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 authorized speed of which is limited as a function of the angle of inclination (A) of the machine, such that, over at least part of an angular range [0; Awmax], the maximum authorized set speed decreases until it reaches a zero speed value when the measured angle of inclination of the chassis reaches the maximum angle value Awmax of said angular range. Figure for abstract: Fig.3

Description

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

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

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

[0003] Such a machine usually comprises a rolling chassis equipped with a power unit. The chassis may receive a turret which carries, by means of a movement mechanism, a lifting structure, such as a lifting arm system, at the end of which is coupled a work platform, in 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 ground movement of the machine when the chassis tilt limit is reached so as not to exceed the tilt limit and risk the machine tipping over. However, it is noted that there is a risk of tipping over when the machine is stopped.

[0006] It is understood that a stability problem may also arise for other types of handling machines, such as telescopic arm trucks, in particular when the handling system carried by the chassis of the machine, which for example comprises a telescopic arm, is in an extended, 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 aim of the present invention is to propose a new machine and a new corresponding method making it possible to overcome all or part of the problems set out above. Summary of the invention

[0008] To this end, the invention relates to a load or person, including: - a rolling chassis; - a motorized system for driving the chassis on the ground; - a chassis tilt sensor system for measuring a chassis tilt angle; - a handling system which is capable of taking different configurations in space relative to the chassis; - a processing unit for controlling the motorized drive system for moving the chassis on the ground; - a speed control system, such as a joystick, for transmitting to the processing unit an instruction for the ground travel speed of the machine; - a control system, such as a joystick, of the handling system to control its configuration in space; the processing unit being configured to operate the machine in two distinct modes, comprising: - a mode called work mode for which the handling system is in a first spatial configuration called work, 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 said work configuration of the handling system of the machine; the processing unit is configured to, in work mode, define a maximum authorized value of commanded speed for the ground movement of the machine which is a function of the measured tilt angle of the chassis, and which decreases when the tilt angle increases from a given tilt value, 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 may be a maximum tilt threshold (i.e. a lateral inclination threshold) or a longitudinal inclination threshold. It may also be provided that the inclination threshold comprises a combination of longitudinal and lateral inclination threshold. The movement of the machine on the ground comprises the forward and backward movement of the machine.

[0010] The progressive reduction of the maximum permitted ground travel speed of the handling machine as the angle of inclination of the chassis increases makes it possible to slow down the ground travel of the machine before reaching the maximum permitted angle of inclination of the chassis. Slowing down the machine makes it possible to effectively anticipate stopping to avoid a sudden movement of the machine which could risk destabilizing the machine.

[0011] Conversely, in the solutions of the state of the art, the stop is carried out abruptly when the threshold tilt angle is reached, without anticipation, which risks causing the machine to tip over. Furthermore, it is noted that with the machines of the state of the art, when the maximum authorized threshold of tilt of the chassis is reached and a command to stop movement on the ground is triggered, the maximum authorized threshold of tilt of the chassis is ultimately often exceeded due to the inertia of the machine. This can cause problems of instability and stalling of the rotation of the turret when it is present.

[0012] It will be noted that the processing unit modifies the maximum authorized value of the commanded ground travel speed of the machine as a function of the measured chassis tilt angle, but that the processing unit allows the operator, or a control program in the context of an autonomously driven machine, to act on the control of the ground travel speed of the machine which nevertheless remains limited by said maximum authorized value of the commanded ground travel speed itself defined as a function of the measured chassis tilt angle. In other words, the processing unit sets the maximum value of the commanded speed according to the measured chassis angle: the commanded machine travel speed can then vary between a zero value and said maximum value which has been defined as a function of the measured chassis angle.

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

[0014] In other words, the maximum authorized value of the commanded speed is reduced when the inclination of the chassis exceeds a first inclination value so that it approaches the maximum authorized inclination value, i.e. if, in absolute value, the difference between the measured chassis inclination angle and the maximum authorized inclination value is less than a given threshold value (in other words if the distance or difference between the measured chassis inclination angle and the maximum authorized inclination 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, it can be provided that the processing unit is configured to maintain the maximum authorized value of the commanded speed at a constant value (i.e. a level).

[0015] According to one embodiment, for an angle of inclination of the chassis which progresses from a first given inclination value towards the maximum authorized inclination value, the maximum authorized value of the commanded speed evolves according to a decreasing slope, for example a decreasing slope of constant value, preferably without depending on external conditions (other than conditions impacting the chassis angle). For 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 is reflected in the inclination of the chassis relative to the horizontal plane.

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

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

[0018] According to one embodiment of the invention, the processing unit is configured to, in transport mode, define a maximum authorized value of commanded 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 work 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 commanded speed for the movement on the ground of the machine which is a function of the measured angle of inclination of the chassis, and which decreases when the angle of inclination increases from a given inclination value, 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 work mode.

[0021] According to one embodiment of the invention, in work mode, when the chassis tilt angle reaches the maximum value, so that the machine comes to a standstill, the processing unit is configured to allow the machine to switch from work mode to transport mode by command from the handling system, the processing unit being configured to, when the machine is in transport mode, authorize the vehicle to move on the ground up to a maximum chassis tilt angle which is greater than the maximum chassis tilt angle defined in work 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 work mode.

[0022] According to an embodiment of the invention, in which the speed control system comprises a manual speed control member operable over a given stroke, such as a joystick, the processing unit is configured to, in response to the driver actuating said manual control member, control the motorized drive system for moving the chassis on the ground, to move the machine according to a commanded speed value which is less than or equal to said maximum value authorized in work mode and which is defined as a function of the position of the manual control organ.

[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 authorized value of the controlled speed by the ratio between the traveled stroke of 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 inclination of the chassis, the value Awl being less than the maximum angle value Awmax, define the maximum authorized value of commanded speed for the movement on the ground of the machine in work 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 together and a platform coupled to said set of arms, said set of arms being capable of taking a deployed configuration in height, according to which the work 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 rotatably mounted on the chassis around an axis orthogonal to the ground support plane of the wheels of the machine, the handling system being carried by the turret.

[0027] The invention also relates to a method of 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 deployment or output of an element of the handling system, so that the processing unit determines that the machine is in work mode; - decrease in the maximum permissible value for the commanded speed of movement of the machine when the measured tilt angle of the chassis increases; - control of the machine's travel speed to a value less than or equal to the maximum authorized value; - reaching the maximum chassis tilt angle defined for work mode so that the maximum value permitted for the commanded travel speed is zero; - control of the handling system, in the sense of a withdrawal 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 tilt angle of the chassis falls below the maximum tilt value defined for the work mode; - preferably, control of the handling system to return to work mode.

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

[0029] Other characteristics and advantages of the invention will emerge from the following description, which is purely illustrative and non-limiting and must be read in conjunction with the appended drawings, in which:

[0030] - [Fig.l] [Fig.l] is a schematic view of a handling machine according to a embodiment of the invention, the chassis of the machine having a first inclination value (which may correspond to the angle of inclination of the ground relative 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 inclination value and the maximum authorized value of the commanded ground travel speed is limited to a first given value;

[0031] - [Fig.2] [Fig.2] is a schematic view of the machine [Fig.l], the chassis of the machine having a second inclination value which is greater than the first inclination value of [Fig.l], 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 giving, for each of two modes of func operation of the machine, namely a working mode and a transport mode, a control law of the maximum authorized value of the commanded ground travel 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.l], the maximum authorized value of the commanded speed being, in absolute value, preferably constant up to a certain angle of inclination of the chassis, then decreasing until reaching a zero value for the maximum authorized angle of inclination of the chassis;

[0033] - [Fig.4] [Fig.4] is a flowchart showing the steps of a control method of a handling machine according to one 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. Like numerals refer to like elements throughout the drawings. However, the invention may be embodied in many different forms and should not be construed as being limited to the embodiments set out here.

[0035] A reference throughout the specification to "an embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment is included in at least one embodiment of the present invention. Thus, the occurrence of the phrase "in an embodiment" at various locations 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 machine 1 for handling loads or people 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 handling machine stops moving on the ground, thanks to a reduction in the maximum authorized value of the commanded speed of movement on the ground 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 basket type is shown, allowing work to be carried out by lifting people.

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

[0040] Thus the remainder of the description given in the case of a nacelle 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 nacelle 1 comprises a rolling chassis 2 equipped with a motor system 12 for driving the chassis 2 on the ground. The motor system may be of the thermal or electric type.

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

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

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

[0045] The platform 7 is equipped with a control console 11. The control console 11 comprises a first control member 11A, such as a joystick, which makes it possible to control the movement of the machine on the ground, and a second control member, such as a joystick, which makes it possible to control the handling system and in particular the deployment and folding of the lifting structure. It is possible to provide for the first control member and the second control member to be produced by the same member that can be actuated differently depending on the desired function or two separate members.

[0046] The control console 11 thus allows the operator to transmit to the processing unit 10 instructions for controlling the movement of the chassis on the ground 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 can be articulated relative to the chassis (via the turret 3 if applicable). The elements 67, 68, 69 may be considered as part of the set of arms 6.

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

[0050] The cylinder system may be of the hydraulic or electric type. In the case of a hydraulic cylinder system, a hydraulic circuit system (not shown) is used to power the hydraulic cylinder system. The hydraulic circuit system usually comprises a circuit for powering the cylinder system and an oil pressurization system, such as a pump, actuated by a motor. Said motor may be wholly or partly shared with a motor of the ground-based drive system or be a separate motor. The processing unit is used to control the hydraulic circuit system to control the power supply to the cylinder system.

[0051] Chassis tilt

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

[0053] Generally speaking 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.l]) then a second value A2 ([Fig.2]) greater than Al, the maximum authorized value of the commanded speed V2 defined for the angle A2 is less than the maximum authorized value of the commanded speed VI defined for the angle Al.

[0054] As recalled above, the machine comprises a processing unit 10 for controlling the drive system 12 in movement of the chassis on the ground, to move the machine according to a commanded speed. A commanded speed signal can be supplied to the processing unit by the actuation of the control member 1 IA of the control console 11, such as a joystick, connected to the processing unit 10. Preferably, the signal is representative of the actuation travel of the member. It can thus be provided that a movement of X% of the member over its available travel is interpreted by the processing unit 10 as a speed command at X% of the maximum authorized value of the speed.

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

[0056] The angle of inclination of the chassis may comprise the angle, called the lateral inclination angle, which a normal to the ground support plane of the wheels of the machine forms 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 a variant, the angle of inclination of the chassis may comprise the angle, called the longitudinal angle of inclination, which a normal to the ground support plane of the wheels of the machine forms with the vertical in a plane which passes through the vertical and a longitudinal axis of the machine (i.e. a front-rear movement axis 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 support plane of the wheels of the machine and which passes between the two rear wheels and between the two front wheels of the vehicle.

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

[0059] Operating modes

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

[0061] The processing unit may be configured to determine that the machine is in work 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 work 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 work mode.

[0063] The processing unit 10 is thus configured to operate the machine in two distinct modes. The two distinct modes comprise a mode called work mode for which the handling system 4 is deployed, and a mode called transport mode for 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 authorized value of the commanded travel speed Vtcmax changes as a function of the measured angle of inclination A of the chassis according to a first curve ([Fig.3]).

[0065] In work 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 work mode, the maximum authorized value of the commanded travel speed Vwcmax changes as a function of the measured tilt angle A of the chassis according to a second curve ([Fig. 3]) according to which the tilt angle threshold value Awmax for which the authorized speed is zero in said work mode, is lower than the corresponding tilt angle threshold value Atmax defined in transport mode.

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

[0067] In work mode, the maximum permitted value of the travel speed commanded is zero for the value of the tilt angle Awmax while, in transport mode, for this tilt angle value Awmax, the maximum authorized value of the travel speed Vtl, corresponding to this tilt angle value Awmax, is non-zero. This allows, when switching the machine from transport mode to work mode, to move it preferably in an area for which the tilt angle of the chassis is less than the tilt angle value Awmax.

[0068] In other words, when in work mode, the chassis has reached the limit tilt angle which prevents the machine from moving on the ground, the machine can return to transport mode by controlling the handling system to switch to the folded configuration, to authorize the machine to move and to return to an area of the ground for which the tilt of the chassis is less than the threshold tilt value defined in work mode in order to be able to return to work mode by controlling the handling system to switch to the deployed configuration.

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

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

[0071] Control law

[0072] The control law is detailed below in connection with [Fig.3].

[0073] In absolute value and relative 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 authorized value of the commanded speed Vwcmax in work mode to which the movement command of the machine is limited and which is defined by the processing unit 10, decreases, preferably from a given angle AW1, until it preferably reaches a reduced speed value Vw0_reduit (which can correspond to a percentage of the speed VwO which can 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 inclination angle Awmax.

[0075] The decrease in the maximum authorized value of the commanded speed Vwcmax in working mode is preferably carried out according to a constant slope, up to the maximum angle value. It can be provided that the slope is in absolute value between 0.4 and 0.6 km / h per degree.

[0076] In absolute value and relative 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 authorized value for the commanded speed Vtcmax in transport mode to which the movement command of the machine is limited and which is defined by the processing unit 10, decreases, preferably from a given angle Atl, until it preferably reaches a reduced speed value Vt0_reduit (which can correspond to a percentage of the speed VtO which can vary for example between 0% and 20%), then a zero speed the measured inclination angle A of the chassis 2 reaches the inclination angle threshold value Atmax.

[0078] Atl can be predicted to be superior to Awl.

[0079] The decrease in the maximum authorized value of the commanded speed Vtcmax is preferably carried out according to a constant slope, up to the maximum angle value Atmax. It can be provided that the slope is in 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 work mode, to switch from work mode to transport mode by controlling the switch 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 move on the ground to reposition it in an area for which the inclination of the machine returns below the maximum angle value Awmax defined for the work mode.

[0081] Each maximum authorized value of speed 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 control member 11A of the movement speed, for example a joystick of the control panel 11 of the platform 7, by bringing it into a position corresponding to a given percentage, noted X%, of the movement travel of this speed control member, then the processing unit 10 controls the movement on the ground of the machine at a commanded speed whose value is equal to X% of the maximum authorized value Vwmax or Vtmax (depending on the work 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 thus decreases as the angle of inclination increases until it becomes zero when the angle Awmax or Atmax is reached.

[0084] As recalled above, when the angle A of inclination of the chassis 2 reaches the maximum value Awmax, so that the machine comes to a standstill, the unit of processing 10 is configured to allow the machine to switch from work mode to transport mode in order to allow the machine to be moved. In particular, the machine can be moved to an area of the ground for which the tilt angle of the chassis 2 becomes lower than the maximum value Awmax defined for work mode (see the example control law in [Fig.3]). The operator can then return to work mode.

[0085] Switching to transport mode allows the operator to exit the stopping situation that results from reaching the maximum tilt angle in work mode. The operator can control the transition to transport or work mode from the platform control panel.

[0086] It can be provided that the control law of the maximum authorized value for the commanded speed as a function of the angle of inclination for the transport mode, includes a level (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 level speed VtO being for example equal to 5 km / h.

[0087] It can be provided that the control law of the maximum authorized value for the commanded speed as a function of the angle of inclination for the working mode, includes a level (constant maximum authorized 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 level 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 authorized value of the commanded speed (in work mode and / or in transport mode) also as a function of the determined value of the steering angle of the wheels (steering angle) so that the operators in the nacelle do not encounter a problem due to a turn that is too tight.

[0090] According to one embodiment, the system for driving the chassis on the ground comprising an electric motor, the processing unit 10 is configured to modify the maximum authorized value of the commanded speed also as a function of the determined value of the temperature of the electric motor. Such consideration of the temperature makes it possible 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 operated by the processing unit, in particular for controlling the motorization of the ground movement system and controlling the handling system, can be carried out by instruction sets or computer modules implemented in a processor or controller or be carried out by dedicated electronic components or components of the programmable logic circuit type (or FPGA which is the acronym for field-programmable gate array, which literally corresponds to in-situ programmable gate array) or of the application-specific integrated circuit type (or ASIC which is the acronym for application-specific integrated circuit, which literally corresponds to application-specific integrated circuit).It is also possible to combine computer parts and electronic parts.

[0094] The processing unit is thus an electronic and / or computer unit. When it is specified that said unit is configured to carry out a given operation, this means that the unit comprises computer instructions and the corresponding execution means which make it possible to carry out said operation and / or that the unit comprises corresponding electronic components.

[0095] Method

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

[0097] In step 410, the operator controls the at least partial deployment of the handling system so that the processing unit determines that the machine is in work mode. It can be provided that from a certain level of deployment, determined by a position sensor system, for example angular position, of elements of the handling system, the processing unit determines that the machine is in work mode. Similarly, it can be provided that from a certain level of folding, determined by said position sensor system of element(s) of the handling system and / or of the turret when it is 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 authorized value for the commanded movement speed corresponds to the measured angle of inclination. In the case where the machine comprises a member 1 IA for manual control of the movement speed, when the speed control member is moved to X% of its available movement travel, the value of the speed commanded by the processing unit can be defined as being equal to X% of the maximum authorized value for the commanded movement speed (which is defined according to the frame angle).

[0099] In step 430, the processing unit thus controls 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 member.

[0100] From a given tilt angle value of the machine, which may be zero, when the tilt angle of the machine increases, the maximum value allowed for the commanded speed decreases until it reaches a zero value. Thus, when in step 440, the tilt angle of the machine has reached a maximum tilt value defined for the work mode, the movement of the machine is prevented in this mode.

[0101] In step 450, the operator commands the withdrawal of the handling system to return to transport mode, for which the movement of the machine is permitted for an angular inclination range which includes the maximum inclination value defined for the work mode.

[0102] In step 460, the machine is moved in transport mode into an area for which the tilt angle returns below the maximum tilt value defined for the work mode. In step 470, the operator can then again command the deployment of the handling system to return to work mode.

[0103] It may be provided that the processing unit controls the ground movement system with the commanded speed value being a percentage of the maximum authorized value, said percentage being equal to the percentage of the travel of the ground movement speed control member of the machine.

[0104] The maximum authorized travel speed is thus adapted according to the measured chassis inclination value, to enable a progressive slowing of the machine as the chassis angle increases, which makes it possible to slow the machine down to a safe stop, and thus to improve the stability control of the machine.

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

[0106] In other words, the processing unit safely adapts the maximum authorized travel speed when the inclined chassis is close to a limit value, in particular by providing a gradual and not abrupt reduction in the maximum authorized travel speed as a function of the angle of inclination of the chassis. The dynamic effects and the elasticity of the structure are reduced, which limits the inertia effect of the machine and thus makes it possible to better respect the limit value of inclination. when stopping the machine.

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

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

Claims

Claims

1. Machine (1) for handling loads or people, comprising: - a rolling chassis (2); - a motorized drive system (12) for moving the chassis (2) on the ground; - a sensor system (19) for tilting the chassis (2) making it possible to measure an angle (A) of tilt of the chassis (2); - a handling system (4) which is capable of taking different configurations in space relative to the chassis; - a processing unit (10) for controlling the motorized drive system (12) in movement of the chassis on the ground; - a speed control system (11A), such as a joystick, making it possible to transmit to the processing unit (10) an instruction for the ground movement speed of the machine; - a control system, such as a joystick, of 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 mode called work mode for which the handling system (4) is in a first spatial configuration called work, for example deployed at height, 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 has 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 work mode, define a maximum authorized value of commanded speed (Vwcmax) for the movement on the ground of the machine which is a function of the measured angle of inclination (A) of the chassis, and which decreases when the angle of inclination (A) increases from a given inclination value (Awl), which may be zero, towards a maximum angle value (Awmax).

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

3. Machine according to claim 1 or 2, in which the processing unit (10) is configured to, in transport mode, define a maximum authorized value of commanded speed (Vtcmax) for the ground movement of the machine which is a function of the measured angle of inclination (A) of the chassis, and which decreases when the angle of inclination (A) increases from a given inclination value (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 work mode.

5. Machine according to any one of the preceding claims, in which, in work 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 switch from work mode to transport mode by control of the handling system, the processing unit being configured to, when the machine is in transport mode, authorize the movement on the ground of the vehicle up to a maximum angle of inclination of the chassis which is greater than the maximum angle of inclination of the chassis defined in work 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 work mode.

6. Machine according to any one of the preceding claims, in which the speed control system (11A) comprises a manual speed control member operable over a given stroke, such as a joystick, the processing unit (10) is configured to, in response to the driver actuating said manual control member, control the motorized drive system (12) in movement of the chassis on the ground, to move the machine according to a commanded speed value which is less than or equal to said maximum authorized value (Vwcmax) in work mode and which is defined as a function of the position of the manual control member.

7. Machine according to claim 6, in which, following the movement of the manual control member to control the speed, the processing unit defines the value of the commanded speed by multiplying the maximum permitted value of the speed controlled by the ratio between the stroke traveled by the manual control member and the total available stroke of said manual control member.

8. Machine according to any one of the preceding claims, in which the processing unit (10) is configured to, over the angular range [0; Awl] of inclination of the chassis, the value Awl being less than the maximum angle value Awmax, define the maximum authorized value of commanded speed (Vwcmax) for the ground movement of the machine in work mode, as being equal to a constant value (VwO).

9. Machine according to any one of the preceding claims, in which 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 configuration in height, according to which the work 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, in which the machine comprises a turret (3) rotatably mounted on the chassis (2) around an axis orthogonal to the ground support plane of the wheels of the machine, the handling system (4) being carried by the turret (3).

11. Method for controlling a machine according to any preceding claim, said method comprising the following steps: - controlling (410) the handling system, in the direction of deployment or exit of an element of the handling system, so that the processing unit determines that the machine is in work mode; - decreasing the maximum authorized value (Wcmax) for the commanded speed of movement of the machine when the measured tilt angle (420) of the chassis increases; - controlling (430) the speed of movement of the machine to a value less than or equal to the maximum authorized value (Wcmax); - reaching (440) the maximum tilt angle (Awmax) of the chassis defined for the work mode so that the maximum authorized value for the commanded speed of movement is zero; - controlling (450) the handling system (4), in the direction of withdrawal or retraction of an element of the handling system, so that the processing unit determines that the machine is in transport mode; - moving (460) the machine in said transport mode to reach an area for which the measured tilt angle of the chassis falls below the maximum tilt value defined for the work mode; - preferably, control (470) of the handling system to return to work mode.

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