6 ] there figure 6 is a schematic representation of a relationship between the dynamic component of the maximum speed setpoint and the rate of change of the signal relating to the tipping moment and the speed of the handling arm that can be used in the process of the figure 5 . [ fig.7 ] there figure 7 is a schematic representation of a relationship between a final risk coefficient and the maximum speed setpoint, which can be used in the process of the figure 5 . Description of the implementation methods

[0040] In the figure 1 A material handling machine 1, of the forklift type, is 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. The material handling machine 1 includes a material handling arm 6, for example of the telescopic type, mounted on the chassis 2 and rotatable about an axis of rotation 7, horizontal relative to the chassis 2. The material handling arm 6 includes a load carrier 14 articulated to the material handling arm 6 by the linkage 15 and configured to carry a payload 9.

[0041] The handling arm 6 is rotatable by means of a cylinder 8 connected to the chassis 2 and to the handling arm 6. The cylinder 8 allows the handling arm 6 to be moved up and down around the horizontal axis 7.

[0042] The position of the handling arm 6, and consequently its speed of movement, can be measured by a position sensor 18. For example, this position sensor 18 may include an inclinometer configured to measure the angle of inclination of the handling arm 6 relative to the frame 2. The speed of movement, in particular rotation, of the handling arm 6 can be determined from successive inclination measurements of the handling arm 6 by processing means included in the position sensor 18. Alternatively, the speed of movement, in particular rotation, of the handling arm 6 is measured directly by a speed sensor or by measuring the hydraulic flow rate supplied to the cylinder 8.

[0043] There figure 1The diagram shows the handling arm 6 carrying the payload 9 in a high position (solid line) and in several lower positions (dashed line). The static tipping moment exerted by the handling arm 6 in the forward direction increases as its position descends towards the horizontal.

[0044] To measure a signal representative of this tipping moment, a tipping detector can be provided in the handling machine 1. figure 1 schematically illustrates a tilt detector 11 arranged on the side of the rear axle 4.

[0045] There figure 2 illustrates an example of the implementation of the tilt detector 11. In the figure 2The rear axle 4 of the handling machine 1 comprises two wheel support arms 60 carrying rear wheels 62. Each wheel support arm 60 includes a strain gauge 61 configured to measure a tensile deformation of said wheel support arm 60 in a direction perpendicular to said arm 60. Alternatively, the strain gauges 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 strain gauges 61 can be used to form the indicator signal for the tipping moment, for example, as the average of the two measurement signals. Alternatively, it is possible to use a single strain gauge 61 to produce the indicator signal for the tipping moment.Preferably, the rear axle 4 is connected in an oscillating manner to the chassis 2 by means of a pivot 66 with longitudinal axis passing through a central part 65 of the axle.

[0046] In particular, the tipping detector 11 includes processing means for determining a rate of change of the signal relative to the tipping moment by time derivation of the signal relative to the tipping moment determined for example by the extensometer(s) 61.

[0047] In particular, the cylinder 8 actuates the movement of the handling arm 6 under the control of a control system. The control system comprises a control unit 10 and an actuating member 12 that can be operated by an operator, which are schematically sketched on the figure 1 In particular, the actuation member 12 is connected to the control unit by one or more sensors configured to provide a speed request signal to be executed by the handling arm 6.

[0048] The speed demand emitted by the actuation element 12 may be excessive, causing instability in the handling machine 1. For example, the speed demand may involve a quantity of motion that the machine is unable to absorb or dissipate without risk of tipping. To prevent this, the control unit 10 can implement the processes described in figures 3 to 5 to control the cylinder 8 according to the speed of movement request issued from the actuator 12 without exceeding a maximum speed setpoint.

[0049] There figure 3 is a schematic representation of a process 300 for controlling the speed of the handling arm 6 comprising the following steps: step 302: acquisition of the travel speed request from the actuator 12, step 304: determination of the maximum speed setpoint, step 306: comparison of the travel speed request and the maximum speed setpoint.

[0050] In response to the determination that the required travel speed is less than the maximum speed setpoint, the process 300 includes a step 308 of executing the movement at a speed equal to the required travel speed.

[0051] In response to the determination that the required travel speed exceeds the maximum speed setpoint, the process 300 includes a step 310 for controlling the cylinder 8 so that the travel speed of the handling arm 6 does not exceed the maximum speed setpoint. Specifically, in step 310, the handling arm 6 is controlled by the control unit 10 with a travel speed equal to the maximum speed setpoint.

[0052] Step 304 can be carried out according to process 400 of the figure 4 In particular, determining the maximum speed setting includes the following steps: Step 404: Determination of the movement speed of the handling arm 6, in particular the descent speed of the handling arm 6; Step 406: Determination of a rate of change of the signal relating to the tipping moment measured by the tipping detector 11; Step 408: Determination of the maximum speed setpoint as a function of a dynamic component dependent on the movement speed of the handling arm 6 and the rate of change of the signal relating to the tipping moment. The maximum speed setpoint may optionally be determined as a function of a static component as well.

[0053] The process 400 further includes, in response to the determination of a zero travel speed at an initial instant, a step 410 of determining a maximum starting speed as a function of a time elapsed since the initial instant and an evolution of the acceleration of the handling arm 6.

[0054] Process 400 also includes: Step 412 determines the minimum value between the maximum speed setpoint and the maximum starting speed, and step 414 assigns the minimum value to the maximum speed setpoint. In other words, when the maximum speed setpoint is greater than the maximum starting speed, the value of the maximum starting speed is assigned to the maximum speed setpoint. Thus, the control unit 10, implementing step 304, controls the handling arm 6 when an initial movement is initiated so that the speed of the handling arm does not exceed the maximum starting speed.

[0055] Step 408, determining the maximum speed setpoint based on the dynamic and static components, can be carried out according to method 500 of the figure 5In particular, process 500 can be repeated during a movement of the handling arm and the maximum speed setpoints determined at each iteration are advantageously stored in a memory 501.

[0056] Process 500 includes the following steps: step 504: determination of the speed of movement of the handling arm 6, in particular the descent speed of the handling arm 6, step 506: determination of a rate of change of the signal relating to the tipping moment measured by the tipping detector 11 or the extensometers 61, a step 510: determination of a dynamic risk coefficient as a function of the speed of movement of the handling arm 6 determined in step 504 and the rate of change of the signal relating to the tipping moment determined in step 506, a step 512: determination of a final risk coefficient as a function of a minimum static risk coefficient, a maximum static risk coefficient and the dynamic risk coefficient determined in step 510.

[0057] In particular, step 512 may consist of calculating the final risk coefficient using the following equation: R f = Rs min + Rs max − Rs min × Rd / 100 Rf being the final risk coefficient, Rs min being the minimum static risk coefficient, Rs max being the maximum static risk coefficient and Rd being the dynamic risk coefficient.

[0058] In particular, the factor Rs min represents the static component and the factor ( Rs max - Rs min ) × Rd / 100 represents the dynamic component.

[0059] Process 500 further includes the following steps: Step 514: Determining a candidate speed setpoint at the current time based on the final risk coefficient determined in step 512. Step 516: Determining the maximum value between the candidate speed setpoint at the current time in step 514 and a maximum speed setpoint determined at a time prior to the current time and stored in memory 501. Step 518: Assigning the candidate speed setpoint to the stored maximum speed setpoint if the previously stored maximum speed setpoint is lower than the candidate speed setpoint. Conversely, if the previously stored maximum speed setpoint is higher than the candidate speed setpoint, the maximum speed setpoint remains unchanged, the candidate speed setpoint is cleared, and the process returns to step 514 at the next iteration.

[0060] According to one embodiment, the dynamic risk coefficient is determined in step 510 by consulting a table represented on the Fig. 6where the x-axis 709 represents the rate of change of the signal related to the tipping moment and the y-axis 701 represents a dynamic risk coefficient Rd. The dynamic risk coefficient Rd varies, on the one hand, according to a factor represented by a curve 702 that depends on the rate of change of the signal related to the tipping moment and, on the other hand, on the descent speed of the handling arm. The curve 702 is increasing, so that the dynamic risk coefficient Rd shows an increasing trend as the rate of change of the signal related to the tipping moment increases for a given value of the descent speed of the handling arm 6.Furthermore, the dynamic risk coefficient exhibits a first value of 704 and a second value of 710 for the same value 706 of the rate of change of the signal related to the tipping moment, and a first value of 712 and a second value of 708, respectively, for the descent speed of the handling arm. The first value 704 of the dynamic risk coefficient is lower than the second value 710 of the dynamic risk coefficient, and conversely, the first value 712 of the descent speed is greater than the second value 708 of the descent speed. In other words, the dynamic risk coefficient increases when, for the same rate of change of the signal related to the tipping moment, the descent speed decreases.

[0061] The rate of change of the tipping moment signal represents the acquisition or loss of instability of the handling machine during the movement of the handling arm 6. When the rate of change of the tipping moment signal is low, the handling machine experiences a slower loss of stability. Conversely, when the rate of change of the tipping moment signal is high, the loss of stability of the handling machine is more rapid. The dynamic risk coefficient is higher when the movement speed that causes this loss of stability is low. A high rate of change of the tipping moment signal at a low movement speed implies a high sensitivity of the stability state to the tilt angle of the handling arm. Consequently, the dynamic risk coefficient is higher in this case.

[0062] According to one embodiment, the maximum speed setpoint is determined in step 514 by consulting a table represented on the Fig. 7 The maximum speed requirement represented by curve 802 shows a decreasing trend when the final risk coefficient 804 determined in step 512 increases.

[0063] Some of the elements shown, particularly the control unit, can be implemented in various forms, either individually or in a distributed manner, using hardware and / or software components. Usable hardware components include ASICs (Automatic System Integrated Circuits), FPGAs (Field Programmable Gate Arrays), and microprocessors. Software components can be written in various programming languages, such as C, C++, Java, or VHDL. This list is not exhaustive.

[0064] 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.

[0065] The processes and systems described above in the context of a telescopic handler are applicable to other material handling machines.

[0066] 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.

[0067] In claims, any reference sign in parentheses shall not be interpreted as a limitation of the claim.

Claims

1. A handling machine (1) comprising: a main body (2), a handling arm (6) that is mounted on said main body and is rotatable about a horizontal axis of rotation (7), an actuator (8) configured to raise and lower said handling arm, an actuating member (12) configured to output a request for a speed of movement of the handling arm, a tilt detector (11) configured to produce a signal relating to a tilting moment applied to the main body about a tilting axis of said handling machine, a speed detection device configured to determine a speed of movement of the handling arm (6), and a control unit (10) configured to receive the signals from the tilt detector (11), from the actuating member (12) and from the speed detection device, and: to determine a maximum speed setpoint, and characterized in that when the speed of movement request is higher than said maximum speed setpoint, to control said actuator (8) such that the speed of movement of the handling arm (6) is equal to the maximum speed setpoint, and in that the control unit (10) is configured to determine the maximum speed setpoint depending on a speed of variation in the signal relating to the tilting moment and the speed of movement of the handling arm (6).

2. The machine as claimed in claim 1, wherein the speed detection device comprises an angle sensor configured to determine an angle of inclination of the handling arm (6) with respect to the main body (2), and the control unit (10) is configured to determine the maximum speed setpoint depending on a static component and a dynamic component, said dynamic component being determined depending on the speed of variation in the signal relating to the tilting moment and the speed of movement of the handling arm (6).

3. The machine as claimed in claim 1 or 2, wherein the control unit (10) is configured: to select the static component depending on a minimum static risk coefficient, and to select the dynamic component depending on the difference between the minimum static risk coefficient and a maximum static risk coefficient.

4. The machine as claimed in any one of claims 2 to 3, wherein the control unit (10) is configured to determine a dynamic risk coefficient depending on the speed of variation in the signal relating to the tilting moment and on the speed of movement of the handling arm, said dynamic risk coefficient having a first value corresponding to a first value of the speed of variation in the signal relating to the tilting moment and to a first value of the speed of movement of the handling arm, and a second value corresponding to a second value of the speed of variation in the signal relating to the tilting moment and to the first value of the speed of movement of the handling arm, and wherein the first value of the speed of variation in the signal relating to the tilting moment is lower than the second value of the speed of variation in the signal relating to the tilting moment, and wherein the first value of the dynamic risk coefficient is lower than the second value of the dynamic risk coefficient.

5. The machine as claimed in claim 4, wherein the dynamic risk coefficient has a third value corresponding to the first value of the speed of variation in the signal relating to the tilting moment and to a second value of the speed of movement of the handling arm, and wherein the first value of the speed of movement of the handling arm is lower than the second value of the speed of movement of the handling arm, and wherein the third value of the dynamic risk coefficient is lower than the first value of the dynamic risk coefficient.

6. The machine as claimed in claim 3 in combination with either of claims 4 and 5, wherein the maximum speed setpoint depends on a final risk coefficient, and wherein the control unit is configured to determine the final risk coefficient so as to satisfy the following equation: R f = Rs min + Rs max − Rs min × Rd / 100 Rf being the final risk coefficient, Rsmin being the minimum static risk coefficient, Rsmax being the maximum static risk coefficient and Rd being the dynamic risk coefficient, and wherein the maximum speed setpoint decreases when the final risk coefficient increases.

7. The machine as claimed in any one of claims 1 to 6, wherein the control unit (10) is configured to determine an initial time of movement at which the speed of movement is zero, and a maximum starting speed depending on a time that has passed since the initial time, and wherein the control unit is configured to determine the maximum speed setpoint such that it does not exceed the maximum starting speed.

8. The machine as claimed in claim 7, wherein the maximum starting speed is calculated such that its variation does not exceed a predetermined maximum acceleration.

9. The machine as claimed in any one of claims 1 to 8, wherein the control unit (10) is configured: to determine the maximum speed setpoint at a plurality of successive times, during a movement of the handling arm, and to ignore a maximum speed setpoint determined at a later time which is lower than the maximum speed setpoint determined at an earlier time such that the actuator (8) is controlled with successive maximum speed setpoints which increase during the movement.

10. The machine as claimed in any one of claims 1 to 9, wherein the handling arm (6) has an end opposite to said horizontal axis of rotation and the main body (2) is mounted on wheels carried by axles, and the tilt detector comprises an extensometer (61) arranged on an axle opposite the end of the handling arm (6), and wherein the signal relating to the tilting moment is a signal relating to a deformation of the axle opposite the end of the handling arm (6).

11. The machine as claimed in any one of claims 1 to 10, wherein the speed of movement is a lowering speed of the handling arm (6).

12. A method (300) for controlling a handling machine (1) comprising a main body (2) and a handling arm (6) that is mounted on said main body (2) and is rotatable about a horizontal axis of rotation (7) and an actuator (8) for raising and lowering the handling arm, said method (300) comprising steps for: acquiring (302) a request for a speed of movement of the handling arm coming from an actuating member of the handling machine, determining a signal relating to a tilting moment applied to the main body about a tilting axis of said handling machine, determining (304, 400) a speed of movement of the handling arm, determining a maximum speed setpoint, characterized in that when the speed of movement request is higher than said maximum speed setpoint, controlling (310) said actuator (8) such that the speed of movement of the handling arm does not exceed the maximum speed setpoint, and in that said method also comprising a step for determining a maximum speed setpoint depending on a speed of variation in the signal relating to the tilting moment and the speed of movement of the handling arm.