Handling machine comprising a chassis tilt sensor system and corresponding control method

Abstract

The invention relates to a load or person handling machine, the maximum permissible speed of which is limited according to the machine's angle of inclination (A), such that, over at least a portion of an angular range [0; Awmax], the maximum permissible set speed decreases until it reaches zero when the measured angle of inclination of the chassis reaches the maximum angle value Awmax of said angular range. Figure for the abstract: Fig. 3

Description

Title of the invention: Handling machine comprising a chassis tilt sensor system and corresponding control method FIELD OF INVENTION

[0001] The present invention relates generally to handling machines, comprising a chassis tilt sensor system. EARLIER ART

[0002] As an example among handling machines, prior art is known of platform lifting machines (lifting machine) intended for the lifting of persons which serve to facilitate access to a work area at height.

[0003] Such a machine typically comprises a rolling chassis equipped with a powertrain. The chassis may accommodate a turret which, via a movement mechanism, carries a lifting structure, such as a lifting arm system, to the end of which is coupled a work platform on which an operator is located. The work platform is in the form of a work floor equipped with guardrails to protect against the risk of falls.

[0004] The work platform is usually equipped with a machine control interface, such as a control panel, which allows the operator to control the lifting and lowering movement of the lifting structure and the movement of the machine on the ground.

[0005] It is desirable to be able to stop the machine's movement on the ground when the chassis's tilt limit is reached in order to avoid exceeding the tilt limit and risking the machine tipping over. However, it has been observed that there is a risk of tipping even when the machine is stopped.

[0006] It is understood that a stability problem can also arise for other types of handling machines, such as telescopic handlers, in particular when the handling system carried by the chassis of the machine, which includes for example a telescopic arm, is in a deployed, raised or extended configuration which increases the instability of the machine compared to the folded, lowered or retracted configuration of the handling system.

[0007] The present invention aims to provide a new machine and a corresponding new process to overcome all or part of the problems described above. Summary of the invention

[0008] To this end, the invention relates to a machine for handling loads or person, including: - a rolling chassis; - a motorized drive system for moving the chassis on the ground; - a chassis tilt sensor system allowing measurement of the chassis tilt angle; - a handling system that is capable of taking on different configurations in space relative to the chassis; - a processing unit enabling the motorized drive system to be controlled when the chassis is moving on the ground; - a speed control system, such as a joystick, allowing the transmission to the processing unit of an instruction for the machine's ground movement speed; - a control system, such as a joystick, for the handling system to control its configuration in space; the processing unit being configured to operate the machine in two distinct modes, including: - a mode called working mode for which the handling system is in a first spatial configuration called working mode, for example deployed at height, and - a mode called transport mode for which the handling system is in a second spatial configuration, for example folded or retracted, for which the machine has greater stability than in the said working configuration of the handling system of the machine; The processing unit is configured to, in working mode, define a maximum allowable value of controlled speed for the ground movement of the machine which is a function of the measured angle of inclination of the chassis, and which decreases as the angle of inclination increases from a given value of inclination, which may be zero, towards a maximum angle value.

[0009] Such a design of the handling machine allows the handling machine to stop moving on the ground without exceeding a maximum inclination threshold. This threshold can be a maximum side slope threshold (i.e., a lateral inclination threshold) or a longitudinal inclination threshold. It can also be provided that the inclination threshold comprises a combination of longitudinal and lateral inclination thresholds. The machine's ground movement includes forward and backward movement.

[0010] The gradual decrease in the maximum permissible ground speed of the handling machine as the chassis tilt angle increases allows the machine's ground movement to be slowed down before reaching the maximum permissible chassis tilt angle. Slowing the machine down allows for effective anticipation of stopping to avoid a sudden movement that could destabilize it.

[0011] Conversely, in prior art solutions, the stopping occurs abruptly when the threshold tilt angle is reached, without any anticipation, which risks causing the machine to tip over. Furthermore, it has been observed that with prior art machines, when the maximum permissible chassis tilt angle is reached and a ground travel stop command is triggered, the maximum permissible chassis tilt angle is often ultimately exceeded due to the machine's inertia. This can lead to instability and stalling of the turret's rotation, if present.

[0012] It should be noted that the processing unit modifies the maximum permissible value of the machine's commanded ground speed according to the measured chassis tilt angle, but that the processing unit allows the operator, or a control program in the case of an autonomously driven machine, to control the machine's ground speed, which nevertheless remains limited by said maximum permissible value of the commanded ground speed, itself defined according to the measured chassis tilt angle. In other words, the processing unit adjusts the maximum value of the commanded speed according to the measured chassis angle: the machine's commanded ground speed can then vary between a value of zero and said maximum value, which has been defined according to the measured chassis angle.

[0013] According to a preferred embodiment, the processing unit is configured to modify the maximum allowable value of the controlled speed in the direction of a reduction when the chassis tilt value exceeds a given tilt value.

[0014] In other words, the maximum permissible value of the controlled speed is reduced when the chassis tilt exceeds a first tilt value so that it approaches the maximum permissible tilt value, i.e., if, in absolute value, the difference between the measured chassis tilt angle and the maximum permissible tilt value is less than a given threshold value (in other words, if the distance or difference between the measured chassis tilt angle and the maximum permissible tilt value is less than a given threshold value). As long as the difference is sufficient, i.e., greater than or equal to the given threshold value, the processing unit can be configured to maintain the maximum permissible value of the controlled speed at a constant value (i.e., a plateau).

[0015] According to one embodiment, for a chassis tilt angle that progresses from a given initial tilt value to the maximum permissible tilt value, the maximum permissible value of the controlled speed evolves along a decreasing slope, for example, a decreasing slope of constant value, preferably without depending on external conditions (other than conditions impacting the angle of the chassis). As an example, the maximum authorized speed does not depend on the state of friction of the ground, but of course depends on the inclination of the ground since this has repercussions on the inclination of the chassis relative to the horizontal plane.

[0016] The reduction of the maximum permissible value of the controlled speed can be adjusted according to the inertia of the machine and / or according to a latency time of the stop control system when the machine is moving on the ground.

[0017] The machine may also include one or more of the following features taken in any technically permissible combination.

[0018] According to one embodiment of the invention, the processing unit is configured to, in transport mode, define a maximum authorized value of controlled speed for the ground movement of the machine which is non-zero in a given angular range which includes said maximum angle value defined for the working mode.

[0019] According to an embodiment of the invention, in which the processing unit is configured to, in transport mode, define a maximum authorized value of controlled speed for the ground movement of the machine which is a function of the measured angle of inclination of the chassis, and which decreases as the angle of inclination increases from a given value of inclination, which may be zero, towards a maximum angle value.

[0020] According to an embodiment of the invention, wherein said maximum angle value in transport mode is greater than the maximum angle value in working mode.

[0021] According to one embodiment of the invention, in working mode, when the chassis tilt angle reaches the maximum value, so that the machine comes to a stop, the processing unit is configured to allow the machine to switch from working mode to transport mode by control of the handling system, the processing unit being configured so that, when the machine is in transport mode, it allows the vehicle to move on the ground up to a maximum chassis tilt angle that is greater than the maximum chassis tilt angle defined in working mode, so as to allow the machine to return to an area of ​​the ground for which the chassis angle is less than the maximum chassis tilt value defined in working mode.

[0022] According to an embodiment of the invention, in which the speed control system includes a manual speed control element operable over a given range, such as a joystick, the processing unit is configured to, in response to the operator's actuation of said manual control element, control the motorized drive system to move the chassis on the ground, to move the machine according to a commanded speed value that is less than or equal to said maximum authorized value in working mode and that is defined according to of the position of the manual control device.

[0023] According to one embodiment of the invention, following the movement of the manual control member to control the speed, the processing unit defines the value of the controlled speed by multiplying the maximum allowed value of the controlled speed by the ratio between the stroke traveled by the manual control member and the total available stroke of said manual control member.

[0024] According to one embodiment of the invention, the processing unit is configured to, over the angular range [0; Awl] of chassis inclination, the value Awl being less than the maximum angle value Awmax, define the maximum authorized value of controlled speed for the ground movement of the machine in working mode, as being equal to a constant value.

[0025] According to one embodiment of the invention, the handling system carried by the chassis comprises a set of arms articulated between each other and a platform coupled to said set of arms, said set of arms being able to take a configuration deployed in height, according to which the working mode is activated, and a folded configuration according to which the transport mode is activated.

[0026] According to one embodiment of the invention, the machine comprises a turret mounted to rotate on the chassis around an axis orthogonal to the ground support plane of the machine's wheels, the handling system being carried by the turret.

[0027] The invention also relates to a method for controlling a machine according to any one of the preceding embodiments, said method comprising the following steps: - control of the handling system, in the sense of a deployment or an extension of an element of the handling system, so that the processing unit determines that the machine is in working mode; - decrease in the maximum permitted value for the commanded speed of movement of the machine when the measured angle of inclination of the chassis increases; - control of the machine's travel speed to a value less than or equal to the maximum allowed value; - reaching the maximum tilt angle of the chassis defined for the working mode so that the maximum allowed value for the commanded travel speed is zero; - control of the handling system, in the direction of a folding or retraction of an element of the handling system, so that the processing unit determines that the machine is in transport mode; - movement of the machine in said transport mode to reach an area for which the measured angle of inclination of the chassis falls below the maximum inclination value defined for the working mode; - preferably, control of the handling system to return to working mode.

[0028] The maximum permitted speed reduction can thus be carried out progressively, until movement comes to a stop on the ground when the tilt sensor measures an angle equal to the maximum permitted tilt threshold. Brief description of the drawings

[0029] Other features and advantages of the invention will become apparent from the following description, which is purely illustrative and not limiting and should be read in conjunction with the accompanying drawings, on which:

[0030] - [Fig. 1] [Fig. 1] is a schematic view of a handling machine according to a embodiment of the invention, the chassis of the machine having a first value of inclination (which can correspond to the angle of inclination of the ground with respect to the horizontal when the ground is flat and the machine is supported by its wheels on this ground), so that the chassis has a first value of inclination and the maximum authorized value of the controlled ground travel speed is limited to a first given value;

[0031] - [Fig.2] [Fig.2] is a schematic view of the machine [Fig.1], the chassis of the machine having a second inclination value which is greater than the first inclination value of [Fig.1], so that the maximum permissible value of the commanded ground travel speed is limited to a second given value which is less than the first value;

[0032] - [Fig.3] [Fig.3] is a graph showing, for each of two modes of operation operation of the machine, namely a working mode and a transport mode, a control law of the maximum allowable value of the controlled ground speed of the machine, as a function of the angle of inclination of the chassis of the machine, for a machine according to an embodiment of the invention, such as the machine of [Fig.1], the maximum allowable value of the controlled speed being, in absolute value, preferably constant up to a certain angle of inclination of the chassis, then being decreasing until reaching a value of zero for the maximum allowable angle of inclination of the chassis;

[0033] - [Fig.4] [Fig.4] is a flowchart showing the steps of a control process of a handling machine according to an embodiment. DETAILED DESCRIPTION

[0034] Embodiments of the invention are described below with reference to the accompanying drawings. 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, the invention can be implemented in many different forms and should not be construed as being limited to the implementation methods described here.

[0035] A reference throughout the description 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.

[0036] A load or person handling machine 1 is proposed, comprising a handling system 4 carried by a chassis 2 directly or indirectly, the risk of instability of which is reduced when the ground movement of the handling machine is stopped, by means of a decrease in the maximum authorized value of the controlled ground movement speed as the inclination of the chassis approaches a maximum authorized inclination value (threshold value).

[0037] Handling machine

[0038] With reference to the figures, a handling machine 1 of the platform type has been represented, allowing work in elevation of persons.

[0039] Alternatively, the handling machine may be another type of handling machine, such as a telescopic arm truck whose arm can be equipped with a working tool, such as a bucket or forks, or with a platform for an operator to work at height.

[0040] Thus the continuation of the description made in the case of a platform applies to other types of handling machine comprising a load or person handling system which is capable of selectively presenting a deployed, or raised or extended configuration, depending on the type of handling system, and a folded, or lowered or retracted configuration (depending on the type of handling system), which provides the machine with better stability than the deployed, or raised or extended configuration.

[0041] The platform 1 comprises a rolling chassis 2 equipped with a ground-moving drive system 12 for chassis 2. The drive system can be of the thermal or electric type.

[0042] At least some of the wheels are steering wheels, having a variable orientation relative to the chassis 2, to allow steering of the nacelle 1. The chassis is equipped with a steering control system for the steering wheels.

[0043] According to one embodiment of the invention and as illustrated in Figures 1 and 2, the chassis 2 carries a turret 3 mounted to pivot about an axis orthogonal to the ground support plane of the machine's wheels. Thus, the pivot axis of the turret is vertical when the machine is supported by its wheels on a horizontal flat surface.

[0044] The turret 3 carries a handling system 4 which includes an elevating structure 5 which is equipped with a working platform 7 on which an operator can be present.

[0045] The platform 7 is equipped with a control panel 11. The control panel 11 comprises a first control element 1 IA, such as a joystick, which controls the machine's ground movement, and a second control element, such as a joystick, which controls the handling system and, in particular, the deployment and retraction of the lifting structure. The first and second control elements may be implemented by a single element that can be actuated differently depending on the desired function, or by two separate elements.

[0046] The control panel 11 thus allows the operator to transmit to the processing unit 10 instructions for controlling the ground movement of the chassis and / or instructions for lifting or lowering the handling system or parts of said system, such as the platform 7.

[0047] Elevation structure

[0048] The lifting structure 5 extends between the turret 3, when present, and the platform 7. The lifting structure 5 may comprise a set of arms 6 articulated to each other and to the chassis, via the turret if applicable. As in the example illustrated in the figures, the platform 7 may be mounted on a pendulum system 69 articulated to the end of a lifting arm 68 (which may be telescopic) of the lifting structure 5. The lifting arm 68 may itself be articulated to another part 67 of the lifting structure comprising one or more other arms, such as a set of arms arranged in a parallelogram, which may be articulated with respect to the chassis (via the turret 3 if applicable). Elements 67, 68, and 69 may be considered as forming part of the set of arms 6.

[0049] The lifting (deployment) and lowering (folding) movement of the lifting structure 5 is made possible by a system of jacks arranged with the lifting structure 5 to fold or deploy the lifting structure 5.

[0050] The cylinder system can be hydraulic or electric. In the case of a hydraulic cylinder system, a hydraulic circuit system (not shown) supplies the hydraulic cylinder system. The hydraulic circuit system usually includes a cylinder supply circuit and an oil pressure system, such as a pump, actuated by a motor. This motor may be wholly or partially shared with a motor of the ground-based drive system or be a separate motor. The processing unit controls the hydraulic circuit system to control the supply of power to the cylinder system.

[0051] Chassis tilt

[0052] The machine includes a tilt sensor system 19 for measuring, preferably in real time, an angle A of inclination of the chassis 2 with respect to the horizontal (preferably a longitudinal and / or lateral inclination of the chassis with respect to the horizontal plane). "In real time" means that the inclination measurement is performed during the operation of the machine, at a given frequency, for example 100 Hz.

[0053] Generally, and as illustrated in Figures 1 and 2, preferably from a given angle of inclination, for example Atl or AW1, for an angle of inclination of the chassis which has a first value Al ([Fig.1]) then a second value A2 ([Fig.2]) greater than Al, the maximum allowable value of the controlled speed V2 defined for the angle A2 is less than the maximum allowable value of the controlled speed VI defined for the angle Al.

[0054] As mentioned above, the machine includes a processing unit 10 for controlling the drive system 12, which moves the chassis on the ground to move the machine at a set speed. A set speed signal can be provided to the processing unit by actuation of the control element 1IA of the control panel 11, such as a joystick, connected to the processing unit 10. Preferably, the signal represents the actuation stroke of the element. Thus, a displacement of X% of the element over its available stroke can be interpreted by the processing unit 10 as a speed command at X% of the maximum permissible speed.

[0055] As detailed below, the processing unit 10 adapts the value of the maximum permitted speed according to the measured value of the angle A of inclination of the chassis 2 for at least a part of the permitted angular inclination range.

[0056] The angle of inclination of the chassis may include the angle, called the lateral angle of inclination, which forms a normal to the ground support plane of the wheels of the machine with the vertical in a plane which passes through said vertical and a lateral horizontal axis of the machine (i.e. a lateral horizontal axis orthogonal to the longitudinal axis of the machine).

[0057] In addition or as an alternative, the chassis inclination angle may include the angle, called the longitudinal inclination angle, formed by a normal to the ground contact plane of the machine's wheels with the vertical in a plane passing through the vertical and a longitudinal axis of the machine (i.e., a front-to-rear axis of movement of the machine). For a vehicle comprising two front wheels and two rear wheels, the longitudinal axis of the machine is the axis parallel to the ground contact plane of the machine's wheels and passing between the two rear wheels and between the two front wheels of the vehicle.

[0058] It can thus be foreseen that the angle of inclination is the lateral angle of inclination or the longitudinal angle of inclination or the resultant of the combination of the two angles.

[0059] Operating modes

[0060] The lifting structure 5 is capable of taking a deployed height configuration adapted to the work at height of the operator present on the platform 7, called working mode, and a folded configuration, relative to said deployed configuration, adapted to the transport of the machine, called transport mode, more stable than in working mode.

[0061] The processing unit can be configured to determine whether the machine is in working mode or transport mode based on data from a position sensor system, for example an angular position or arm extension sensor, of all or part of the handling system, and / or a turret orientation sensor.

[0062] It is understood that the transport mode can be defined for a partially deployed configuration of the handling system, and that the working mode can be defined for a partially folded configuration of the handling system. In transport mode, the handling system is in a folded configuration relative to the deployed configuration corresponding to the working mode.

[0063] The processing unit 10 is thus configured to operate the machine in two distinct modes. The two distinct modes include a so-called working mode in which the handling system 4 is deployed, and a so-called transport mode in which the handling system 4 is folded.

[0064] Thus, in transport mode (movement), the lifting structure 5 is in a folded configuration (so that the machine is more stable than in the deployed configuration of the lifting structure). In this transport mode, the maximum permissible value of the controlled travel speed Vtcmax varies according to the measured angle of inclination A of the chassis, following a first curve ([Fig.3]).

[0065] In working mode, the lifting structure 5 is in a deployed configuration (so that the machine is less stable than in the folded configuration of the lifting structure). In this working mode, the maximum permissible value of the controlled travel speed Vwcmax varies as a function of the measured tilt angle A of the chassis according to a second curve ([Fig.3]) according to which the threshold value of the tilt angle Awmax for which the permissible speed is zero in said working mode, is less than the corresponding threshold value of the tilt angle Atmax defined in transport mode.

[0066] In other words, the value of the tilt angle Awmax for which the value of the maximum speed Vwcmax is zero in working mode is less than the value of the tilt angle Atmax for which the value of the maximum speed Vtmax is zero in transport mode.

[0067] In working mode, the maximum permitted value of the travel speed The command speed is zero for the maximum tilt angle Awmax, whereas in transport mode, for this same tilt angle Awmax, the maximum permissible travel speed Vtl, corresponding to this tilt angle Awmax, is non-zero. This allows, when switching the machine from transport mode to working mode, for it to be moved preferably to an area where the chassis tilt angle is less than the tilt angle Awmax.

[0068] In other words, when in working mode the chassis has reached the limit angle of inclination which prevents movement of the machine on the ground, the machine can return to transport mode by commanding the handling system to switch to the folded configuration, to allow the machine to move and allow it to return to an area of ​​the ground for which the inclination of the chassis is less than the threshold value of inclination defined in working mode in order to be able to return to working mode by commanding the handling system to switch to the deployed configuration.

[0069] Preferably, the machine is equipped with a position sensor (length or angle) allowing the configuration (the arrangement in space) of the handling system, and possibly of the turret when present, to be determined, and thus the corresponding transport or working mode.

[0070] When the vehicle can no longer be moved on the ground in working mode because the chassis angle has reached the maximum angle Awmax, the transport mode remains activatable by folding the lifting structure, to allow the operator to move the machine on a less inclined ground.

[0071] Control Law

[0072] The control law is detailed below in relation to [Fig.3].

[0073] In absolute value and with respect to the horizontal, an angular range [0; Awmax] of inclination of the chassis 2 is defined with Awmax a value strictly greater than 0°, preferably between 2° and 6°, for example 5°.

[0074] The maximum permissible value of the controlled speed Vwcmax in working mode to which the machine movement control is limited and which is defined by the processing unit 10, decreases, preferably from a given angle AW1, until it reaches preferably a reduced speed value Vw0_reduced (which may correspond to a percentage of the speed VwO which may vary for example between 0% and 20%), then a zero speed when the measured angle of inclination A of the chassis 2 reaches the threshold value of the angle of inclination Awmax.

[0075] The decrease in the maximum permissible value of the controlled speed Vwcmax in working mode preferably occurs along a constant slope, down to the maximum angle value. The slope can be expected to have an absolute value between 0.4 and 0.6 km / h per degree.

[0076] In absolute value and with respect to the horizontal, an angular range [0; Atmax] of inclination of the chassis 2 is also defined, with Atmax a value strictly greater than Awmax, preferably between 18 and 25°, for example 20°.

[0077] The maximum allowed value for the controlled speed Vtcmax in transport mode to which the machine movement control is limited and which is defined by the processing unit 10, decreases, preferably from a given angle Atl, until it reaches preferably a reduced speed value Vt0_reduced (which may correspond to a percentage of the speed VtO which may vary for example between 0% and 20%), then a zero speed when the measured angle of inclination A of the chassis 2 reaches the threshold value of the angle of inclination Atmax.

[0078] It can be predicted that Atl is greater than Awl.

[0079] The decrease in the maximum permissible value of the controlled speed Vtcmax preferably occurs along a constant slope, down to the maximum angle value Atmax. The slope can be expected to have an absolute value between 3 and 6 km / h per degree.

[0080] The maximum angle value Atmax of said angular range is greater than the maximum angle value Awmax to allow the machine, when it can no longer move on the ground due to its inclination in working mode, to switch from working mode to transport mode by commanding the switching to the folded (or retracted or lowered) configuration of the handling system (in particular the lifting structure) to improve the stability of the machine and thus allow the machine to be moved on the ground to reposition it in an area where the inclination of the machine falls below the maximum angle value Awmax defined for working mode.

[0081] Each maximum permissible speed value Vwcmax and Vtcmax can be stored in a memory of the processing unit 10.

[0082] According to one embodiment, when the operator acts on a speed control element 11A, for example a joystick on the control panel 11 of the platform 7, bringing it into a position corresponding to a given percentage, denoted X%, of the travel of this speed control element, then the processing unit 10 commands the ground movement of the machine at a commanded speed whose value is equal to X% of the maximum authorized value Vwmax or Vtmax (depending on the working or transport mode in which the machine is located).

[0083] Depending on the work or transport mode, from Awl or Atl, the maximum authorized speed Vwcmax or Vtcmax decreases as the angle of inclination increases until it becomes zero when the angle Awmax or Atmax is reached.

[0084] As mentioned above, when the angle A of inclination of the chassis 2 reaches the maximum value Awmax, so that the machine comes to a stop, the unit of Processing method 10 is configured to allow the machine to switch from working mode to transport mode, enabling it to be moved. Specifically, the machine can be moved to a ground area where the inclination angle of the chassis 2 falls below the maximum value Awmax defined for working mode (see the example control law in [Fig. 3]). The operator can then switch back to working mode.

[0085] Switching to transport mode allows the operator to get out of the standstill situation which results from having reached the maximum tilt angle in working mode. The operator can control the switch between transport and work modes from the platform's control panel.

[0086] It can be foreseen that the control law of the maximum authorized value for the controlled speed as a function of the angle of inclination for the transport mode, includes a plateau (constant maximum authorized speed value equal to VtO) for the part [0 ; Atl] of the range [0 ; Atmax], with Atl strictly less than Atmax, Atl being for example equal to 17° and the plateau speed VtO being for example equal to 5 km / h.

[0087] It can be foreseen that the control law of the maximum allowed value for the controlled speed as a function of the angle of inclination for the working mode, includes a plateau (constant maximum allowed speed value equal to VwO) for the part [0 ; Awl] of the range [0 ; Awmax], with Awl strictly less than Awmax, Awl being for example equal to 3° and the plateau speed VwO being for example equal to 0.7 km / h.

[0088] Additional aspects

[0089] According to one embodiment, the processing unit 10 is configured to modify the maximum permissible value of the controlled speed (in working mode and / or in transport mode) also according to the determined value of the steering angle of the wheels (steering angle) so that the operators in the platform do not encounter a problem due to a turn that is too sharp.

[0090] According to one embodiment, the drive system for moving the chassis on the ground includes an electric motor, and the processing unit 10 is configured to modify the maximum permissible value of the controlled speed also according to the determined temperature value of the electric motor. Such consideration of the temperature helps to protect the service life of the electric motor.

[0091] Processing unit

[0092] The processing unit is presented for example in the form of a processor and a data memory in which computer instructions executable by said processor are stored, or in the form of a microcontroller.

[0093] In other words, the functions and steps described can be implemented in the form of a computer program or via hardware components (e.g., programmable gate arrays). In particular, the functions and steps performed by the processing unit, especially for controlling the drive of the ground movement system and the handling system, can be carried out by instruction sets or computer modules implemented in a processor or controller, or by dedicated electronic components or components of the type of field-programmable gate array (FPGA) or application-specific integrated circuit (ASIC).It is also possible to combine computer and electronic components.

[0094] The processing unit is thus an electronic and / or computer unit. When it is specified that said unit is 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 carried out and / or that the unit includes corresponding electronic components.

[0095] Process

[0096] An example of a method for controlling a handling machine as proposed above is shown below in connection with [Fig.4].

[0097] In step 410, the operator commands the at least partial deployment of the handling system so that the processing unit determines that the machine is in working mode. It can be anticipated that, from a certain level of deployment, determined by a position sensor system (for example, an angular position sensor) of the handling system elements, the processing unit determines that the machine is in working mode. Similarly, it can be anticipated that, from a certain level of retraction, determined by said position sensor system of the handling system element(s) and / or the turret when present, the processing unit determines that the machine is in transport mode.

[0098] In step 420, the processing unit 10 measures the angle of inclination of the chassis relative to the horizontal. As explained previously, in said working mode, a maximum permissible value for the controlled travel speed corresponds to the measured angle of inclination. In the case where the machine includes a manual travel speed control device 1 IA, when the speed control device is moved to X% of its available travel stroke, the value of the speed controlled by the processing unit can be defined as being equal to X% of the maximum permissible value for the controlled travel speed (which is defined according to the chassis angle).

[0099] At step 430, the processing unit thus commands the speed of movement of the machine to a value less than or equal to the maximum authorized value corresponding to the angle of inclination measured according to the instructions received from the speed control device.

[0100] Starting from a given machine tilt angle, which may be zero, as the machine tilt angle increases, the maximum permissible value for the controlled speed decreases until it reaches zero. Thus, when, at step 440, the machine tilt angle reaches a maximum tilt value defined for the working mode, movement of the machine is prevented in that mode.

[0101] At step 450, the operator commands the handling system to retract to return to transport mode, for which movement of the machine is permitted for an angular tilt range which includes the maximum tilt value defined for the working mode.

[0102] At step 460, the machine is moved in transport mode to an area where the angle of inclination falls below the maximum inclination value defined for working mode. At step 470, the operator can then command the deployment of the handling system again to return to working mode.

[0103] It can be provided that the processing unit controls the ground movement system with a controlled speed value that is a percentage of the maximum allowed value, said percentage being equal to the percentage of the stroke of the ground movement speed control element of the machine.

[0104] The maximum permitted travel speed is thus adapted according to the measured chassis inclination value, to allow for a progressive deceleration of the machine as the chassis angle increases, which allows the machine to be slowed down safely until it comes to a stop, and thus improves the stability control of the machine.

[0105] This results in a gradual, rather than abrupt, stop of the machine, taking into account the increasing inclination of the chassis. The gradual reduction of the maximum authorized speed limits the risk of tipping that could result from a sudden stop.

[0106] In other words, the processing unit safely adjusts the maximum permitted travel speed when the inclined chassis is close to a limit value, specifically by providing a gradual rather than abrupt decrease in the maximum permitted travel speed as a function of the chassis's angle of inclination. The dynamic effects and elasticity of the structure are reduced, which limits the machine's inertia and thus allows for better compliance with the inclination limit value. when the machine stops.

[0107] The invention is not limited to the embodiments illustrated in the drawings.

[0108] Furthermore, the term "including" does not exclude other elements or steps. In addition, features or steps that have been described with reference to one of the embodiments set out above may also be used in combination with other features or steps from other embodiments set out above.

Claims

Demands

1. Machine (1) for handling loads or persons, comprising: - a rolling chassis (2); - a motorized drive system (12) for moving the chassis (2) on the ground; - a chassis tilt sensor system (19) allowing measurement of a chassis tilt angle (A); - a handling system (4) which is capable of taking different configurations in space relative to the chassis; - a processing unit (10) enabling the motorized drive system (12) to be controlled when the chassis is moving on the ground; - a speed control system (11A), such as a joystick, allowing the transmission to the processing unit (10) of a ground travel speed instruction of the machine; - a control system, such as a joystick, for the handling system to control its configuration in space; the processing unit (10) being configured to operate the machine in two distinct modes, comprising: - a so-called working mode in which the handling system (4) is in a first spatial configuration called the working mode, for example deployed vertically, and - a mode called transport mode for which the handling system (4) is in a second spatial configuration, for example folded or retracted, for which the machine exhibits greater stability than in said working configuration of the handling system (4) of the machine; characterized in that the processing unit (10) is configured to, in working mode, define a maximum permissible value of controlled speed (Vwcmax) for the ground displacement of the machine which is a function of the measured angle of inclination (A) of the chassis, and which decreases as the angle of inclination (A) increases from a given value of inclination (Awl), which may be zero, towards a maximum angle value (Awmax).

2. Machine according to claim 1, wherein the processing unit (10) is configured to, in transport mode, define a maximum permissible value of controlled speed (Vtcmax) for the ground displacement of the machine which is non-zero within a range given angular value which includes said maximum angle value (Awmax) defined for the working mode.

3. Machine according to claim 1 or 2, wherein the processing unit (10) is configured to, in transport mode, define a maximum permissible value of controlled speed (Vtcmax) for the ground displacement of the machine which is a function of the measured angle of inclination (A) of the chassis, and which decreases as the angle of inclination (A) increases from a given value of inclination (Atl), which may be zero, towards a maximum angle value (Atmax).

4. Machine according to claim 3, wherein said maximum angle value (Atmax) in transport mode is greater than the maximum angle value (Awmax) in working mode.

5. Machine according to any one of the preceding claims, wherein, in working mode, when the angle (A) of inclination of the chassis (2) reaches the maximum value (Awmax), so that the machine comes to a standstill, the processing unit (10) is configured to allow the machine to be switched from working mode to transport mode by control of the handling system, the processing unit being configured so that, when the machine is in transport mode, it allows the vehicle to move on the ground up to a maximum angle of inclination of the chassis which is greater than the maximum angle of inclination of the chassis defined in working mode, so as to allow the machine to return to an area of ​​the ground for which the angle of the chassis is less than the maximum value (Awmax) of inclination of the chassis (2) defined in working mode.

6. Machine according to any one of the preceding claims, wherein the speed control system (11A) includes a manual speed control member actuable over a given stroke, such as a joystick, the processing unit (10) is configured to, in response to the actuation by the operator of said manual control member, control the motorized drive system (12) in moving the chassis on the ground, to move the machine according to a controlled speed value which is less than or equal to said maximum permissible value (Vwcmax) in working mode and which is defined according to the position of the manual control member.

7. A machine according to claim 6, wherein, following the movement of the manual control member for controlling the speed, the processing unit sets the value of the controlled speed by multiplying the maximum permissible value of the controlled speed by the ratio between the stroke traveled by the manual control element and the total available stroke of said manual control element.

8. Machine according to any one of the preceding claims, wherein the processing unit (10) is configured to, over the angular range [0; Awl] of chassis tilt, the value Awl being less than the maximum angle value Awmax, set the maximum permissible value of controlled speed (Vwcmax) for the ground displacement of the machine in working mode, as being equal to a constant value (VwO).

9. Machine according to any one of the preceding claims, wherein the handling system (4) carried by the chassis comprises a set of arms (6) articulated together and a platform (7) coupled to said set of arms (6), said set of arms (6) being capable of taking a deployed height configuration, according to which the working mode is activated, and a folded configuration according to which the transport mode is activated.

10. Machine according to any one of the preceding claims, wherein the machine comprises a turret (3) mounted rotatably on the chassis (2) about an axis orthogonal to the ground support plane of the machine's wheels, the handling system (4) being carried by the turret (3).

11. A method for controlling a machine according to any one of the preceding claims, said method comprising the following steps: - controlling (410) the handling system, in the direction of extending or deploying an element of the handling system, so that the processing unit determines that the machine is in working mode; - decreasing the maximum permissible value (Wcmax) for the controlled travel speed of the machine as the measured tilt angle (420) of the chassis increases; - controlling (430) the travel speed of the machine to a value less than or equal to the maximum permissible value (Wcmax); - reaching (440) the maximum tilt angle (Awmax) of the chassis defined for working mode such that the maximum permissible value for the controlled travel speed is zero; - controlling (450) the handling system (4), in the direction of retracting or folding an element of the handling system, so that that the processing unit determines that the machine is in transport mode; - movement (460) of the machine in said transport mode to reach an area for which the measured angle of inclination of the chassis falls below the maximum inclination value defined for the working mode; - preferably, control (470) of the handling system to switch back to working mode.

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