Method for controlling an aerial work platform, in particular a scissor lift, and associated aerial work platform

Abstract

Method for controlling an aerial work platform, in particular a scissor lift, and associated aerial work platform. This method for controlling an aerial work platform includes a first step (101), while the wheels are not rotating, in which a first characteristic quantity of the aerial work platform's states is measured, the first quantity being the height of a basket of the platform, and at least a second characteristic quantity of the aerial work platform's states is measured, the first value forming, with at least one second value measured for each second quantity, a group of values. Then, in a second step (102), it is evaluated whether each group of values ​​is included in an permitted (Z1) or prohibited (Z2) zone of a chart (110) associated with that group of values. Then, in a third step (103), the movement of the aerial work platform on the ground is authorized or not based on the evaluation in the second step (102).Figure for the abbreviation: Figure 4.

Description

Title of the invention: Method for controlling an aerial work platform, in particular a scissor lift, and associated aerial work platform

[0001] The present invention relates to a method of controlling an aerial work platform, in particular a scissor lift, as well as an aerial work platform implementing such a control method.

[0002] A mobile personnel lifting platform, also simply called a "lifting platform," comprises a chassis mounted on wheels to allow movement of the lifting platform on the ground, a basket—also called a platform—and a basket lifting device, which is interposed between the basket and the chassis to adjust the basket's height relative to the ground. This discussion focuses on lifting platforms that allow the basket to be raised vertically above the chassis when the ground is horizontal. Examples include, but are not limited to, scissor lifts, telescopic lifts, boom lifts, etc.

[0003] The basket, which includes a platform surrounded by a guardrail, is designed to accommodate one or more persons and possibly also loads such as tools or other equipment, materials such as paint, cement, etc.

[0004] In the case of a scissor lift, the lifting device comprises bars that are articulated at their center in a scissor-like fashion. Several of these scissor mechanisms are mounted one above the other by their ends, which are pivotally connected, so that the assembly formed by the articulated bars can fold and extend vertically. The lifting device also includes at least one actuator, generally hydraulic cylinders, which actuates the articulated bars to extend or fold them.

[0005] To allow the basket to be lifted, the ends of the upper bars are connected to pads designed to slide in rails provided under the platform floor, while the ends of the lower bars are connected to pads designed to slide in rails provided on the chassis. The lifting device thus allows the basket to be raised from a lowered position on the chassis to the desired working height, generally by means of one or more hydraulic cylinders, with the basket then in a raised position.

[0006] On aerial work platforms, stability is essential for safety reasons. The height of the basket, as well as the load it supports, the distribution of the load on the platform, etc., are among the elements to be known in order to control this stability and ensure that the operator does not use the aerial work platform beyond the safety conditions.

[0007] In particular, according to current, very conservative practice, when the basket is in the raised working position, if the aerial work platform needs to be moved on the ground, the basket must first be lowered before moving the chassis relative to the ground, and then the basket must be raised back to its raised working position. Furthermore, some machines require the use of outriggers to raise themselves. Moving requires raising the outriggers, moving, and then reattaching the outriggers before raising again. This sequence of operations requires time and energy, which reduces the autonomy of the aerial work platforms, especially when the platforms are electric, which is increasingly the case.

[0008] It is these problems that the invention intends to remedy in particular, by proposing a lifting platform that is easier to operate, more economical, without compromising safety.

[0009] To this end, the invention relates to a method for controlling a lifting platform, in which: • The lifting platform includes wheels and is configured to move on the ground by rotating the wheels, the direction of movement of the lifting platform on the ground being controlled by means of steering the wheels, the lifting platform optionally including an oscillating axle and / or a basket with an extension, • during a first stage, while the wheels are not turning: • A first characteristic quantity of the states of the lifting platform is measured using a first measuring device, the first quantity being the height of the platform basket relative to a lowered position of the basket, so as to obtain a first value, and • at least one second characteristic quantity of the states of the lifting platform is measured, each second quantity being different from the first quantity and being measured using a measuring device, so as to obtain at least one second value,

[0010] the first value forming, with at least one second value measured for each second quantity, a group of values, • In a second step, subsequent to the first step, the following is evaluated: • using a calculator and a nomogram stored in the calculator, each group of values ​​being associated with a respective nomogram and forming coordinates of a point in that nomogram, the nomogram being divided into an authorized zone and a prohibited zone, which is complementary to the authorized zone, • if the group of values ​​measured in the first step is included in the permitted or prohibited zone of the nomogram, • During a third step, subsequent to the second step, the movement of the lifting platform on the ground is authorized or not by means of a controller, depending on the evaluation of the second step.

[0011] Thanks to the invention, it is possible to allow the aerial work platform to move on the ground even when the basket is higher than its lowered position, as long as the platform is in operating conditions that do not compromise its stability, thus saving energy and time. The aerial work platform is therefore easier to operate without compromising safety.

[0012] According to advantageous but not mandatory aspects of the invention, such a control method may incorporate one or more of the following features taken individually or in any technically permissible combination: • During the first step, at least one second characteristic quantity is chosen from: • the mass of a load carried in the basket, • the oscillation angle of an oscillating axle of the lifting platform, • a mass distribution coefficient of the load carried in a basket extension, or • a steering angle of the wheels. • During the first step, at least two second values ​​are measured, which are respectively associated with different second characteristic quantities,

[0013] while the first value forms, with each of the two second values, two groups of values, which are each associated with a respective nomogram,

[0014] that during the second step, it is evaluated whether each group of values ​​is included in the authorization zone or in the prohibition zone of the corresponding nomogram,

[0015] and that during the third step, the movement on the ground of the lifting platform is authorized if each group of values ​​is located in the authorization zone of the corresponding nomogram. • One of the nomograms used during the second step is a conditional nomogram, which includes a first version and a second version, one or the other of the first version or the second version being activated depending on the environment and / or a configuration of the lifting platform. • The first version is activated when the lifting platform is located on a slab-like surface, the slab having a leveled and compacted surface, while the second version is activated when the lifting platform is located on a surface that is not a slab,

[0016] whereas during the second step, the calculator evaluates whether the group of values ​​associated with the conditional abacus is included in the authorization area or in the prohibition area of ​​the activated version of the conditional abacus. • In the authorization area of ​​the second version of the conditional nomogram, each point is uniquely associated with a maximum ground speed instruction for the lifting platform,

[0017] whereas during the third step, the movement authorization includes the maximum movement speed instruction. • The maximum travel speed setting depends on the measured value of the first quantity. • Each group of values ​​includes, in addition to the first value, only one second value, the abacus associated with each group of values ​​forming, in graphical representation, a two-dimensional space.

[0018] The invention also relates to an elevating platform, in particular a scissor lift, comprising: • a chassis supported by wheels, the lifting platform being configured to move on the ground by rotating the wheels, • a basket, configured to receive an onboard load, • a lifting device, which is interposed between the basket and the chassis, so that the height of the basket relative to a lowered position of the basket is adjustable, • a first measuring device, configured to measure a first characteristic quantity of the states of the lifting platform, the first characteristic quantity being the height of the basket, • at least one second measuring device, each second measuring device being configured to measure a second characteristic quantity of a state of the lifting platform, the first and second characteristic quantities being different from each other,

[0019] in which the nacelle is configured to implement the control method according to any one of the preceding claims.

[0020] Advantageously: • the lifting platform includes an axle which is oscillating,

[0021] and / or The basket includes an extension.

[0022] The invention will be better understood, and other advantages thereof will become more apparent in the light of the following description of several embodiments of a method for controlling a lifting platform and of a lifting platform, in accordance with its principle, given solely by way of example and with reference to the accompanying drawings, in which:

[0023] - [Fig. 1] [Fig. 1] is a perspective view of a lifting platform conforming to a first embodiment of the invention;

[0024] - [Fig.2] [Fig.2] represents respectively, on four inserts a), b), c) and d), the aerial work platform of the [Fig.l] in four different configurations and side view;

[0025] - [Fig.3] [Fig.3] is a front view of the lifting platform of [Fig.1], represented in another configuration;

[0026] - [Fig.4] [Fig.4] represents respectively, on two insets a) and b), a diagram synoptic diagram illustrating a method of controlling the lifting platform of the [Fig.1], and an example of a nomogram used by this method;

[0027] - [Fig.5] [Fig.5] represents respectively, on two inserts a) and b), gondolas lifting devices conforming to other embodiments of the invention;

[0028] - [Fig.6] [Fig.6] represents respectively, on two inserts a) and b), abacuses used in control processes conforming to other embodiments of the invention, and

[0029] - [Fig.7] [Fig.7] represents respectively, on two inserts a) and b), abacuses used in control processes conforming to other embodiments of the invention.

[0030] A lifting platform is shown in [Fig. 1]. In the illustrated example, the lifting platform is a scissor lift 10. In an alternative not shown, the lifting platform is of another type, for example a telescopic platform, the principles of the invention described with reference to the scissor lift 10 being transposable to other types of lifting platforms.

[0031] The scissor lift 10 comprises a chassis 12 adapted to rest and move on a surface S by means of connecting elements, generally wheels 14. The scissor lift 10 here comprises two axles 15, which are supported by the wheels 14. Only one axle 15 is shown in [Fig. 3]. The wheels 14 define a preferred direction of movement of the chassis 12 and, by extension, of the scissor lift 10.

[0032] The platform 10 also includes a basket 16 and a lifting device 18 for the basket 16. In the illustrated example, the basket 16 includes a platform 17A, a guardrail 17B, and a controller 17C. The controller 17C is configured to transmit information to a user and to receive commands from that user. By way of non-limiting example, the controller 17C provides a human-machine interface for a user located on platform 17A. For example, controller 17C includes buttons and / or control levers, one or more lights or indicator lights, a display screen, possibly a touch screen, one or more audible warning devices.

[0033] The lifting device 18 includes a set of articulated bars 20 supporting the basket 16, such that the elevation of the basket 16 relative to the chassis 12 is variable and controlled by the set of bars 20. The lifting device 18 also includes an actuator 22, here a hydraulic cylinder, which actuates the bars 80 to control a height H of the platform 16 relative to the chassis 12, and by extension relative to the ground S on which the scissor lift 10 moves. The actuator 22 is, for example, controlled by means of the controller 17C, by a user located on the platform 17A.

[0034] The frame 12 defines a mean plane P12, which is parallel to the ground S. The lifting device 18 defines a lifting axis Z18, which is perpendicular to the mean plane P12. The lifting axis Z18 is thus vertical when the ground S is horizontal. X12 is designated as a longitudinal axis of the frame 12, the longitudinal axis X12 being oriented parallel to the direction of travel of the frame 4. The longitudinal axis X12 is parallel to the horizontal plane P4 and perpendicular to the vertical axis Z8. A transverse axis Y12 of the frame 12 is also defined, which is oriented such that the longitudinal axis X12, the transverse axis Y12, and the lifting axis Z18 together form a right-handed orthogonal coordinate system.

[0035] A displacement "on the ground S" of the scissor lift 10 corresponds to a displacement of the chassis 12 relative to the ground S, this displacement being caused by the rotation of the wheels 14. When the wheels 14 do not rotate, the chassis 12 is considered to be stationary relative to the ground S.

[0036] Some of the wheels 14, for example the wheels 14 of a front axle of the scissor lift 10, are steerable, so as to direct the movement of the scissor lift 10 on the ground S. For example, the wheels 14 of one of the axles 15 are steerable. A steering angle α14 is defined as the angle between the steerable wheels 14 and the longitudinal axis X12. When the wheels 14 are aligned with the longitudinal axis X12, the steering angle α14 is zero. When the steering angle α14 is zero and the wheels 14 are rotating, the chassis 12 moves substantially in a straight line – the ground S being considered flat. When the wheels 14 are steered, in other words, when the steering angle α14 is non-zero, then if the wheels 14 are rotating, the chassis 12 moves substantially along an arc of a circle on the ground.The scissor lift 10 advantageously includes a steering angle measurement device al4, for example an angular sensor mounted on the axle 15 supported by the steerable rollers 14. The angular sensor is not shown.

[0037] When the chassis 12 is stationary relative to the ground S, by extension the scissor lift 10 is also said to be "stationary relative to the ground S", but other movements of the scissor lift 10 generally remain possible, for example it remains possible to raise or lower the basket 16, and / or to change the steering angle al4 of the wheels 14, etc., when these movements are not prohibited for another reason, for example for safety reasons.

[0038] On the four inserts a) to d) of [Fig.2], the scissor gondola 10 is shown in four different configurations, which correspond to four different heights H of the basket 16.

[0039] In insert a), the scissor lift 10 is shown in a lowered configuration, which corresponds to a minimum height Hmin of the basket 16, in which the lifting device 18 is fully retracted. The basket 16 is then in a minimum elevation position, referred to as the lowered position.

[0040] In inset d), the scissor lift 10 is shown in a raised configuration, in which the lifting device 18 is fully extended, while remaining under normal operating conditions. The height H of the basket 16 is equal to a maximum height Hmax. In the raised configuration, the basket 16 is then in its maximum elevation position.

[0041] It is understood that the minimum height Hmin and maximum height Hmax are two extreme values ​​of the height H of the basket 16, which are in particular linked to the design of the parts, in particular to the geometry of the lifting device 18. During normal use of the scissor lift 10, the user sets the height H of the basket 16 between these two extreme heights Hmin and Hmax.

[0042] On insert b) of [Fig.2], the basket 16 is shown in a first intermediate position between the lowered position and the maximum lifting position, the scissor lift 10 being in a first intermediate configuration, in which the height H of the basket 16 is equal to a first height threshold Hl, which is strictly less than the maximum height Hmax.

[0043] In inset c) of [Fig. 2], the scissor lift 10 is shown in a second intermediate configuration, in which the height H of the basket 16 is equal to a second height threshold H2, which is strictly less than the maximum height Hmax and strictly greater than the first height threshold HL

[0044] The scissor lift 10 also includes a first measuring device, which is configured to measure the height H of the basket 16. The first measuring device is not shown. The first measuring device includes, for example, an angle sensor, which measures an angle between two successive bars of the busbar set 20. Alternatively, the first lifting device includes a sensor for the stroke of the actuator 22. The height H, measured by the first measuring device, is a the first quantity which characterizes a state of the scissor gondola 10, in other words the height H is a first characteristic quantity of states of the scissor gondola 10.

[0045] With further reference to inset c) of [Fig. 2], the basket 16 is shown as supporting a load Ml, which has a given mass. The load Ml is said to be carried in the basket 16. The load Ml includes, for example, one or more people present on the platform 17A, and / or tools, materials, etc., transported on the platform 17A.

[0046] The scissor lift 10 includes a measuring device configured to measure the mass of the load Ml carried in the basket 16. The device for measuring the mass Ml carried is not shown. By way of non-limiting example, the device for measuring the mass of the load Ml carried includes load sensors integrated into the joints of the busbar 20, as described in published application FR-3 105 202.

[0047] It is understood that the higher the mass of the load Ml and the higher the height H of the basket 16, then in the event of untimely movement of the scissor lift 10 on the ground S, the risks of tipping of the scissor lift 10 increase.

[0048] In [Fig. 2], the ground S is assumed to be flat, but not horizontal, as it has a slope. It is understood that the lifting axis H18 is not perfectly vertical. In [Fig. 3], the scissor lift 10 is shown on a ground S that is not flat. To compensate for the unevenness of the ground S, one of the axles of the scissor lift 10, here axle 15 shown in [Fig. 3], is "oscillating," meaning that this oscillating axle 15 pivots, relative to the rest of the chassis 12, around an axis parallel to the longitudinal axis X12. The oscillating axle 15 thus serves to compensate, at least partially, for an unevenness of the ground S, so that the lifting axis Z18 is kept substantially vertical.

[0049] An oscillation angle α15 is defined as the angle between an axis A15 of the oscillating axle 15 and the mean plane P12. When the scissor lift 10 moves on a flat surface S, the oscillation angle α15 is zero. The scissor lift 10 includes a measuring device configured to measure the oscillation angle α15, for example, an angle sensor mounted on the chassis 12. The device for measuring the oscillation angle α15 is not shown.

[0050] It is understood that, depending on the situation, the scissor lift 10 is required to operate on a surface S with varying degrees of flatness, hardness, etc. The surface S is said to form a "slab" when it has a leveled and compacted surface. "Leveled" means a substantially flat and horizontal surface. "Compacted surface" means a surface considered rigid during the passage of the scissor lift 10; in particular, no ruts are formed as it passes over it. wheels 14. A slab corresponds for example to the concrete floor S of a logistics warehouse.

[0051] The mass of the load Ml carried in the basket 16, the oscillation angle al5 of the oscillating axle 15 of the scissor lift 10, or the steering angle al4 of the wheels 14, are all examples of characteristic quantities of states of the scissor lift 10, these characteristic quantities being called "second quantities". Each of the second quantities is measured by means of a respective measuring device.

[0052] It is understood that the higher the height H of the basket 16, and the higher one or more of the second quantities are, then the risks of tipping of the scissor lift 10 are greater in the event of uncontrolled movement of the scissor lift 10 relative to the ground 1. A method of controlling the scissor lift 10, described below with reference to [Fig.4], is implemented to reduce this risk.

[0053] With reference to inset a) of [Fig. 4], the control method comprises a first step 101, during which, while the wheels 14 are not rotating, the height H of the basket 16 is measured so as to obtain a first value. In other words, while the chassis 12 is stationary relative to the ground S, the first characteristic dimension of the scissor lift 10 is measured.

[0054] Also during the first step 101, at least one second characteristic quantity of the states of the scissor lift 10 is measured, each second quantity being different from the first quantity and being measured by means of a respective measuring device, so as to obtain at least one second value. In other words, in the illustrated example, at least one of the following quantities is measured: the mass of the load M1 carried on the basket 16, the oscillation angle al5 of the oscillating axle 15, and the steering angle al4 of the wheels, while the chassis 12 is stationary relative to the ground S.

[0055] The scissor lift 10 advantageously includes a computer 17D, which includes a memory - not shown -, so that the computer 17D is configured to record the values ​​of the measurements taken during the first step 101. The computer 17D is for example integrated into the controller 17C.

[0056] The 17D calculator is also configured to store one or more nomograms.

[0057] The first value, together with one or more of the second values, forms one or more groups of values. Each group of values ​​is associated with a respective nomogram and forms the coordinates of a point on that nomogram. In the present case, the first value is a measure of the height H of the basket 16, the second values ​​being measures of the mass of the load Ml, the steering angle al4, or the oscillation angle al5. It is therefore theoretically possible to form three groups of values ​​comprising a single second value, in particular the groups of values ​​{Ml,H], {Ml,al4}, and {Ml,al5}, three groups of values ​​comprising two second values: {Ml,H,al4}, {Ml,H,al5} and {Ml,al4,al5}, and a single group of values ​​comprising three second values: {Ml,H,al4,al5}. However, not all groups of values ​​are necessarily useful.

[0058] According to a preferred embodiment, each group of values ​​comprises, in addition to the first value, a single second value, the nomogram associated with each group of values ​​forming, in graphical representation, a two-dimensional space. A first example of such a nomogram, referenced 110, is graphically represented in inset b) of [Fig. 4]. The nomogram 110 is here associated with the mass of the load Ml and the height H. In other words, the group of values ​​{Ml,H] forms the coordinates of a point in this nomogram 110, which defines, in graphical representation, a two-dimensional space that is easy to represent and visualize. For example, the nomogram 110 and the point corresponding to the associated group of values ​​are displayed on the controller 17C, for the attention of the user present on the basket 16. The graphical representation of the nomogram 110 is not limited.

[0059] The chart 110 is divided into an authorized zone ZI and a prohibited zone Z2, which is complementary to the authorized zone ZI. The authorized zone ZI and the prohibited zone Z2 are separated by a continuous boundary Fl 10. In other words, the boundary Fl 10 is characteristic of the chart 110 and divides the space of the chart 110 into two complementary zones, the authorized zone ZI and the prohibited zone Z2.

[0060] More generally, the control method includes a second step 102, which is subsequent to the first step 101 and during which it is evaluated, by means of the computer 17D and the nomogram 110 recorded in the computer 17D, whether the group of values ​​measured in the first step 101 is included in the authorization zone ZI or in the prohibition zone Z2 of the nomogram 110.

[0061] The control method also includes a third step 103, which is subsequent to the second step 102 and during which the movement of the scissor lift 10 on the ground is authorized or not by means of a controller - here by means of the controller 17C - depending on the evaluation of the second step 102. If, in the second step 102, the value group is located in the authorization zone Zl, then in the third step 103 the movement S of the scissor lift 10 on the ground is authorized. "Authorization to move on the ground" does not mean that the scissor lift 10 will automatically start moving on the ground; it means that if the user commands the movement of the scissor lift 10, for example to the area of ​​the controller 17C, then the user's command is accepted and executed.

[0062] If, in the second step 102, the value group is located in the prohibition zone Z2, then in the third step 103 the ground movement S of the gondola is prohibited scissors 10. In other words, even if the user commands the movement of the scissor lift 10, then the user's command is not executed.

[0063] In the illustrated example, the value group associated with the nomogram 110 includes the height H and the mass of the onboard load Ml. It is understood that when the height H is reduced, for example equal to the minimum height Hmin, the ground movement of the scissor lift 10 must be possible regardless of the onboard load Ml – in compliance with the specifications of the scissor lift 10, of course. Thus, in the graphical representation of the nomogram 110, the authorization zone ZI includes the origin of the nomogram 110.

[0064] Thus, during the third step 103, the controller 17C only authorizes the movement of the scissor lift S on the ground if the load Ml is sufficiently reduced relative to the height H, and conversely, if the height H is sufficiently reduced relative to the load Ml. The control method according to the invention thus makes it possible to move the scissor lift 10 without risk of tipping, meaning that the safety of people and equipment is maintained, and this without having to return the basket 16 to the lowered position, which saves time and energy.

[0065] As illustrated in [Fig. 4] b), the permitted zone Z1 and the prohibited zone Z2 are advantageously divided according to predetermined thresholds of the first and second values ​​considered, in order to facilitate understanding of the nomogram 110, particularly when the user is in a complex environment, for example when the user is located on the basket 10 and the scissor lift 10 is operating on a construction site, the environment of which is not well controlled. The boundary Fl 10 here has a stepped shape.

[0066] Each second quantity, Ml,al4oual5, evolves between a minimum value L0 and a nominal value Lmax, which are defined by design of the scissor lift 10. For each second quantity, a first threshold Ll is also defined, which is a predetermined threshold strictly lower than the nominal value Lmax, and strictly higher than the minimum value L0, as well as a second threshold L2, which is strictly lower than the first threshold Ll and strictly higher than the minimum value L0.

[0067] When, in the first step 101, the first value H is less than the first height threshold Hl, then, in the second step 102, as long as the second value is less than a nominal value Lmax associated with this second characteristic quantity, then the group of associated values ​​is included in the authorization zone ZI of the corresponding nomogram.

[0068] When, in the first step 101, the first value H is between the first height threshold H1 and a second height threshold H2, the second height threshold being intermediate between the first height threshold H1 and the maximum height Hmax from basket 16, then, at the second step 102, as long as the second value is less than the first threshold Ll, then the group of values ​​is included in the authorization zone Zl.

[0069] When, in the first step 101, the first value H is between the second height threshold H2 and the maximum height Hmax of the basket, then, as long as the second value is less than the second threshold L2, then, in the second step 102, the group of values ​​is included in the authorization zone Zl.

[0070] The example illustrated by means of the nomogram 110, associated with the values ​​of height H and mass of load Ml carried, in other words associated with the group of values ​​{H,Ml], is transposable to the other groups of values, in particular here to the groups of values ​​{Ml,al4} and {Ml,al5}.

[0071] The situation of the abacus 110, defined by two thresholds associated with the first quantity and by two thresholds associated with the second quantity, is nevertheless preferred, because it is easy for the user to understand.

[0072] Preferably, the safety criteria associated with several groups of values ​​are considered simultaneously. Thus, during the first step 101, at least two second values ​​Ml / al4 / al5 are measured, which are respectively associated with different second characteristic quantities.

[0073] The first value H forms, with each of the two second values ​​Ml / al4 / al5, at least two groups of values, each of which is associated with a respective nomogram. The at least two groups of values ​​are therefore chosen here from among the three groups of values ​​{Ml,H], {Ml,al4} and {Ml,al5}. Three nomograms are thus provided.

[0074] According to examples, these three nomograms, not shown, are similar to nomogram 110, in that the characteristic lines separating the permitted zones from the prohibited zones have a stepped shape. In other words, for each nomogram, two thresholds are defined for the first quantity, and two thresholds are defined for each second quantity. Advantageously, the thresholds defined for the first quantity, that is, the thresholds H1 and H2 defined for the height H, are identical for each nomogram, so as to standardize the height criterion between each nomogram and to facilitate understanding by the user.

[0075] During the second step 102, it is assessed whether each group of values ​​is included in the permitted zone Z1 or in the prohibited zone Z2 of the corresponding nomogram. During the third step 103, the ground movement S of the scissor lift 10 is permitted if each group of values ​​is located in the permitted zone Z1 of the corresponding nomogram. In other words, for each of the measured second values, if at least one of the associated groups of values ​​is located in the prohibited zone Z2 of the nomogram corresponding to that group of values, then in the third step, the ground movement S of the scissor lift 10 is prohibited. The safety of the scissor lift 10 is thus improved, as it takes into account multiple criteria, each associated with states of the scissor lift 10.

[0076] Alternative embodiments of the invention are illustrated in Figures 5 to 7. In the alternative embodiments of the invention, the elements analogous to those of the other embodiments bear the same reference numerals and function in the same way. The following primarily describes the differences between each embodiment and the preceding one(s).

[0077] An alternative lifting platform, here a scissor lift 11, is shown in [Fig. 5]. The scissor lift 11 differs from the scissor lift 10 described previously in that the platform 17A is extendable, i.e., the basket 16 includes an extension 19, which can be deployed or retracted, depending on the user's needs. The platform 17A is generally aligned, along the lifting axis Z18, with the lifting device 18.

[0078] On insert a) of [Fig. 5], the extension 19 is shown in a so-called stowed position, the basket 16 being in a stowed configuration. A first load M' is shown, placed on the platform 17A.

[0079] On insert b), the extension 19 is in the deployed position, meaning that the extension 19 extends beyond the platform 17A and prolongs the platform 17A, thus increasing the loading area of ​​the basket 16. The basket 16 is then in a so-called deployed configuration. A second load M” and a third load M”' are shown, the second load M” being placed on the platform 17A, while the third load M”' is placed on the extension 19. In the illustrated example, the combined mass of the second load M” and the third load M”' is considered to be equal to the mass of the first load M’. Thus the second load M” is globally aligned, along the lifting axis Z18, with the lifting device 18, while the third load M'” is not aligned with the lifting device 18. It is understood that the heavier the third load M'” is, the less stable the scissor lift 11 is.

[0080] C19 is called a mass distribution coefficient for the load carried in basket 16. In a non-limiting example, the coefficient C19 is equal to the ratio of the mass of the third load M'', located on the extension 19, to the total mass of the loads located on basket 16, which in this case is the sum of the second load M'' and the third load M'''. For example, if the mass of the third load M''' is equal to the mass of the second load M''', then the coefficient C19 is equal to 1 / (1+1) = 1 / 2, or 0.5. If the mass of the third load M''' is four times greater than the mass of the second load M''', then the coefficient C19 is equal to 1 / (4+1) = 1 / 5, or 0.2. Other equivalent definitions of the coefficient C19 are of course possible. The coefficient C19 thus characterizes the distribution, between platform 17A and extension 19, of the total mass carried in basket 16.

[0081] The scissor lift 11 includes a measuring device configured to measure the coefficient C19. Advantageously, the measuring device configured to measure the coefficient C19 is the same as the measuring device used to measure the mass of the total load carried in the basket 16. The coefficient C19 is another example of a second characteristic quantity of states of the scissor lift 11.

[0082] The control method described above is implemented using the coefficient C19; that is, in the first step 101, the coefficient C19 is used to form, together with the first quantity and possibly with one or more other second quantities, a group of values. The second step 102 and the third step 103 are implemented as described above.

[0083] Two alternative abacuses, referenced 111 and 120, are shown in [Fig.6], respectively in insets a) and b).

[0084] In inset a), the nomogram 111 is characterized by a boundary Fl 11. The nomogram 110, described previously with reference to [Fig. 4] b), is defined by two thresholds of the first quantity and by two thresholds of the second quantity, namely the first threshold of height H1, the second threshold of height H2, the first threshold L1, and the second threshold L2. Naturally, the number of thresholds associated with the first quantity or with each second quantity can be adjusted as needed. It is understood that as the number of thresholds increases, the size of the steps in the characteristic curve decreases, until the boundary Fl 11 becomes a smooth curve, as shown in inset a) of [Fig. 6].

[0085] In the example illustrated in [Fig. 6] b), the nomogram 120 is a three-dimensional nomogram, that is, associated with a value group comprising the first quantity and two second quantities, here the mass of the onboard load M1 and the steering angle al4. The three-dimensional space of the nomogram 120 is divided in two by a boundary F120 so as to separate the permitted zone Z1 from the prohibited zone Z2. The boundary F120 is here a continuous surface.

[0086] It is understood that when the steering angle al4 is zero, whether the group of values ​​is located in the permitted zone ZI or in the prohibited zone Z2 depends only on the first quantity H and the second non-zero quantity, here the load ML. We thus find ourselves in the conditions of the nomogram 111, illustrated in [Fig.6] a). In other words, on the nomogram 120 of [Fig.6] b), the intersection between the boundary F120 and the plane formed by the two axes H and Ml corresponds to the boundary Fl 11 of the nomogram 111 of [Fig.6] a).

[0087] More generally, it is understood that whatever the number of values ​​forming a group of values, this group of values ​​forms the coordinates of a point in a space of identical dimension. It is therefore possible to define a nomogram associated with this group of values, the nomogram being defined in a space whose dimension is equal to the number of grades of the group of values.

[0088] That said, since the graphical representation of such a space is impossible beyond three, rather than having a single nomogram with more than three dimensions, it is preferable to have several two-dimensional nomograms, their graphical representation - particularly on a screen of the 17C controller - being easy and intuitively understandable.

[0089] Another aspect of the invention is described with reference to [Fig. 7]. A nomogram 130, called the "conditional nomogram," is shown in [Fig. 7]. The conditional nomogram 130 includes a first version 130A and a second version 130B, one or the other of the first version 130A or the second version 130B being activated depending on the environment of the scissor lift 10 or 11.

[0090] For example, the first version 130A is activated when the scissor lift is located on a slab-like floor S, for example in a warehouse, while the second version 130B is activated when the scissor lift is located on a non-slab-like floor S, for example on an outdoor construction site. More generally, when the scissor lift 10 is located on a floor other than a slab-like floor, the scissor lift is said to be in "all-terrain" mode. Preferably, when the scissor lift 10 is required to operate on a non-slab-like floor S, the scissor lift 10 includes an oscillating axle.

[0091] During the second step 102 of the control process, the computer 17D evaluates whether the group of values ​​associated with the conditional nomogram 130 is included in the authorization zone ZI or in the prohibition zone Z2 of the activated version - 130A or 130B - of the conditional nomogram 130.

[0092] Thus, if the scissor lift 10 is located on a slab, then in the second step 102 of the control process, the computer 17D evaluates whether the group of values ​​associated with the conditional nomogram 130 is included in the authorization zone ZI or in the prohibition zone Z2 of the first version 130A of the conditional nomogram 130. If the scissor lift 10 is located elsewhere than on a slab, then in the second step 102 of the control process, the computer 17D evaluates whether the group of values ​​associated with the conditional nomogram 130 is included in the authorization zone ZI or in the prohibition zone Z2 of the second version 130B of the conditional nomogram 130.

[0093] In the example of [Fig.7] a), the first version 130A of the conditional nomogram 130 defines a boundary F130A, which separates the authorization zones ZI and prohibition zones Z2 associated with the first version 130A of the conditional nomogram 130.

[0094] In the example of [Fig.7] b), the second version 130B of the conditional nomogram 130 defines a boundary F130B, which separates the authorization zones ZI and prohibition zones Z2 associated with the second version 130B of the conditional nomogram 130. For comparison, the F130A boundary of the first version 130A is also shown, in dotted lines, on the second version 130B of the nomogram 130.

[0095] It is understood that when the scissor lift 10 is located on a slab, the risks of the scissor lift 10 tipping over are lower than when the scissor lift 10 is located anywhere other than on a slab. In the illustrated example, this is reflected in the fact that the authorization zone ZI of the second version 130B is smaller than the authorization zone ZI of the first version 130A. In other words, the movement authorization criteria are stricter when the scissor lift 10 is in all-terrain mode compared to the situation where the scissor lift 10 is located on a slab.

[0096] Advantageously, in the authorization zone ZI of the second version 130B of the conditional nomogram 130, each point is uniquely associated with a maximum speed instruction for the scissor lift 10 relative to the ground S. Uniquely, it is understood that each point is associated with only one speed instruction. The speed instructions are, for example, stored in a table of numbers, which is previously stored in the computer 17D.

[0097] In the example in [Fig. 7] b), a point PI is materialized in the authorization zone ZI of the second version 130B of the conditional nomogram 130. This point therefore corresponds to a group of measured values ​​characterizing states of the scissor lift 10, here the values ​​associated with the quantities {H, Ml}. The point PI is thus associated with a speed setpoint. According to non-limiting examples, the speed setpoint is given as an absolute value, for example expressed in km / h, or as a relative value, for example as a percentage of a maximum speed of the scissor lift 10.

[0098] During the third step 103 of the control process, the movement authorization given by the controller includes the maximum movement speed setting. In other words, if the user requests, by means of the controller 17C, the movement of the scissor lift 10, and if the controller 17C authorizes the movement of the scissor lift on the ground, then the movement speed is limited by the maximum speed setting given by the controller 17C.

[0099] Advantageously, the maximum travel speed setpoint depends on the measured value of the first quantity H.

[0100] In the example described above, either the first version 130A or the second version 130B of the nomogram 130 is activated depending on whether the 10 / 11 scissor lift is operating in "all-terrain" mode or not. According to yet another variant, either the first version 130A or the second version 130B of the nomogram 130 is activated depending on whether the 10 / 11 scissor lift is operating inside or outside a building, as the risk of wind is higher outside the building than inside. According to a variant not shown, one or the other between the first version 130A or the second version 130B of the 130 abacus is activated according to a number of people present on the platform 17A.

[0101] According to an unillustrated variant, either the first version 130A or the second version 130B of the nomogram 130 is activated depending on a configuration of the scissor lift 10 / 11, for example depending on whether the scissor lift is equipped with an oscillating axle 15, or whether the scissor lift is equipped with an extension 19 of the platform 17A.

[0102] The embodiments and variants mentioned above can be combined with each other to generate new embodiments of the invention.

Claims

1. Demands Method for controlling a lifting platform (10; 11), wherein: • the lifting platform (10; 11) includes wheels (14) and is configured to move on the ground (S) by rotating the wheels (14), the direction of movement of the lifting platform (10; 11) on the ground (S) being controlled by means of steering the wheels (14), the lifting platform optionally including an oscillating axle (15) and / or a basket (16) with an extension (19), • during a first step (101), while the wheels (14) are not turning: • a first quantity characteristic of the states of the lifting platform (10; 11) is measured by means of a first measuring device, the first quantity being a height (H) of the basket (16) of the lifting platform (10; 11) relative to a lowered position of the basket (16), so as to obtain a first value, and • at least one second characteristic quantity (Ml, al4, al5, C19) of states of the lifting platform (10; 11) is measured, each second quantity being different from the first quantity and being measured by means of a measuring device, so as to obtain at least one second value, • at least one second characteristic quantity is chosen from: • a mass of a load (Ml) carried in the basket (16), • an oscillation angle (al5) of an oscillating axle (15) of the lifting platform (10; 11), • a coefficient (C19) for the distribution of the mass of the load (Ml) carried in an extension (19) of the basket (16), or a steering angle (a 14) of the wheels (14), the first value forming, with at least one second value measured for each second quantity, a group of values, • in a second step (102), subsequent to the first step (101), the following is evaluated: • by means of a calculator (17D) and a nomogram (110; 111; 120; 130) stored in the calculator (17D), each group of values ​​being associated with a respective nomogram and forming coordinates of a point in that nomogram, the nomogram being divided into an authorization zone (Z1) and a prohibition zone (Z2), which is complementary to the authorization zone (Z1), • if the group of values ​​measured in the first step (101) is included in the permitted zone (Z1) or in the prohibited zone (Z2) of the nomogram (110; 111; 120; 130), • during a third step (103), subsequent to the second step (102), the movement on the ground (S) of the lifting platform (10; 11) is authorized or not by means of a controller (17C) according to the evaluation of the second step (102).

2. A control method according to claim 1, wherein: • in the first step (101), at least two second values ​​are measured, which are respectively associated with different second characteristic quantities (Ml, al4, al5, C19), • the first value forms, with each of the two second values, two groups of values, which are each associated with a respective nomogram (110; 111; 120; 130), • in the second step (102), it is evaluated whether each group of values ​​is included in the authorization zone (Zl) or in the prohibition zone (Z2) of the corresponding nomogram, • in the third step (103), the ground movement (S) of the lifting platform is authorized if each group of values ​​is located in the authorization zone (Zl) of the corresponding nomogram.

3. A control method according to any one of claims 1 or 2, wherein: • one of the nomograms used during the second step (102) is a conditional nomogram (130), which includes a first version (130A) and a second version (130B), either of the first version (130A) or the second version (130B) being activated depending on the environment and / or a configuration of the lifting platform (10; 11).

4. A control method according to claim 3, wherein: • The first version (130A) is activated when the lifting platform (10; 11) is located on a floor (S) forming a slab, the slab having a leveled and compacted surface, while the second version (130B) is activated when the lifting platform is located on a floor not forming a slab; • During the second step (102), the computer (17D) evaluates whether the group of values ​​associated with the conditional nomogram (130) is included in the permission zone (Z1) or in the prohibition zone (Z2) of the activated version of the conditional nomogram.

5. A control method according to any one of claims 3 or 4, wherein: • in the authorization zone (Zl) of the second version (130B) of the conditional nomogram (130), each point (PI) is uniquely associated with a maximum ground travel speed setpoint (S) of the lifting platform (10; 11), • during the third step (103), the travel authorization includes the maximum travel speed setpoint.

6. Control method according to claim 5, wherein: • the maximum travel speed setpoint depends on the measured value of the first quantity (H).

7. A control method according to any one of claims 1 to 6, wherein: • each group of values ​​comprises, in addition to the first value (H), a single second value (M1, a14, a15, C19), the nomogram (110; 111; 130) associated with each group of values ​​forming, in graphical representation, a two-dimensional space.

8. A control method according to claim 7, wherein, for each value group: when, in the first step (101), the first value (H) is less than a first height threshold (Hl), the first height threshold being strictly less than a maximum height (Hmax) of the basket (16), then, in the second step (102), as long as the second value (Ml, al4, al5, C19) is less than a nominal value (Lmax) associated with this second characteristic quantity, then the group of values ​​is included in the authorization zone (Zl) of the associated nomogram (110; 111; 130), when, in the first step (101), the first value is between the first height threshold (Hl) and a second height threshold (H2), the second height threshold being intermediate between the first height threshold (Hl) and the maximum height (Hmax) of the basket (16), then, in the second step (102), as long as the second value is less than a predetermined first threshold (Ll),the first predetermined threshold being strictly less than the nominal value (Lmax) associated with this second characteristic quantity, then the group of values ​​is included in the authorization zone (Zl), when, at the first step (101), the first value is between the second height threshold (H2) and the maximum height (Hmax) of the basket (16), then, as long as the second value is less than a second predetermined threshold (L2), the second predetermined threshold being strictly less than the first predetermined threshold (Ll), then, at the second step (102), the group of values ​​is included in the authorization zone (Zl).

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