ES3034537T3 - Method for maintenance of a crane - Google Patents

Abstract

A method for maintaining a crane (1), said crane comprising a control-command system connected to a piloting device (2) designed to allow piloting of a plurality of maneuvers, said maintenance method being characterized in that it implements: - a configuration change step by means of a maintenance control system for switching said crane into a maintenance configuration, where the piloting of a maneuver is initially blocked by the control-command system, - a selection step for selecting, by means of a maintenance module (5) in connection with the control-command system, a maintenance maneuver from among the maneuvers whose piloting is initially blocked, - an unlocking step in which the control-command system unlocks the piloting of said maintenance maneuver, and - a step of piloting said maintenance maneuver by means of the piloting device. (Automatic translation with Google Translate, without legal value)

Description

DESCRIPTION

Crane maintenance procedure

The present invention relates to a crane maintenance method.

It also refers to a crane and a maintenance kit suitable for the implementation of said maintenance procedure.

In the crane sector, for example, tower cranes with a mast supporting a boom and suitable for moving loads, it is often necessary to perform maintenance operations on active cranes, already assembled and installed at an operating site.

For example, such maintenance operations may be carried out to repair and rehabilitate a crane in the event of technical problems that prevent it from functioning, or to prevent deterioration of the crane, which could lead to a degradation in its performance.

To carry out such maintenance operations on a crane, a maintenance technician, for example trained by the manufacturer of said crane, must go to the place of operation of said crane, accompanied by a crane operator: while the crane operator controls, from a control cabin generally located at the top of the crane mast, certain manoeuvres of the crane, at the request of the maintenance technician, the latter can observe the operation of the crane, identify any technical problems encountered and carry out the necessary repairs.

During these maintenance operations, the maintenance technician is thus exposed to the movements of the moving parts of the crane (e.g., boom movements, etc.): there is therefore a risk that the maintenance technician may be struck by a moving part of the crane during a maneuver controlled by the crane operator.

Several devices are already known from the state of the art that can improve the safety of the maintenance technician during a maintenance operation.

For example, document CN201753235 describes a crane that can be configured, by means of a switch, between a working configuration, in which the crane can operate normally, and a maintenance configuration, in which no movement of the crane is permitted: by transitioning the crane to the maintenance configuration before the maintenance technician intervenes on the crane, the safety of the latter is guaranteed. Document CN201753235 describes a method according to the preamble of claim 1.

However, it is impossible for the maintenance technician to observe the operation of the crane and identify the repairs that need to be performed while the crane is in the maintenance configuration: switching the crane to the maintenance configuration makes maintenance operations inconvenient and tedious. Document CN207566749 describes a device capable of detecting the presence of the maintenance technician in a danger zone and then automatically blocking or limiting crane movements that could cause it to hit the maintenance technician. This device has the disadvantage that, in the event of an error in detecting the maintenance technician, the latter's safety is no longer guaranteed, and the maintenance technician may be hit by the crane.

In addition, on each of the two devices mentioned above, the maintenance technician must transmit instructions to the crane operator positioned in the control cabin for controlling each specific maneuver he wishes to observe: this transmission of instructions is generally carried out by voice or through appropriate communication means.

There is a risk that the crane operator may not understand the instructions given by the maintenance technician or may make a mistake during the execution of the instructions and perform a false maneuver. In this case, the technician is exposed to a sudden crane maneuver that he could not have anticipated and is therefore in danger.

The state of the art can also be illustrated by the explanations of document US2010/116767, which relates to a method for controlling a crane, either by a crane operator using a fixed control unit, or by a remote person using a mobile remote control unit, allowing the remote person to take control of the crane's maneuvers. However, such a solution is not suitable for maintenance operations, since the crane maneuvers are controlled by either the crane operator or the remote person, without the possibility of allowing the remote person to act on the crane operator's control; the remote person is content to take full control over the control.

The objective of the present invention is therefore to resolve all or part of the aforementioned drawbacks by proposing a crane maintenance method that ensures greater safety for the maintenance technician when carrying out maintenance operations.

Another objective of the invention is to propose a maintenance method that limits the risk of the crane operator performing an incorrect maneuver. Yet another objective of the invention is to propose a maintenance method that allows the maintenance technician to automatically limit the maneuvers that the crane operator can perform, in order to better anticipate the different movements of the crane and limit the risk of collision.

Finally, an objective of the invention is to propose a maintenance procedure that can be easily implemented in existing conventional crane models.

To this end, it proposes a maintenance procedure for a crane, configurable between a working configuration and a maintenance configuration, said crane including a control-command system connected to a control device intended to allow, when said crane is in the working configuration, the control of a plurality of maneuvers, each of which implements at least one movement of at least one mobile part of said crane,

said maintenance procedure being characterized by performing at least the following stages:

- a step of changing the configuration of the crane by means of a maintenance control system, to make said crane go into the maintenance configuration, in which the control, by means of the control device, of at least one maneuver among the plurality of maneuvers is initially blocked by the control-command system,

- a selection stage, to select, by means of a maintenance module together with the control-command system, at least one maintenance manoeuvre, from among the manoeuvres whose control is initially blocked,

- an unlocking step, in which the control-command system unlocks the control of said maintenance maneuver to release the control of said maintenance maneuver by means of the control device, and,

- a stage of controlling said maintenance maneuver by means of the control device.

Carrying out such a maintenance method according to the invention therefore requires collaboration between two operators present at the crane's operating site: a crane operator, who controls the various crane maneuvers by means of the control device, and a maintenance technician, who makes it possible to put the crane into a maintenance configuration, by means of the maintenance control system, and to observe the maneuvers controlled by the crane operator.

It should be noted that the control device, which is operated by a crane operator, may be a control device located in a control cabin mounted on the crane, or it may be a radio-controlled control device external to the crane.

The maintenance procedure establishes a hierarchy between the maintenance technician and the crane operator: the maintenance technician chooses which crane maneuvers he wants to be carried out, while the crane operator only plays the role of executor, and cannot control any crane maneuvers except those selected by the maintenance technician.

In a first embodiment, the maintenance control system is an automated maintenance control system for performing the configuration change step in an automated manner.

In a second embodiment, the maintenance control system is a switch for manually performing the configuration change step, such as, for example, a physical switch or a virtual switch in a display interface.

In a first embodiment, the switch is positioned on the crane and outside a control cabin in which the control device is arranged, so that it cannot be actuated by the crane operator present in the control cabin.

According to one possibility, the crane includes a mast designed to extend, when said crane is in operation, in a substantially vertical direction between a foot positioned near the ground and a top portion above it, which supports a boom, the switch being located on the foot and the control cabin being located on the mast above the switch.

Thus, the control cabin is positioned at the top of the crane mast, and the switch is positioned close to the ground, for example, in an electrical cabinet of said crane, easily accessible to the maintenance technician. In a second embodiment, the switch is positioned on the crane, and inside a control cabin in which the control device is arranged, and the switch is accessible by means of a secure access, such as a key, a password, or an identification device; this secure access therefore allows only the maintenance technician, and not the crane operator, to access the switch.

Obviously, other embodiments are possible relating to the relative arrangement of the switch and the control cabin, but it is especially advantageous for the maintenance technician (and not the crane operator) to manipulate the switch so that he is the one who chooses to start the maintenance procedure by putting the crane into the maintenance configuration.

In addition, various types of switches are possible, for example, a key switch, a switch, an RFID reader, a keypad for entering a password, etc.

The maintenance method according to the invention therefore includes a succession of steps that allow the maintenance technician to impose on the crane operator control of certain specific maneuvers, to the exclusion of all others.

The first step, carried out or initiated by the maintenance technician either manually or automatically, therefore consists of moving the crane from the working configuration, in which the crane operator can control any crane maneuver using the control device, to the maintenance configuration, in which control of at least one of these maneuvers is blocked.

In other words, once the crane is in the maintenance configuration, the crane operator can no longer perform, using the control device, some of the maneuvers that he or she could control when the crane was still in the working configuration.

The maintenance technician therefore knows that the crane operator can only perform a limited number of predefined maneuvers that he can easily anticipate: even in the event of a control error by the crane operator, the maintenance technician cannot be surprised by an unexpected maneuver, thus reducing the risk of collision with a moving part of the crane.

In a preferred embodiment of the invention, at the end of the configuration change stage, the control, by means of the control device, of each of the maneuvers among the plurality of maneuvers, is blocked by the control-command system.

Therefore, when the crane enters maintenance mode, the crane operator cannot initially perform any maneuvers using the control device: the maintenance technician's safety is therefore maximized.

The crane's maneuver control is blocked by the crane's control system after the crane enters the maintenance configuration, for example, after the switch has been manipulated by a maintenance technician.

This control-command system is present in numerous models of latest-generation cranes and can, for example, consist of one or more electronic cards, and is adapted to carry out the movements of the moving parts of the crane implemented during maneuvers controlled from the crane control device.

This control-command system can also be suitable for controlling, specifically by means of physical sensors distributed throughout the crane, these movements of the moving parts of the crane.

In the context of the maintenance method according to the invention, the control-command system is also configured to block the control, by means of the control device, of certain maneuvers of the crane, so that, even when the crane operator manipulates the control device to perform these same maneuvers, the crane does not effectively perform these maneuvers.

In other words, if the crane operator controls a maneuver whose control is blocked by the control-command system, the movements of one or more moving parts implemented by said maneuver are not carried out.

At the end of the crane configuration change phase, the control-command system thus prevents certain crane maneuvers from being performed, even if the crane operator mistakenly controls these maneuvers using the control device.

According to one feature, the transition of the crane from the working configuration to the maintenance configuration is indicated by the emission of a warning signal, such as, for example, an acoustic signal and/or a light signal.

It is also possible that this acoustic and/or light signal may be emitted repeatedly while the crane is in the maintenance configuration.

Of course, it is possible, within the context of the invention, for no such warning signal to be issued during the transition of the crane from the working configuration to the maintenance configuration. The maintenance method therefore includes a selection step, during which at least one maintenance maneuver is selected from among the one or more maneuvers whose control is initially blocked. In a first embodiment, this selection step is automated, for example, following a predefined or recorded maintenance scenario, said maintenance scenario being able to be configured in advance in the maintenance module.

In this first embodiment, the maintenance module comprises a memory in which one or more maintenance scenarios are stored.

In a second embodiment, this selection step is carried out manually by the maintenance technician who selects, by means of the maintenance module, at least one maintenance maneuver from among the crane maneuvers whose control is blocked by the control-command system.

Therefore, the maintenance technician chooses a specific maneuver to observe how the crane is performing, for example, to identify the cause of a technical problem or to verify proper operation after a repair. The maintenance module, which will be described in more detail below, is connected to the crane's control system.

In the second embodiment, the maintenance module advantageously includes an interface that allows the maintenance technician to select the maintenance maneuver.

Of course, the invention is not limited to the manner in which the selection of the maintenance maneuver is carried out, whether in an automated or pre-established manner, or manually, or by means of selection software launched by the maintenance technician, or any other equivalent means for carrying out said selection.

It should be noted that the maintenance maneuver, selected from among all the maneuvers the crane can perform, can also be performed without prior selection when the crane is in working configuration. Once the maintenance technician has selected the maintenance maneuver he wishes to perform, or to have it performed automatically in a maintenance scenario, the maintenance module transmits a control signal to the crane's control system during the unlocking phase, requiring the control device to unlock this maintenance maneuver.

Once control of the maintenance maneuver has been unlocked by the control-command system, the crane operator can perform the maneuver using the control device. It is important to note that control of the other previously blocked maneuvers remains blocked: the crane operator can only perform maintenance control. The maintenance module can also be used to start and stop the crane.

Therefore, the maintenance method according to the invention allows the maintenance technician to precisely select the one or more specific maneuvers he wishes to see performed by the crane operator, prohibiting the latter from controlling any other unauthorized maneuvers.

The maintenance method according to the invention therefore has many advantages:

- makes it possible to avoid any error in the crane operator's control that could endanger the safety of the maintenance technician,

- allows the maintenance technician to request the crane operator, through the control-command system, to control certain specific maneuvers, avoiding any communication problems between them, and

- Its implementation is simple, since the crane's maneuvers remain controlled by the crane operator: the implementation of the maintenance method according to the invention does not require, in particular, any device for the maintenance technician to take remote control of the crane, which would be much more complex and costly.

In one embodiment, the maintenance maneuver involves at least one maintenance movement of at least one mobile part of said crane, said maintenance movement being characterized, when the crane is in the working configuration, by at least one kinematic parameter having a maximum working threshold,

said maintenance procedure including a limitation stage, to limit the kinematics of said maintenance movement when the maintenance maneuver is controlled during the control stage, so that the kinematic parameter of said maintenance movement has a maximum maintenance threshold that is less than or equal to said maximum working threshold, said limitation stage previously including a selection sub-stage consisting of selecting said maximum maintenance threshold in the maintenance module.

In this embodiment, the maintenance technician can, in addition to precisely selecting a maintenance maneuver to be performed, choose to limit the kinematics of this maintenance maneuver in order to more accurately study the operation of the crane.

It should be noted that this sub-selection stage can also be carried out automatically in the context of a pre-established maintenance scenario.

It should also be noted that this limitation step, although advantageous, is optional, and therefore, in the maintenance configuration, there is no mandatory action on the kinematic limitations of one or more maintenance movements.

The maintenance procedure includes a limitation stage which, in turn, includes a selection sub-stage: during this selection sub-stage, the maintenance technician can select a maximum maintenance threshold which will constitute an upper limit that cannot be exceeded, for the kinematic parameter after controlling the maintenance maneuver during the control stage.

More precisely, each crane maneuver that can be carried out in the working configuration is characterized by one or more kinematic parameters, each of which is associated with a maximum working threshold: this maximum working threshold presents a value below which the kinematic parameter values must remain, to ensure the correct operation of the crane and avoid damaging it.

For example, the kinematic parameter may correspond to a speed parameter of one of the moving parts of the crane set in motion by the crane's maneuvers, and the maximum working threshold then corresponds to a maximum speed that said moving part must not exceed when the crane is used in a working configuration.

The selection sub-stage therefore consists in associating (for example, via the maintenance module) with each maintenance manoeuvre selected during the selection stage a maximum maintenance threshold less than or equal to the maximum working threshold: this maximum maintenance threshold has a value below which the kinematic parameter values must remain when the maintenance manoeuvre is carried out during the control stage.

For example, when the kinematic parameter corresponds to a speed parameter of one of the moving parts of the crane set in motion by the maintenance maneuver, the maximum maintenance threshold corresponds to a maximum speed that said moving part must not exceed when the crane is used in a maintenance configuration.

The selection sub-stage therefore allows the maintenance technician to choose the maximum maintenance threshold value below which the kinematic parameter values must remain during the control stage.

Alternatively, this maximum maintenance threshold value can also be selected or configured in advance in the context of a pre-defined maintenance scenario.

Once the value of this maximum maintenance threshold has been selected in the maintenance module, it transmits a control signal to the crane's control-command system, which forces the control of the maintenance maneuver to be limited.

It is important to note that, at the end of this limitation stage, the kinematic parameter cannot exceed the maximum maintenance threshold, regardless of the control commands sent by the crane operator via the control device.

The limitation stage therefore allows the maintenance technician to "restrict" the operation of the crane and impose high limits on the kinematics of the maintenance maneuver, in order to be able to study the maintenance maneuver in a less rapid and less dangerous manner than if this maintenance maneuver were carried out under normal working conditions, when the crane is in working configuration.

According to one possibility, the kinematic parameter corresponds to a holding travel speed, the maximum working threshold corresponds to a maximum working speed and the maximum holding threshold corresponds to a maximum holding speed,

consequently, said maintenance movement, during the control stage, presents a speed less than or equal to said maximum maintenance speed, said maximum maintenance speed being less than or equal to said maximum working speed.

In one variant, the kinematic parameter corresponds to a holding displacement amplitude, the maximum working threshold corresponds to a maximum working amplitude and the maximum holding threshold corresponds to a maximum holding amplitude,

consequently, said maintenance displacement, during the control stage, presents an amplitude less than or equal to said maximum maintenance amplitude, said maximum maintenance amplitude being less than or equal to said maximum working amplitude.

In another variant, the kinematic parameter corresponds to a holding displacement acceleration, the maximum working threshold corresponds to a maximum working acceleration and the maximum holding threshold corresponds to a maximum holding acceleration,

said maintenance displacement therefore presenting, during the control stage, an acceleration less than or equal to said maximum maintenance acceleration, said maximum maintenance acceleration being less than or equal to said maximum working acceleration.

The maintenance technician can thus limit the amplitude, speed, or even acceleration of the selected maintenance maneuver, in order to observe, for example, smaller and less rapid movements of the moving parts implemented by the maneuver.

According to one possibility, during the selection sub-stage of the limitation stage, the maximum maintenance threshold is selected from at least two distinct thresholds, including a lower threshold and an upper threshold.

According to another possibility, during the selection sub-stage of the limitation stage, the maximum maintenance threshold is selected only between the lower threshold and the upper threshold.

Therefore, the invention contemplates that the maintenance technician chooses the maximum maintenance threshold from a finite list of possible pre-parameterized thresholds, each being less than or equal to the maximum working threshold.

Specifically, this list may include:

- an upper threshold, the value of which is equal to that of the maximum working threshold, and

- a lower threshold, the value of which is strictly lower, or even much lower, than that of the maximum working threshold.

Therefore, the maintenance technician may choose, for example, during the selection sub-stage, to operate the crane in a "slow mode," in which the kinematics of the maintenance maneuver have a speed limited below a lower speed threshold that is much lower than the maximum working threshold.

Conversely, you can also choose, during the selection sub-stage, to operate the crane in a "fast mode", in which the kinematics of the maintenance maneuver have a speed limited below a high-speed threshold equal to the maximum working threshold: the crane operator can therefore control the maintenance maneuver in the same way as if the crane were in the working configuration.

Advantageously, the maintenance procedure comprises a calibration step consisting of setting an upper threshold value and/or a lower threshold value.

This calibration step can therefore allow the maintenance technician to assign a value of their choice to the lower and upper thresholds, before choosing one or the other during the selection sub-step. For example, the calibration step may precede the selection sub-step and the limitation step may follow the selection step: the maintenance technician therefore begins by setting the value of the lower and upper thresholds before the selection step; they then select the maintenance maneuver during the selection step; they then choose one or the other of the lower and upper thresholds during the selection sub-step, in order to limit the kinematics of the maintenance maneuver.

It should be noted that each of these maintenance technician actions is carried out using the maintenance module.

Of course, other embodiments are possible, for example, embodiments in which the maintenance technician has the possibility to directly assign a value to the maximum maintenance threshold (by means of a keypad or other input device) during the selection sub-stage.

Numerous embodiments are also possible with regard to the maintenance module, which, in particular, may have different types of configurations and be located in various positions relative to the crane. In a preferred embodiment of the invention, the maintenance module is a portable device and is not attached to the crane, said maintenance module being wirelessly connected to the crane's control system.

This allows the maintenance technician to carry the maintenance module with him when moving around the crane, allowing him to perform the selection, limitation, and/or calibration steps right where he is, without having to continually return to a fixed position where the maintenance module would be located.

On the other hand, this implementation has a major operational advantage: a maintenance technician can perform maintenance operations on several different cranes using a single maintenance module compatible with each of them (i.e. suitable for linking to the control-command system of each of the cranes in question), for example, in the context of an after-sales service provided by the manufacturer of said cranes to their respective operators.

In another embodiment, the maintenance module is a device integrated into the crane, for example, located near the switch at the foot of the crane.

It is also possible for the maintenance module to be a device external to the crane and can be connected directly to the crane at a specific location.

The maintenance module can also be an external device to the crane that can be connected via a cable connection to the crane's control-command system.

The maintenance module may also have a suitable interface to allow the maintenance technician, in particular, to easily and quickly select the maintenance maneuver during the selection stage, to select the maximum maintenance threshold during the selection sub-stage of the limitation stage.

Numerous possibilities can be considered, the maintenance module interface being able to present a selection device comprising, for example, touch screens, keyboards or even functional keys or buttons (or a combination of these elements), said selection device being able to be associated with one or more display screens.

According to one characteristic, the selection sub-stage is carried out by means of a selection device of the maintenance module, said selection device having at least a first selection unit and a second selection unit designed to be manipulated by an operator, said first selection unit and said second selection unit being separated from each other by a distance whose measurement is greater than 20 or 30 centimeters, such that said first selection unit and second selection unit cannot be manipulated simultaneously with one hand by the same operator.

This feature is optional, but it is nevertheless advantageous, since it allows to improve the safety of the maintenance technician when he chooses the upper threshold value as the maximum maintenance threshold, i.e. when he decides to allow the control of the maintenance maneuver by the crane operator in conditions close to those of the working configuration (the upper threshold having a value equal to that of the maximum working threshold): in fact, the crane operator can then, for example, control the maintenance maneuver at high speed, which could endanger the maintenance technician.

Therefore, it is envisaged that the first selection unit and the second selection unit are arranged so that the maintenance technician cannot accidentally or inadvertently operate both of them at the same time with one hand: if the maintenance technician wishes to select the upper threshold, it is necessary for him to use both hands to make this selection by means of the maintenance module, thus reducing the probability of errors.

For example, the first selection unit and the second selection unit may consist of push buttons whose combined manipulation allows the maintenance technician to carry out the selection steps and the selection sub-step of the limiting stage.

Below you can find an example of an embodiment of the maintenance module selection device and its operation by the maintenance technician.

In one embodiment, the crane control-command system is suitable for implementing, during the control stage, at least one maintenance control cycle including the following stages:

- a stage of measuring a value of the kinematic parameter,

- a step of comparing said value with a maintenance limit threshold, the value of which corresponds to that of the maximum maintenance threshold increased by a predefined maintenance tolerance margin, and

- an immediate stop stage of the crane operation if the value of the kinematic parameter is greater than said maintenance limit threshold.

Therefore, the crane control-command system is suitable for monitoring the kinematics of the maintenance maneuver carried out during the control stage, in order to ensure that the speed limit imposed by the maintenance technician on the crane operator during the limitation stage is effectively respected.

To this end, the control-command system includes at least one physical sensor capable of measuring the speed of a moving part of the crane set in motion during the maintenance maneuver. This measurement can be direct, for example, by means of one or more tachometers, or indirect.

The control-command system then compares this speed measurement with the maintenance limit threshold, obtained by adding the maximum maintenance threshold and a predefined maintenance tolerance margin: this maintenance tolerance margin allows the uncertainties of the speed measurement to be taken into account, and can be freely set.

If the speed measurement value exceeds this maintenance limit threshold, the control-command system activates an emergency stop of the crane, interrupting any maneuvers during control.

In fact, since the speed limit imposed by the maintenance technician is not effectively respected, it is necessary to stop the crane from operating to ensure its safety.

According to one possibility, the crane control-command system is suitable for implementing, during a performance of the maintenance maneuver when the crane is in the working configuration, at least one work control cycle that includes the following steps:

- a stage of measuring a value of the kinematic parameter,

- a stage of comparing said value with a working limit threshold, the value of which corresponds to that of the maximum working threshold plus a predefined working tolerance margin, and

- an immediate stoppage of the crane operation if the value of the kinematic parameter is greater than said maintenance limit threshold,

said working tolerance margin being strictly greater than the maintenance tolerance margin.

Therefore, the crane control-command system is also suitable for monitoring the kinematics of the maintenance maneuver when the crane is in the working configuration, in order to ensure that the speed of a moving part of the crane set in motion during the performance of the maintenance maneuver does not exceed the maximum working threshold, in order to avoid any damage to the crane.

As during the maintenance control cycle, the control-command system is suitable for comparing the speed measurement made by means of one or more physical sensors of the control-command system with the working limit threshold, obtained by adding the maximum working threshold and a predefined working tolerance margin that allows taking into account the uncertainties of the speed measurement, and which can be freely set.

It is worth noting that the maintenance tolerance margin is chosen to be smaller than the working tolerance margin: the kinematics of the maintenance maneuver are therefore monitored with a stricter tolerance when the crane is in the maintenance configuration than when the crane is in the working configuration, in order to ensure the safety of the maintenance technician.

Advantageously, the maintenance module sends acknowledgment signals to the control-command system,

said control-command system being suitable for measuring the time elapsed since the reception of a last acknowledgment signal sent by the maintenance module,

said control-command system being configured to activate an immediate stop stage of the crane operation when said elapsed time is greater than a previously defined time limit.

This feature ensures the safety of the maintenance technician in the event of a communication interruption between the maintenance module and the crane control system.

In fact, the maintenance module and the control-command system exchange, for example, at regular intervals, acknowledgment signals, to confirm the correct reception of the information and orders transmitted between them: if the crane control-command system does not receive any acknowledgment signals for a time interval exceeding a pre-set time limit (sometimes called "time-out"), it means that communication with the maintenance module is interrupted and that the maintenance technician's instructions entered via the maintenance module cannot be taken into account or implemented by the crane control-command system.

The control-command system therefore triggers an emergency stop of the crane if this time limit is exceeded.

For example, the time limit is set to 100 milliseconds.

In one embodiment, the crane control-command system is suitable for detecting, for each maneuver, at least one characteristic movement of said maneuver,

said maintenance control system being configured to activate an immediate stoppage of the crane operation if it detects at least one movement characteristic of a maneuver that has not been previously selected during the selection stage.

The crane control-command system is therefore capable of identifying each possible crane maneuver by means of at least one characteristic movement, and includes at least one motion sensor that allows detecting said movements characteristic of said maneuvers.

If the control-command system detects a movement characteristic of one of the maneuvers whose control has been blocked during the crane configuration change stage but has not been unlocked during the unlocking stage (i.e. the maneuver has not been selected by the maintenance technician during the selection stage), it means that the control-command system does not perfectly achieve blocking of the control of the crane maneuvers, and that the maintenance method according to the invention is not correctly implemented.

The control-command system then activates, in this case, an emergency stop of the crane, to ensure the safety of the maintenance technician.

The invention also relates to a crane, configurable between a working configuration and a maintenance configuration, said crane including a control-command system connected to a control device intended to allow, when said crane is in the working configuration, the control of a plurality of maneuvers, each of which implements at least one movement of at least one mobile part of said crane,

in which the control-command system is suitable for blocking control, by means of the control device, of at least one maneuver among the plurality of maneuvers,

said crane including a maintenance control system connected to the control-command system and suitable for causing said crane to enter the maintenance configuration, in which control, by means of the control device, of at least one maneuver among the plurality of maneuvers is blocked by the control-command system,

and in which the control-command system is designed to be connected to a maintenance module and is suitable for unlocking, when the crane is in maintenance configuration and based on orders issued by said maintenance module, the control of at least one maneuver among the plurality of maneuvers whose control is blocked by the control-command system, said control being carried out by means of the control device.

In a first embodiment, the maintenance control system is an automated maintenance control system.

In a second embodiment, the maintenance control system is a switch, as described above, such as, for example, a physical switch or a virtual switch in a display interface. It also relates to a maintenance assembly including a crane as described above and a maintenance module intended to be connected to the control-command system of said crane, said maintenance module being suitable for:

- allow an operator to select at least one maintenance manoeuvre from among the one or more manoeuvres whose control is blocked by said control-command system,

- sending an unlocking signal to said control-command system to order the unlocking of the control of said maintenance maneuver, said control being carried out by means of the control device. In one embodiment, the maintenance module is a portable device and is not attached to the crane, said maintenance module being wirelessly connected to the crane's control-command system.

Other features and advantages of the present invention will become evident upon reading the following detailed description of a non-limiting implementation example, made with reference to the attached figures, in which:

[Figure 1] is a schematic view of a maintenance assembly according to the invention, consisting of a crane and a maintenance module;

[Figure 2] is a schematic representation of a maintenance method according to the invention, implemented by means of the maintenance assembly according to the invention.

Figure 1 represents a crane 1 according to the invention, including a mast M extending substantially in a vertical direction V (perpendicularly to a ground S on which the mast M is arranged) and supporting a boom F which is substantially horizontal and articulated in rotation with respect to the mast M.

Therefore, the mast M has a foot P, located near the ground S, and a top SO, near its joint with the boom F.

The crane 1 also includes a control cabin C, fixed to the upper part SO of the mast M and inside which a control device 2 is arranged.

This control device 2 is intended to be manipulated by a crane operator present in the control cabin C, in order to perform various crane maneuvers. In a variant not shown, the control device is a radio-controlled control device for remote control by the crane operator.

For example, the crane operator can, by means of the control device 2, control a horizontal turning movement of the boom F relative to the mast M, or a movement of a pulley MO of the crane along said boom F, or even a vertical lifting movement of a load (not shown) connected to said pulley MO.

This control device 2 is connected to a control-command system 4 (not shown in Figure 1) of the crane, said control-command system 4 being specifically suitable for controlling the actuators (also not shown) of said crane, in order to carry out the maneuvers controlled by the crane operator by means of the control device 2.

For example, in order to carry out a turning movement of the boom F, the control-command system 4 may be suitable for controlling, according to the orders transmitted by the control device 2, a motor arranged in the upper part of the mast M, to exert on the boom F a mechanical torque capable of making it rotate.

The crane 1 also includes a switch 3 fixed on the foot P of the mast M and connected to the control system 4, said switch 3 being suitable for making the crane 1 pass between:

- a working configuration, in which all maneuvers of the crane 1 can be controlled by means of the control device 2, and

- a maintenance configuration, in which the control of at least one of these manoeuvres is blocked by the control-command system 4 (i.e. in which at least one manoeuvre of the crane 1 can no longer be controlled by means of the control device 2).

The working configuration is the configuration in which the crane 1 is located most of the time when it is in operation, while the maintenance configuration is especially suitable for implementing a maintenance method 100 according to the invention, said maintenance method 100 making it possible to carry out maintenance operations on the crane 1.

A more precise description of the maintenance procedure 100 can be found below.

In the embodiment shown in Figure 1, the switch 3 consists of a key system comprising a lock 31 cooperating with a key 32: by turning the key 32 of the lock 31 in opposite directions, the maintenance technician can alternatively make the crane 1 pass from the working configuration to the maintenance configuration, and vice versa.

Obviously, many other realizations are possible.

Switch 3 is positioned close to the ground S and is intended to be manipulated by a maintenance technician T (not shown in Figure 1): due to the relative position of the control cabin C (high above the mast M) and switch 3 (close to the ground S), the same operator cannot therefore simultaneously control the manoeuvres of crane 1 by means of control device 2 and activate switch 3.

In fact, carrying out the maintenance operations made possible by manipulating the switch 3 requires the presence of at least two operators on the crane 1: a maintenance technician T, positioned outside the control cabin C, who studies the movements of the crane 1 and carries out possible repairs, and a crane operator, positioned in the control cabin C, who performs certain crane manoeuvres at the request of the maintenance technician T, as will be described later.

Furthermore, the maintenance technician is equipped with a portable maintenance module 5 which is not fixed to the crane 1.

This maintenance module 5 is in wireless connection with the control-command system 4 of the crane 1, and allows the maintenance technician T to impose control of certain maneuvers on the crane operator during the maintenance procedure 100 according to the invention.

It should be noted that the wireless communication between the maintenance module 5 and the crane 1 is reciprocal, with the maintenance module 5 being able to send and receive information from the control-command system 4 of the crane 1, and vice versa.

The maintenance module 5 and the crane 1 thus form a maintenance assembly 101 suitable for the implementation of the maintenance procedure 100.

Figure 2 details the different steps of a maintenance procedure 100 according to the invention, suitable for carrying out maintenance operations on the crane 1 through collaboration between the maintenance technician T and the crane operator.

As mentioned above, the maintenance procedure 100 includes a configuration change step 6 that allows the crane 1 to be moved from the working configuration to the maintenance configuration.

This configuration change stage 6 includes several successive sub-stages:

- a sub-stage 61, in which the maintenance technician T manipulates the switch 3,

- a sub-stage 62, in which the switch 3 sends to the control-command system 4 an order to go to the maintenance configuration, and

- a sub-stage 63, in which the control-command system 4 blocks the control of all possible maneuvers of the crane 1.

Therefore, at the end of the configuration change step 6, the crane operator cannot control any maneuvers of the crane 1 by means of the control device 2.

In other words, manipulation of the control device 2 by the crane operator cannot result in the performance of any crane maneuvers as long as the control of these maneuvers remains blocked by the control-command system 4.

In the preferred embodiment of the maintenance procedure 100, the control-command system 4 prevents control of all the crane maneuvers: other embodiments are possible, in which the crane operator can still control certain predefined maneuvers at the end of the sub-step 63.

The maintenance procedure 100 therefore includes a calibration step 7, formed by a single sub-step 71, during which the maintenance technician has the possibility of assigning, by means of the maintenance module 5, values of his choice, to two parameters, an upper threshold and a lower threshold, whose function will be explained below.

The values of these two parameters are stored in memory by the maintenance module 5 and are such that the value of the lower threshold is less than that of the upper threshold.

The maintenance procedure 100 therefore includes a selection step 8, formed by a single sub-step 81, during which the maintenance technician T selects, by means of the maintenance module 5, a maintenance maneuver from among the crane maneuvers whose control is blocked by the control-command system 4: this maintenance maneuver is a crane maneuver that the maintenance technician T wishes to see performed by the crane operator by means of the control device 2, for example, to verify the effectiveness of certain repairs.

Sub-step 81 may be carried out in numerous different ways, depending on the type of maintenance module 5.

In the embodiment shown in Figure 1, the maintenance module 5 includes a first pressure button B1 and a second pressure button B2, as well as indicator lights 51, each of these indicator lights 51 corresponding to a specific maneuver of the crane 1.

To select the maintenance maneuver, the maintenance technician T keeps the first pressure button B1 pressed and presses the second pressure button B2 repeatedly: each press on this second pressure button B2 allows a new maneuver to be selected, and the indicator light 51 associated with the latter lights up to inform the maintenance technician T of the selected maneuver.

Many other embodiments remain possible, for example embodiments in which the maintenance module 5 includes a touch screen on which the maintenance technician T can directly select a maintenance maneuver.

Once the maintenance maneuver has been selected, the maintenance module 5 transmits to the control-command system 4 an instruction to unlock said maintenance maneuver during a sub-step 91; the control-command system 4 then effectively unlocks control of this maintenance maneuver by the control device 2.

Sub-step 91 and sub-step 92 together form an unlocking step 9 of the maintenance procedure 100.

Therefore, at the end of sub-step 92, the crane operator is able to control the maintenance maneuver by means of control device 2.

However, control of all other maneuvers of crane 1 remains blocked by control-command system 4.

The maintenance procedure 100 therefore includes a limitation step 10, which allows the maintenance technician T to limit the kinematics of the maintenance maneuver controlled by the crane operator and, in particular, to limit the speed of the one or more moving parts set in motion during this maintenance maneuver.

More precisely, this limitation step 10 includes a selection sub-step 101, during which the maintenance technician T chooses one or the other of the upper threshold and the lower threshold whose values were parameterized during the sub-step 71.

This upper threshold and this lower threshold constitute two possible values of a maximum maintenance threshold that defines a speed limit that one or more moving parts set in motion during the maintenance maneuver must not exceed.

In other words, the maximum maintenance threshold represents the speed below which the maintenance technician T wishes to see the maintenance maneuver performed.

Therefore, if maintenance technician T wants the crane operator to perform the maintenance maneuver at a lower speed, for example, to be able to observe the operation of crane 1 in detail or to limit the damage it suffers in the event of a malfunction, he will choose the lower threshold during sub-step 101.

If, on the other hand, you want the crane operator to perform the maintenance maneuver at a higher speed, closer to the normal operating conditions of crane 1, you will choose the higher threshold during sub-stage 101.

In a preferred embodiment, the upper threshold is equal to a maximum working threshold, which defines a speed limit that the one or more moving parts set in motion during the maintenance maneuver must not exceed when the crane 1 is in working configuration: the choice of the upper threshold by the maintenance technician T therefore again allows the crane operator to control the maintenance maneuver under the same conditions as if the crane were in working configuration.

To make the selection between the lower threshold and the upper threshold, the maintenance module 5 has (as seen in Figure 1) a third pressure button B3: the maintenance technician can indicate his choice of the lower threshold by holding down the second pressure button B2, and his choice of the upper threshold by simultaneously holding down the second pressure button B2 and the third pressure button B3.

As before, numerous embodiments related to the implementation of this sub-step 101 are possible.

It will be noted that the second push button B2 and the third push button B3 are positioned on the maintenance module 5 in such a way that it is impossible for the maintenance technician T to keep them pressed simultaneously with one hand: the second push button B2 and the third push button B3 are, in fact, separated from each other by a separation distance 52 greater than 20 or 30 centimeters, which exceeds the length of the maintenance technician T's hands.

Therefore, to select the upper threshold, the maintenance technician T must use both hands: this feature reduces the risk of the maintenance technician T selecting this upper threshold by mistake or inadvertently, since carrying out the maintenance manoeuvre at high speed is likely to endanger his safety.

It will also be noted that the first push button B1, the second push button B2 and the third push button B3 do not protrude from the maintenance module 5 and are aligned with the surface of the latter: in this way, the risk of the maintenance technician T inadvertently manipulating one of these push buttons B1, B2, B3 is minimized.

Once the maintenance technician T has chosen one of the upper and lower thresholds, the maintenance module 5 transmits a limitation instruction to the control-command system 4 during a sub-step 102; the control-command system 4 then effectively limits the kinematics of the maintenance maneuver during a sub-step 103, so that the one or more movements implemented by the latter cannot exceed the chosen upper or lower threshold.

Therefore, limitation stage 10 allows maintenance technician T to “restrict” the operation of crane 1 and require the crane operator to control the maintenance maneuver at a lower speed.

Once the limitation stage 10 is completed, the crane operator can control the maintenance maneuver selected by the maintenance technician (during sub-stage 81), at the speed also selected by the maintenance technician (during sub-stage 101).

The crane operator thus manipulates the control device 2 and this control device then transmits the control instructions to the control-command system 4, during a sub-step 111, so that it effectively carries out the maintenance maneuver requested by the maintenance technician T.

The succession of configuration change steps 6, selection 8, unlocking 9 and then limitation 10 therefore allows the maintenance technician T to work in complete safety on the crane 1, ensuring that the crane operator can only control the single maintenance manoeuvre that he himself selected in the maintenance module 5, and at the maximum speed that he has also chosen: in this way, any danger linked to an error by the crane operator or to poor communication between the crane operator and the maintenance technician T is avoided.

It should be noted that these steps of the maintenance procedure 100 can be repeated several times in succession, to allow consecutively several different maintenance maneuvers and, therefore, to perform several maintenance operations on the crane 1.

Claims (16)

1. Maintenance procedure (100) of a crane (1), configurable between a working configuration and a maintenance configuration, said crane (1) including a control-command system (4) connected to a control device (2) intended to allow, when said crane (1) is in the working configuration, a control of a plurality of maneuvers, each of which implements at least one movement of at least one mobile part of said crane (1), said maintenance procedure (100) being characterized in that it carries out at least the following steps: - a step of changing the configuration (6) of the crane (1) by means of a maintenance control system, to make said crane (1) pass into the maintenance configuration, in which the control, by means of the control device (2), of at least one maneuver among the plurality of maneuvers is initially blocked by the control-command system (4), - a selection stage (8), for selecting, by means of a maintenance module (5) together with the control-command system (4), at least one maintenance manoeuvre, from among the manoeuvres whose control is initially blocked, - an unlocking step (9), in which the control-command system (4) unlocks the control of said maintenance maneuver in order to release the control of said maintenance maneuver by means of the control device (2), and, - a stage of controlling (11) said maintenance maneuver by means of the control device (2). 2. Maintenance procedure (100), according to the preceding claim, wherein, at the end of the configuration change stage, the control, by means of the control device (2), of each of the maneuvers among the plurality of maneuvers is blocked by the control-command system (4). 3. Maintenance method (100) according to any one of the preceding claims, wherein the maintenance maneuver carries out at least one maintenance movement of at least one mobile part of said crane (1), said maintenance movement being characterized in that, when the crane (1) is in the working configuration, by at least one kinematic parameter that has a maximum working threshold, said maintenance procedure (100) including a limitation stage (10) to limit the kinematics of said maintenance movement when the maintenance maneuver is controlled during the control stage, so that the kinematic parameter of said maintenance movement has a maximum maintenance threshold less than or equal to said maximum working threshold, said limitation stage (10) previously including a selection sub-stage (101) consisting of selecting said maximum maintenance threshold in the maintenance module (5). 4. Maintenance method (100) according to claim 3, wherein the kinematic parameter corresponds to a speed of the maintenance movement, the maximum working threshold corresponds to a maximum working speed and the maximum maintenance threshold corresponds to a maximum maintenance speed, consequently, said maintenance movement, during the control stage, presents a speed less than or equal to said maximum maintenance speed, said maximum maintenance speed being less than or equal to said maximum working speed. 5. Maintenance method (100) according to any one of claims 1 to 4, wherein the maintenance control system is an automated maintenance control system for performing the configuration change step (6) in an automated manner. 6. Maintenance method (100) according to any one of claims 1 to 4, wherein the maintenance control system is a switch (3) for manually performing the configuration change step (6), such as, for example, a physical switch or a virtual switch in a display interface. 7. Maintenance method (100) according to claim 6, wherein the switch (3) is positioned on the crane (1), outside a control cabin (C) in which the control device (2) is arranged. 8. Maintenance method (100), according to any one of the preceding claims, wherein the maintenance module (5) is a portable device and is not fixed to the crane (1), said maintenance module (5) being in wireless connection with the control-command system (4) of the crane (1). 9. Maintenance procedure (100) according to claim 3, wherein the control-command system (4) of the crane (1) is suitable for implementing, during the control stage, at least one maintenance control cycle including the following stages: - a stage of measuring a value of the kinematic parameter, - a stage of comparing said value with a maintenance limit threshold, the value of which corresponds to that of the maximum maintenance threshold plus a predefined maintenance tolerance margin, and - an immediate stoppage stage of the crane operation (1) if the value of the kinematic parameter is greater than said maintenance limit threshold. 10. Maintenance method (100) according to any one of the preceding claims, wherein the maintenance module (5) sends acknowledgment signals to the control-command system (4), said control-command system (4) being adapted to measure the time elapsed since the reception of a last acknowledgment signal sent by the maintenance module (5), said control-command system (4) being configured to activate a stage of immediate stopping of the operation of the crane (1) when said elapsed time is greater than a previously defined time limit. 11. Maintenance method (100) according to any one of the preceding claims, wherein the control-command system (4) of the crane (1) is suitable for detecting, for each manoeuvre, at least one characteristic movement of said manoeuvre, said control-command system (4) being configured to activate an immediate stoppage of the operation of the crane (1) if it detects at least one movement characteristic of a maneuver that has not been previously selected during the selection stage (8). 12. Crane (1), suitable for a maintenance procedure (100), according to any one of the preceding claims, wherein said crane (1) is configurable between a working configuration and a maintenance configuration, said crane (1) including a control-command system (4) connected to a control device (2) intended to allow, when said crane (1) is in the working configuration, a control of a plurality of maneuvers, each of which implements at least one movement of at least one mobile part of said crane (1), in which the control-command system (4) is suitable for blocking the control, by means of the control device (2), of at least one maneuver among the plurality of maneuvers, said crane (1) including a maintenance control system connected to the control-command system (4), and suitable for passing said crane (1) into the maintenance configuration, in which the control, by means of the control device (2), of at least one maneuver among the plurality of maneuvers is initially blocked by the control-command system (4), and in which the control-command system (4) is intended to be connected to a maintenance module (5), and in which, when the crane (1) is in maintenance configuration, the control-command system (4) is suitable, based on orders issued by said maintenance module (5), to unlock the control of at least one maintenance maneuver among the one or several maneuvers whose control is initially blocked by the control-command system (4) in the maintenance configuration, said control of said maintenance maneuver being carried out by means of the control device (2) in the maintenance configuration. 13. Crane (1) according to claim 12, wherein the maintenance control system is an automated maintenance control system or is a switch (3), such as, for example, a physical switch or a virtual switch in a display interface. 14. Crane (1) according to claim 13, wherein the switch (3) is positioned on said crane (1) and outside the control cabin (C). 15. Crane (1) according to claim 14, wherein the crane (1) includes a mast (M) intended to extend, when said crane (1) is in operation, in a substantially vertical direction between a foot (P) positioned near a ground (S) and an upper part (SO) supporting a boom (F), and the switch (3) is located on the foot (P) and the control cabin (C) is located on the mast (M) above the switch (3). 16. Maintenance assembly (101), including a crane (1), according to any of claims 12 to 15, and a maintenance module (5), intended to be connected to the control-command system (4) of said crane (1), said maintenance module (5) being suitable for: - allow an operator to select at least one maintenance manoeuvre from among the one or more manoeuvres whose control is blocked by said control-command system (4), and - send an unlocking signal to said control-command system (4), in order to order an unlocking of the control of said maintenance maneuver, said control being carried out by means of the control device (2).