METHOD FOR CRANE MAINTENANCE

Description

[0001] The present invention relates to a method of maintaining a crane.

[0002] It also relates to a crane and a maintenance assembly suitable for implementing such a maintenance process.

[0003] In the field of cranes, for example tower cranes with a mast supporting a jib and suitable for moving loads, it is often necessary to carry out maintenance operations on working cranes, already assembled and installed on an operating site.

[0004] For example, such maintenance operations may take place for the purpose of repairing and restoring a crane in the event of technical problems preventing the said crane from operating, or for the purpose of preventively preventing deterioration of the same crane leading to a degradation of its operation.

[0005] 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 operating site of said crane, accompanied by a crane operator: while the crane operator controls, from a control cabin generally located high up on the crane mast, certain maneuvers 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.

[0006] During these maintenance operations, the maintenance technician is thus exposed to the movements of the moving parts of the crane (for example, movements of the boom, etc.): there is therefore a risk that the maintenance technician will be struck by a moving part of the crane during a maneuver controlled by the crane operator.

[0007] Several devices for improving the safety of the maintenance technician during a maintenance operation are already known from the state of the art.

[0008] For example, document CN201753235 describes a crane configurable, 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 switching the crane to the maintenance configuration before the maintenance technician intervenes on the crane, the safety of the latter is ensured. Document CN201753235 describes a method in accordance with the preamble of claim 1."

[0009] However, it is impossible for the maintenance technician to observe the operation of the crane and identify the repairs to be carried out while the crane is in the maintenance configuration: switching the crane to the maintenance configuration thus makes maintenance operations inconvenient and tedious. Document CN207566749 describes a device capable of detecting the presence of the maintenance technician in a danger zone, then automatically blocking or limiting the movements of the crane likely to hit the latter. This device has the disadvantage that in the event of an error during the detection of the maintenance technician, the latter's safety is no longer ensured and the maintenance technician may be struck by the crane.

[0010] In addition, in each of the two aforementioned devices, the maintenance technician must transmit to the crane operator positioned in the control cabin instructions for each particular maneuver that he wishes to observe: this transmission of instructions is generally carried out vocally or via suitable means of communication.

[0011] There is a risk that the crane operator will not understand the instructions given by the maintenance technician or that he will make a mistake when carrying them out and carry out a false manoeuvre: in this case, the technician will be exposed to a sudden manoeuvre of the crane that he could not anticipate and is then in danger.

[0012] The state of the art can also be illustrated by the teachings 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 radio control unit, thus allowing the remote person to take control of the crane's maneuvers. However, such a solution is not suitable for maintenance operations, because the control of the crane's maneuvers is carried out either by the crane operator or by the remote person, without the possibility of allowing the remote person to act on the control by the crane operator; the remote person simply takes full control of the control.

[0013] The present invention thus aims to resolve all or part of the aforementioned drawbacks, by proposing a method of maintaining a crane which allows the maintenance technician to be assured of greater safety when carrying out maintenance operations.

[0014] Another objective of the invention is to propose a maintenance method that makes it possible to limit the risks of the crane operator performing a false maneuver. Yet another objective of the invention is to propose a maintenance method that allows the maintenance technician to automatically limit the maneuvers that can be performed by the crane operator, in order to be able to better anticipate the different movements of the crane and limit the risks of collision.

[0015] Finally, an objective of the invention is to propose a maintenance method which can be easily implemented on existing standard crane models.

[0016] To this end, it proposes a method for maintaining a crane, configurable between a working configuration and a maintenance configuration, said crane comprising a control-command system connected to a piloting device designed to allow, when said crane is in the working configuration, piloting of a plurality of maneuvers each implementing at least one movement of at least one mobile part of said crane, said maintenance method being characterized in that it implements at least the following steps: a step of changing the configuration of the crane by means of a maintenance control system, so as to switch said crane to 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 step for selecting, by means of a maintenance module in connection with the control-command system, at least one maintenance maneuver among the maneuver(s) whose control is initially blocked, an unlocking step in which the control-command system unlocks the control of said maintenance maneuver in order to release the control of said maintenance maneuver by means of the control device, and a step of controlling said maintenance maneuver by means of the control device.

[0017] Carrying out such a maintenance method according to the invention thus requires cooperation between two operators present on the crane operation site: a crane operator, controlling the various maneuvers of the crane by means of the control device, and a maintenance technician, enabling the crane to be put into maintenance configuration, by means of the maintenance control system, and observing the maneuvers controlled by the crane operator.

[0018] It should be noted that the control device, on which a crane operator acts, can be a control device located in a control cabin mounted on the crane, or can be a radio-controlled control device external to the crane.

[0019] The maintenance process establishes a hierarchy between the maintenance technician and the crane operator: the maintenance technician chooses which crane maneuvers he wants to see carried out, while the crane operator only has an executing role, not being able to control any crane maneuvers except those selected by the maintenance technician.

[0020] In a first embodiment, the maintenance control system is an automated maintenance control system for performing the configuration change step in an automated manner.

[0021] In a second embodiment, the maintenance control system is a switch for performing the configuration change step manually, such as a physical switch or a virtual switch on a screen interface.

[0022] In a first embodiment, the switch is positioned on the crane and outside a control cabin where the control device is located, so that it cannot be operated by the crane operator present in the control cabin.

[0023] According to one possibility, the crane comprises a mast intended to extend, when said crane is in operation, in a substantially vertical direction between a foot positioned close to a ground and a high top supporting a boom, the switch being located on the foot and the control cabin being located on the mast above the switch.

[0024] The control cabin is thus positioned high on the mast of the crane and the switch is positioned close to the ground, for example in an electrical cabinet of said crane, easily accessible by the maintenance technician. In a second embodiment, the switch is positioned on the crane, and inside a control cabin where the control device is arranged, and the switch is accessible via secure access, such as for example a key, a password, an identification device; this secure access thus allows only the maintenance technician, and not the crane operator, to access the switch.

[0025] Other embodiments concerning the relative arrangement of the switch and the control cabin are of course conceivable, but it is particularly advantageous for the switch to be operated by the maintenance technician (and not by the crane operator) so that it is the latter who chooses to start the maintenance process by putting the crane into the maintenance configuration.

[0026] In addition, various types of switches can be considered, for example, a key switch, a switch, an RFID reader, a password entry keypad, etc.

[0027] The maintenance method according to the invention thus comprises a succession of steps allowing the maintenance technician to require the crane operator to control certain specific maneuvers, to the exclusion of all others.

[0028] The first step, carried out or initiated by the maintenance technician manually or automatically, consists of switching the crane from the working configuration, in which the crane operator can control any maneuver of the crane using the control device, to the maintenance configuration, in which the control of at least one of these maneuvers is blocked.

[0029] In other words, once the crane is in maintenance configuration, the crane operator can no longer carry out, using the control device, some of the maneuvers that he could control when the crane was still in working configuration.

[0030] Thus, the maintenance technician knows that the crane operator can only carry out a limited number of predefined maneuvers that he can easily anticipate: even in the event of a piloting 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.

[0031] In a preferred embodiment of the invention, at the end of the configuration change step, 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.

[0032] Thus, when the crane is put into maintenance configuration, the crane operator cannot initially carry out any maneuvers using the control device: the safety of the maintenance technician is then maximized.

[0033] The crane's control system is used to lock the crane's maneuvers after switching to maintenance configuration, for example after the maintenance technician has operated the switch.

[0034] This control-command system is present on many models of state-of-the-art cranes and may, for example, consist of one or more electronic cards and is suitable for carrying out the movements of the moving parts of the crane implemented during maneuvers controlled from the crane control device.

[0035] This control system can also be adapted to control, in particular by means of physical sensors distributed on the crane, these movements of the moving parts of the crane.

[0036] 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 in order to carry out these same maneuvers, these are not actually carried out by the crane.

[0037] In other words, if the crane operator controls a maneuver whose control is blocked by the control system, the movement(s) of the moving part(s) implemented by said maneuver are not carried out.

[0038] At the end of the crane configuration change step, the control system thus prevents certain crane maneuvers from being carried out, even if the crane operator were to mistakenly control them using the control device.

[0039] According to one feature, the transition of the crane from the working configuration to the maintenance configuration is signaled by the emission of a warning signal, such as for example an audible signal and / or a light signal.

[0040] It is also possible that such an audible and / or visual signal may be emitted repeatedly for the entire duration the crane is in the maintenance configuration.

[0041] It is of course conceivable, within the framework of the invention, that no such warning signal is emitted when the crane moves from the working configuration to the maintenance configuration.

[0042] The maintenance method then comprises a selection step, during which at least one maintenance maneuver among the maneuver(s) whose control is initially blocked.

[0043] In a first embodiment, this selection step is automated, for example by following a pre-established or recorded maintenance scenario, such a maintenance scenario being able to be configured in advance in the maintenance module.

[0044] In this first embodiment, the maintenance module comprises a memory in which one or more maintenance scenarios are recorded.

[0045] 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.

[0046] The maintenance technician therefore chooses a particular maneuver that he wishes to observe the crane performing, for example to identify the cause of a technical problem, or to check that the crane is functioning correctly following a repair. The maintenance module, which will be described in more detail below, is connected to the crane's control system.

[0047] In the second embodiment, the maintenance module advantageously comprises an interface allowing the maintenance technician to select the maintenance maneuver.

[0048] 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 via selection software launched by the maintenance technician, or any other equivalent means for carrying out such a selection.

[0049] It should be noted that the maintenance maneuver, chosen from among all the maneuvers that can be carried out by the crane, can also be carried out without prior selection when the crane is in working configuration.

[0050] After the maintenance technician has selected the maintenance maneuver that he wishes to see carried out or that is carried out automatically in a maintenance scenario, the maintenance module transmits to the crane control system during the unlocking step, a control signal forcing the unlocking of the control, by means of the control device, of this maintenance maneuver.

[0051] Once the maintenance maneuver control has been unlocked by the control system, the crane operator can perform it using the control device. It is important to note that the control of other previously blocked maneuvers remains blocked: only the maintenance maneuver control can be performed by the crane operator.

[0052] It is also possible that the maintenance module could also be used to start and stop the crane.

[0053] Thus, the maintenance method according to the invention allows the maintenance technician to precisely select the particular maneuver(s) that he wishes to see carried out by the crane operator, while prohibiting the latter from piloting any other unauthorized maneuver.

[0054] The maintenance method according to the invention therefore has multiple advantages: it makes it possible to avoid any piloting error by the crane operator likely to endanger the safety of the maintenance technician, it allows the maintenance technician to impose on the crane operator, via the control-command system, the piloting of certain particular maneuvers while avoiding any communication problem between them, and it is simple to apply, the maneuvers of the crane remaining piloted by the crane operator: the implementation of the maintenance method according to the invention does not require in particular any device for remote control of the crane by the maintenance technician, which would present a much higher complexity and cost.

[0055] In one embodiment, the maintenance maneuver implements 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,

[0056] said maintenance method comprising a limitation step for limiting the kinematics of said maintenance movement when the maintenance maneuver is piloted during the piloting step, so that the kinematic parameter of said maintenance movement has a maximum maintenance threshold less than or equal to said maximum work threshold, said limitation step first comprising a selection sub-step consisting of selecting said maximum maintenance threshold on the maintenance module.

[0057] In this embodiment, the maintenance technician can, in addition to precisely selecting a maintenance maneuver to be carried out, choose to limit the kinematics of this maintenance maneuver in order to be able to study the operation of the crane more precisely.

[0058] It should be noted that this sub-selection step can also be carried out automatically within the framework of a pre-established maintenance scenario.

[0059] It should also be noted that this limitation step, although advantageous, is optional, and that thus, in maintenance configuration, there is not necessarily any action on the kinematic limitations of the maintenance movement(s).

[0060] The maintenance method includes a limitation step which itself includes a selection sub-step: during this selection sub-step, the maintenance technician can select a maximum maintenance threshold which will constitute an upper limit which cannot be exceeded for the kinematic parameter when controlling the maintenance maneuver during the control step.

[0061] 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 has a value below which the values ​​of the kinematic parameter must remain, in order to guarantee proper operation of the crane and avoid damaging it.

[0062] 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 working configuration.

[0063] The selection sub-step then consists of associating (for example by means of the maintenance module) with each maintenance maneuver selected during the selection step a maximum maintenance threshold less than or equal to the maximum work threshold: this maximum maintenance threshold has a value below which the values ​​of the kinematic parameter must remain when the maintenance maneuver is carried out during the piloting step.

[0064] 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 maintenance configuration.

[0065] The selection sub-step therefore allows the maintenance technician to choose the value of the maximum maintenance threshold below which the values ​​of the kinematic parameter must remain during the piloting step.

[0066] Alternatively, this maximum maintenance threshold value can also be chosen or set in advance within the framework of a pre-established maintenance scenario.

[0067] Once the value of this maximum maintenance threshold has been chosen on the maintenance module, it transmits a control signal to the crane's control system forcing the limitation of the maintenance maneuver control.

[0068] It is important to note that, at the end of this limitation step, the kinematic parameter cannot exceed the maximum maintenance threshold, regardless of the control commands sent by the crane operator using the control device.

[0069] The limitation step thus allows the maintenance technician to "restrict" the operation of the crane and to impose high limits on the kinematics of the maintenance maneuver, in order to be able to study the maintenance maneuver less quickly and less dangerously than if this maintenance maneuver were carried out under normal working conditions, when the crane is in working configuration.

[0070] According to one possibility, the kinematic parameter corresponds to a maintenance movement speed, the maximum working threshold corresponds to a maximum working speed and the maximum maintenance threshold corresponds to a maximum maintenance speed,

[0071] said maintenance movement then having, during the piloting step, 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.

[0072] In one variant, the kinematic parameter corresponds to a maintenance displacement amplitude, the maximum working threshold corresponds to a maximum working amplitude and the maximum maintenance threshold corresponds to a maximum maintenance amplitude,

[0073] said maintenance movement then having, during the piloting step, 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.

[0074] In another variant, the kinematic parameter corresponds to an acceleration of the maintenance movement, the maximum working threshold corresponds to a maximum working acceleration and the maximum maintenance threshold corresponds to a maximum maintenance acceleration,

[0075] said maintenance movement then having, during the piloting step, 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.

[0076] The maintenance technician can thus limit the amplitude, speed or acceleration of the maintenance maneuver he has selected, in order to be able to observe, for example, smaller and slower movements of the moving parts used by it.

[0077] According to one possibility, during the selection sub-step of the limitation step, the maximum maintenance threshold is selected from at least two distinct thresholds including a low threshold and a high threshold.

[0078] Alternatively, in the selection sub-step of the limitation step, the maximum maintenance threshold is selected only between the low threshold and the high threshold.

[0079] The invention therefore envisages that the maximum maintenance threshold is chosen by the maintenance technician from a finite list of possible pre-parameterized thresholds, each being less than or equal to the maximum work threshold.

[0080] In particular, it is possible that this list could include: an upper threshold, the value of which is equal to that of the maximum work threshold, and a lower threshold, the value of which is strictly lower, or even significantly lower, than that of the maximum work threshold.

[0081] Thus, the maintenance technician can, for example, choose, during the selection sub-step, to operate the crane in a “slow mode”, in which the kinematics of the maintenance maneuver are limited in speed below a low speed threshold much lower than the maximum working threshold.

[0082] Conversely, he can also choose, during the selection sub-step, to operate the crane in a “fast mode”, in which the kinematics of the maintenance maneuver are limited in speed below a high speed threshold equal to the maximum working threshold: the maintenance maneuver can then be controlled by the crane operator in the same way as if the crane were in the working configuration.

[0083] Advantageously, the maintenance method comprises a calibration step consisting of adjusting a value of the high threshold and / or a value of the low threshold.

[0084] This calibration step can thus allow the maintenance technician to assign a value of his choice to the low threshold and the high threshold, before choosing one or the other during the selection sub-step.

[0085] For example, it is conceivable that the calibration step is prior to the selection sub-step and that the limitation step is subsequent to the selection step: the maintenance technician then begins by adjusting the value of the low threshold and the high threshold before the selection step, then selects the maintenance maneuver during the selection step, then chooses one or the other of the low threshold and the high threshold during the selection sub-step, in order to limit the kinematics of the maintenance maneuver.

[0086] It should be noted that each of these actions of the maintenance technician is carried out using the maintenance module.

[0087] Other embodiments are of course conceivable, for example embodiments in which the maintenance technician has the possibility of directly assigning a value to the maximum maintenance threshold (by means of a keyboard or other input device) during the selection sub-step.

[0088] Numerous embodiments are also possible concerning the maintenance module, which may in particular have different types of nature and be located in various positions relative to the crane.

[0089] In a preferred embodiment of the invention, the maintenance module is a portable device and is not fixed to the crane, said maintenance module being wirelessly connected to the crane's control and command system.

[0090] The maintenance technician can thus take the maintenance module with him when moving around the crane, so that he can carry out the selection, limitation and / or calibration steps right where he is, without having to continually return to a fixed position where the said maintenance module would be located.

[0091] This embodiment also has a major operational advantage: a maintenance technician can carry out maintenance operations on several separate cranes using a single maintenance module compatible with each of them (i.e., being adapted to be linked to the control-command system of each of the cranes concerned), for example as part of an after-sales service provided by the manufacturer of said cranes to their respective operators.

[0092] In another embodiment, the maintenance module is a device integrated into the crane, for example located near the switch on the crane foot.

[0093] It is also possible for the maintenance module to be a device external to the crane and able to be directly connected to it in a dedicated location.

[0094] The maintenance module can also be a device external to the crane which can be connected by wired connection to the control system of said crane.

[0095] The maintenance module may also have an interface adapted to enable the maintenance technician, in particular, to quickly and easily select the maintenance maneuver during the selection step, and to select the maximum maintenance threshold during the selection sub-step of the limitation step.

[0096] Many possibilities are conceivable, the interface of the maintenance module 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.

[0097] According to one characteristic, the selection sub-step is carried out by means of a selection device of the maintenance module, said selection device having at least a first selection member and a second selection member intended to be manipulated by an operator, said first selection member and second selection member being separated from each other by a distance the measurement of which is greater than 20 or 30 centimeters, so that said first selection member and second selection member cannot be simultaneously manipulated with a single hand by the same operator.

[0098] This feature is optional, but it is still advantageous because it improves the safety of the maintenance technician when he chooses the value of the high threshold as the maximum maintenance threshold, i.e. when he chooses to authorize the control of the maintenance maneuver by the crane operator in conditions close to those of the work configuration (the high threshold having a value equal to that of the maximum work threshold): in fact, the crane operator can then, for example, control the maintenance maneuver at high speed, potentially putting the maintenance technician in danger.

[0099] Thus, it is intended that the first selection member and the second selection member are arranged so that the maintenance technician cannot accidentally or inadvertently operate them both at the same time with one hand: if the maintenance technician wishes to select the upper threshold, it is then necessary for him to use both hands to make this selection by means of the maintenance module, thus reducing the probability of errors.

[0100] For example, the first selection member and the second selection member 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 limitation step.

[0101] An example of an embodiment of the maintenance module selection device and its manipulation by the maintenance technician can be found below.

[0102] In one embodiment, the crane control system is adapted to implement, during the piloting step, at least one maintenance control cycle comprising the following steps: a step 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 a step of immediately stopping the operation of the crane if the value of the kinematic parameter is greater than said maintenance limit threshold.

[0103] The crane control system is thus adapted to implement monitoring of the kinematics of the maintenance maneuver carried out during the piloting stage, so as to guarantee that the speed limitation imposed by the maintenance technician on the crane operator during the limitation stage is actually respected.

[0104] For this purpose, the control 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.

[0105] This speed measurement is then compared by the control system to the maintenance limit threshold, obtained by adding the maximum maintenance threshold and a predefined maintenance tolerance margin: this maintenance tolerance margin makes it possible to take into account the uncertainties of the speed measurement and can be freely set.

[0106] If the speed measurement value exceeds this maintenance limit threshold, the control system triggers an emergency stop of the crane, interrupting any maneuver currently being piloted.

[0107] In fact, since the speed limit imposed by the maintenance technician is not actually respected, it is necessary to interrupt the operation of the crane to guarantee its safety.

[0108] According to one possibility, the crane control system is adapted to implement, during a maintenance maneuver when the crane is in the working configuration, at least one work control cycle comprising the following steps: a step of measuring a value of the kinematic parameter, a step of comparing said value with a working limit threshold, the value of which corresponds to that of the maximum working threshold increased by a predefined working tolerance margin, and a step of immediately stopping the operation of the crane if the value of the kinematic parameter is greater than said working limit threshold,

[0109] said working tolerance margin being strictly greater than the maintenance tolerance margin.

[0110] The crane control system is thus also suitable for implementing monitoring of the kinematics of the maintenance manoeuvre when the crane is in working configuration, so as to ensure that the speed of a moving part of the crane set in motion during the performance of the maintenance manoeuvre does not exceed the maximum working threshold, in order to avoid any damage to the crane.

[0111] As during the maintenance control cycle, the control system is adapted to compare the speed measurement carried out by means of the physical sensor(s) of the control system with the working limit threshold, obtained by adding the maximum working threshold and a predefined working tolerance margin allowing the uncertainties of the speed measurement to be taken into account and which can be freely set.

[0112] It should be noted that the maintenance tolerance margin is chosen to be lower than the working tolerance margin: the kinematics of the maintenance maneuver are thus monitored with a stricter tolerance when the crane is in maintenance configuration than when it is in working configuration, in order to guarantee the safety of the maintenance technician.

[0113] Advantageously, the maintenance module sends acknowledgment signals to the control-command system,

[0114] said control-command system being adapted to measure a time elapsed since the reception of a last acknowledgment signal sent by the maintenance module,

[0115] said control-command system being configured to trigger a step of immediate stopping of the operation of the crane when said duration is greater than a previously defined limit duration.

[0116] This feature ensures the safety of the maintenance technician in the event of an interruption in communication between the maintenance module and the crane's control system.

[0117] 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 commands transmitted between them: if the crane control-command system does not receive any acknowledgment signal for a time interval greater than a limit duration (sometimes called "delay" duration), time-out ") previously established, this means that communication with the maintenance module is broken and that the maintenance technician's instructions entered using the maintenance module cannot be taken into account and applied by the crane's control system.

[0118] The control system therefore triggers an emergency stop of the crane if this time limit is exceeded.

[0119] For example, the time limit is set to 100 milliseconds.

[0120] In one embodiment, the crane control system is adapted to detect, for each maneuver, at least one movement characteristic of said maneuver,

[0121] said maintenance control system being configured to trigger an immediate stoppage of the operation of the crane if it detects at least one movement characteristic of a maneuver not previously selected during the selection step.

[0122] The crane control system is thus capable of identifying each possible maneuver of the crane by at least one characteristic movement, and comprises at least one movement sensor making it possible to detect said movements characteristic of said maneuvers.

[0123] If the control system detects a movement characteristic of one of the maneuvers whose control was blocked during the crane configuration change step but was not unlocked during the unlocking step (i.e., the maneuver not having been selected by the maintenance technician during the selection step), this means that the blocking of the control of the crane maneuvers is not perfectly carried out by the control system and that the maintenance method according to the invention is not correctly implemented.

[0124] In this case, the control system triggers an emergency stop of the crane to ensure the safety of the maintenance technician.

[0125] The invention also relates to a crane configurable between a working configuration and a maintenance configuration, said crane comprising a control-command system connected to a piloting device designed to allow, when said crane is in the working configuration, piloting of a plurality of maneuvers each implementing at least one movement of at least one mobile part of said crane, in which the control-command system is adapted to block the piloting, by means of the piloting device, of at least one maneuver among the plurality of maneuvers, said crane comprising a maintenance control system connected to the control-command system and adapted to switch said crane into the maintenance configuration, in which the piloting, by means of the piloting 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 adapted to unlock, when the crane is in the maintenance configuration and according to commands issued by said maintenance module, the piloting of at least one maneuver among the plurality of maneuvers whose piloting is blocked by the control-command system, said piloting being carried out by means of the piloting device.

[0126] In a first embodiment, the maintenance control system is an automated maintenance control system.

[0127] In a second embodiment, the maintenance control system is a switch, already described previously and such as, for example, a physical switch or a virtual switch on a screen interface.

[0128] It also relates to a maintenance assembly comprising a crane as previously described and a maintenance module designed 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 maneuver from among the maneuver(s) whose control is blocked by said control-command system, send an unlocking signal to said control-command system, in order to command an unlocking of the control of said maintenance maneuver, said control being carried out by means of the control device.

[0129] According to one possibility, the maintenance module is a portable device and is not fixed on the crane, said maintenance module being wirelessly linked to the control-command system of the crane.

[0130] Other characteristics and advantages of the present invention will appear on reading the detailed description below of a non-limiting example of implementation, made with reference to the appended figures in which: [ Fig. 1 ] is a schematic view of a maintenance assembly according to the invention, formed of a crane and a maintenance module; [ Fig. 2 ] is a schematic representation of a maintenance method according to the invention, implemented by means of the maintenance assembly according to the invention.

[0131] There figure 1 represents a crane 1 according to the invention, comprising a mast M extending substantially in a vertical direction V (perpendicular to a ground S on which the mast M is arranged) and supporting a jib F which is substantially horizontal and articulated in rotation relative to the mast M.

[0132] The mast M thus has a foot P, located near the ground S, and a top SO, near its articulation with the arrow F.

[0133] Crane 1 also includes a pilot cabin C, fixed to the top SW of mast M and inside which a piloting device 2 is arranged.

[0134] This control device 2 is intended to be operated by a crane operator present in the control cabin C, in order to carry out various maneuvers of the crane. In a variant not illustrated, the control device is a radio-controlled control device for remote control by the crane operator.

[0135] For example, the crane operator can, by means of the control device 2, control a horizontal pivoting movement of the boom F relative to the mast M, or a movement of a block MO of the crane along said boom F, or even a vertical lifting movement of a load (not shown) connected to said block MO.

[0136] This control device 2 is linked to a control-command system 4 (not shown in the figure 1 ) of the crane, said control-command system 4 being particularly adapted to control 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.

[0137] For example, in order to carry out a pivoting movement of the boom F, the control-command system 4 can be adapted to control, according to commands transmitted by the control device 2, a motor arranged at the top of the mast M so as to exert on the boom F a mechanical torque capable of driving it in rotation.

[0138] The crane 1 further comprises a switch 3 fixed to the foot P of the mast M and connected to the control-command system 4, said switch 3 being adapted to switch the crane 1 between: a working configuration, in which all the 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 maneuvers is blocked by the control-command system 4 (that is to say, in which at least one maneuver of the crane 1 can no longer be controlled by means of the control device 2).

[0139] The working configuration is the configuration in which the crane 1 is found most of the time when it is in operation, while the maintenance configuration is particularly 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.

[0140] A more precise description of the maintenance process 100 will be found below.

[0141] In the embodiment represented by the figure 1 , the switch 3 consists of a key system comprising a lock 31 cooperating with a key 32: by turning the key 32 in the lock 31 in opposite directions, the maintenance technician can thus alternately switch the crane 1 from the working configuration to the maintenance configuration, and vice versa.

[0142] Many other embodiments are obviously possible.

[0143] Switch 3 is positioned near the ground S and is intended to be operated by a maintenance technician T (not shown in the figure 1 ): due to the relative positioning of the control cabin C (high on the mast M) and the switch 3 (close to the ground S), the same operator cannot simultaneously control the maneuvers of the crane 1 using the control device 2 and activate the switch 3.

[0144] Indeed, carrying out the maintenance operations made possible by the manipulation of 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, studying the movements of the crane 1 and carrying out any repairs, and a crane operator, positioned in the control cabin C, carrying out certain maneuvers of the crane at the request of the maintenance technician T, as will be described later.

[0145] The maintenance technician is also equipped with a portable maintenance module 5 which is not fixed to the crane 1.

[0146] This maintenance module 5 is wirelessly connected to the control-command system 4 of the crane 1 and allows the maintenance technician T to impose the control of certain maneuvers on the crane operator during the maintenance method 100 according to the invention.

[0147] It will be noted that the wireless communication between the maintenance module 5 and the crane 1 is reciprocal, the maintenance module 5 being able to send and receive information from the control-command system 4 of the crane 1, and vice versa.

[0148] The maintenance module 5 and the crane 1 thus form a maintenance assembly 101 adapted to the implementation of the maintenance method 100.

[0149] There figure 2 details the different stages of a maintenance method 100 according to the invention, adapted to carrying out maintenance operations on the crane 1 through cooperation between the maintenance technician T and the crane operator.

[0150] As previously mentioned, the maintenance method 100 comprises a configuration change step 6 making it possible to change the crane 1 from the working configuration to the maintenance configuration.

[0151] This configuration change step 6 includes several successive sub-steps: a sub-step 61, in which the maintenance technician T manipulates the switch 3, a sub-step 62, in which the switch 3 sends to the control-command system 4 an instruction to switch to maintenance configuration, and a sub-step 63, in which the control-command system 4 blocks the control of all possible maneuvers of the crane 1.

[0152] Thus, at the end of the configuration change step 6, the crane operator cannot control any maneuver of the crane 1 using the control device 2.

[0153] In other words, the manipulation of the control device 2 by the crane operator cannot result in the carrying out of any maneuver of the crane as long as the control of these maneuvers remains blocked by the control-command system 4.

[0154] In the preferred embodiment of the maintenance method 100, the control-command system 4 prevents the control of all the crane maneuvers: other embodiments are possible, in which certain predefined maneuvers remain controllable by the crane operator at the end of sub-step 63.

[0155] The maintenance method 100 then comprises a calibration step 7 formed of 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, a high threshold and a low threshold, the role of which will be explained below.

[0156] The values ​​of these two parameters are kept in memory by the maintenance module 5 and are such that the value of the low threshold is lower than that of the high threshold.

[0157] The maintenance method 100 then comprises a selection step 8 formed of 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 maneuvers of the crane whose control is blocked by the control-command system 4: this maintenance maneuver is a maneuver of the crane that the maintenance technician T wishes to see carried out by the crane operator by means of the control device 2, for example to check the effectiveness of certain repairs.

[0158] Substep 81 can be performed in many different ways, depending on the type of maintenance module 5.

[0159] In the embodiment shown in the figure 1 , the maintenance module 5 comprises a first push button B1 and a second push button B2, as well as indicator lights 51, each of these indicator lights 51 corresponding to a particular maneuver of the crane 1.

[0160] To select the maintenance maneuver, the maintenance technician T keeps the first push button B1 pressed and repeatedly presses the second push button B2: each press on this second push 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.

[0161] Many other embodiments remain conceivable, for example embodiments in which the maintenance module 5 comprises a touch screen on which the maintenance technician T can directly select a maintenance maneuver.

[0162] 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, then the control-command system 4 actually unlocks the control by the control device 2 of this maintenance maneuver.

[0163] Sub-step 91 and sub-step 92 together form an unlocking step 9 of the maintenance method 100.

[0164] Thus, at the end of sub-step 92, the crane operator is able to control the maintenance maneuver using the control device 2.

[0165] However, the control of all other operations of crane 1 remains blocked by control system 4.

[0166] The maintenance method 100 then comprises a limitation step 10, allowing 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 moving part(s) set in motion during this maintenance maneuver.

[0167] This limitation step 10 more precisely comprises a selection sub-step 101, during which the maintenance technician T chooses one or the other of the high threshold and the low threshold, the values ​​of which were set during sub-step 71.

[0168] This upper threshold and this lower threshold constitute two possible values ​​of a maximum maintenance threshold which defines a speed limit that the moving part(s) set in motion during the maintenance maneuver must not exceed.

[0169] In other words, the maximum maintenance threshold represents the speed below which the maintenance technician T wishes to see the maintenance maneuver carried out.

[0170] Thus, if maintenance technician T wants the crane operator to carry out the maintenance maneuver at reduced speed, for example to be able to observe in detail the operation of crane 1 or to limit the damage suffered by it in the event of a malfunction, he will choose the low threshold during sub-step 101.

[0171] If, on the contrary, he wants the crane operator to carry out the maintenance maneuver at a higher speed, closer to the normal operating conditions of crane 1, he will choose the high threshold during sub-step 101.

[0172] In a preferred embodiment, the upper threshold is equal to a maximum working threshold, which defines a speed limit that the moving part(s) set in motion during the maintenance maneuver must not exceed when the crane 1 is in the working configuration: the choice of the upper threshold by the maintenance technician T then amounts to authorizing the crane operator to control the maintenance maneuver under the same conditions as if the crane were in the working configuration.

[0173] In order to select between the low threshold and the high threshold, the maintenance module 5 presents (as visible on the figure 1 ) a third push button B3: the maintenance technician can indicate his choice of the low threshold by holding down the second push button B2, and his choice of the high threshold by holding down the second push button B2 and the third push button B3 simultaneously.

[0174] As previously, numerous embodiments are possible concerning the performance of this sub-step 101.

[0175] 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 using a single hand: the second push button B2 and the third push button B3 are in fact separated from each other by a spacing distance 52 greater than 20 or 30 centimeters, exceeding the span of the hands of the maintenance technician T.

[0176] Thus, to select the high threshold, the maintenance technician T must use both hands: this feature reduces the risk that the maintenance technician T chooses this high threshold by mistake or inadvertently, since carrying out the maintenance maneuver at high speed is likely to put his safety at risk.

[0177] 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 flush with the surface thereof: in this way, the risk of one of these push buttons B1, B2, B3 being inadvertently manipulated by the maintenance technician T is minimized.

[0178] Once one of the high and low thresholds has been chosen by the maintenance technician T, the maintenance module 5 transmits a limitation instruction to the control-command system 4 during a sub-step 102, then the control-command system 4 effectively limits the kinematics of the maintenance maneuver during a sub-step 103, so that the movement(s) implemented by the latter cannot exceed the chosen high or low threshold.

[0179] Limitation step 10 therefore allows maintenance technician T to “restrict” the operation of crane 1 and require the crane operator to control the maintenance maneuver at reduced speed.

[0180] Once limitation step 10 is completed, the crane operator can control the maintenance maneuver selected by the maintenance technician (during sub-step 81), at the speed also selected by the maintenance technician (during sub-step 101).

[0181] The crane operator thus manipulates the control device 2, then this control device transmits to the control-command system 4, during a sub-step 111, control instructions, so that the latter actually carries out the maintenance maneuver requested by the maintenance technician T.

[0182] Thus, the succession of steps of configuration change 6, selection 8, unlocking 9, then limitation 10 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 maneuver that he himself has selected on the maintenance module 5, and at the maximum speed that he has also chosen: any danger linked to a control error by the crane operator or to poor communication between the crane operator and the maintenance technician T is thus avoided.

[0183] It will be noted that these steps of the maintenance method 100 can be repeated several times successively, so as to consecutively authorize several distinct maintenance maneuvers and thus carry out several maintenance operations in turn on the crane 1.

Claims

1. A maintenance method (100) for maintaining a crane (1), configurable between a working configuration and a maintenance configuration, said crane (1) including a monitoring-control system (4) connected to a driving device (2) provided to allow, when said crane (1) is in the working configuration, a driving of a plurality of maneuvers each implementing at least one displacement of at least one movable portion of said crane (1), said maintenance method (100) being characterized in that it implements at least the following steps: - a configuration change step for changing the configuration (6) of the crane (1) by means of a maintenance control system, so as to switch said crane (1) into the maintenance configuration, in which the driving, by means of the driving device (2), of at least one maneuver among the plurality of maneuvers is initially blocked by the monitoring-control system (4), - a selection step (8) for selecting, by means of a maintenance module (5) in connection with the monitoring-control system (4), at least one maintenance maneuver among the maneuver(s) whose driving is initially blocked, - an unblocking step (9) in which the monitoring-control system (4) unblocks the driving of said maintenance maneuver in order to release the driving of said maintenance maneuver by means of the driving device (2), and - a driving step (11)for driving said maintenance maneuver by means of the driving device (2).

2. The maintenance method (100) according to the preceding claim, wherein, at the end of the configuration change step, the driving, by means of the driving device (2), of each of the maneuvers among the plurality of maneuvers is blocked by the monitoring-control system (4).

3. The maintenance method (100) according to any one of the preceding claims, wherein the maintenance maneuver implements at least one maintenance displacement of at least one movable portion of said crane (1), said maintenance displacement being characterized, when the crane (1) is in the working configuration, by at least one kinematic parameter having a maximum working threshold, said maintenance method (100) including a limiting step (10) for limiting the kinematics of said maintenance displacement when the maintenance maneuver is driven during the driving step, such that the kinematic parameter of said maintenance displacement has a maximum maintenance threshold which is less than or equal to said maximum working threshold, said limiting step (10) previously including a selection sub-step (101) consisting in selecting said maximum maintenance threshold on the maintenance module (5).

4. The maintenance method (100) according to claim 3, wherein the kinematic parameter corresponds to a speed of the maintenance displacement, the maximum working threshold corresponds to a maximum working speed and the maximum maintenance threshold corresponds to a maximum maintenance speed, said maintenance displacement then having, during the driving step, a speed which is less than or equal to said maximum maintenance speed, said maximum maintenance speed being less than or equal to said maximum working speed.

5. The maintenance method (100) according to any one of claims 1 to 4, wherein the maintenance control system is an automated maintenance control system to automatically perform the configuration change step (6).

6. The maintenance method (100) according to any one of claims 1 to 4, wherein the maintenance control system is a switch (3) to manually perform the configuration change step (6), such as for example a physical switch or a virtual switch on a screen interface.

7. The maintenance method (100) according to claim 6, wherein the switch (3) is positioned on the crane (1), outside a driving cabin (C) inside which the driving device (2) is located.

8. The maintenance method (100) according to any one of the preceding claims, wherein the maintenance module (5) is a portable device and is not fastened on the crane (1), said maintenance module (5) being in wireless connection with the monitoring-control system (4) of the crane (1).

9. The maintenance method (100) according to claim 3, wherein the monitoring-control system (4) of the crane (1) is adapted to implement, during the driving step, at least one maintenance monitoring cycle including the following steps: - a step of measuring a value of the kinematic parameter, - a step of comparing said value with a maintenance limit threshold, whose value corresponds to that of the maximum maintenance threshold increased by a predefined maintenance tolerance margin, and - a step of immediately stopping the operation of the crane (1) if the value of the kinematic parameter is greater than said maintenance limit threshold.

10. The maintenance method (100) according to any one of the preceding claims, wherein the maintenance module (5) sends acknowledgement signals to the monitoring-control system (4), said monitoring-control system (4) being adapted to measure a duration elapsed since the reception of a last acknowledgment signal sent by the maintenance module (5), said monitoring-control system (4) being configured to trigger a step for immediately stopping the operation of the crane (1) when said duration is greater than a previously defined limit duration.

11. The maintenance method (100) according to any one of the preceding claims, wherein the monitoring-control system (4) of the crane (1) is adapted to detect, for each maneuver, at least one displacement characteristic of said displacement maneuver, said monitoring-control system (4) being configured to trigger an immediate stop of the operation of the crane (1) if it detects at least one displacement characteristic of a maneuver which has not been previously selected during the selection step (8).

12. A crane (1) adapted for a maintenance method (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 monitoring-control system (4) linked to a driving device (2) provided to allow, when said crane (1) is in the working configuration, a driving of a plurality of maneuvers each implementing at least one displacement of at least one movable portion of said crane (1), wherein the monitoring-control system (4) is adapted to block the driving, by means of the driving device (2), of at least one maneuver among the plurality of maneuvers, said crane (1) including a maintenance control system connected to the monitoring-control system (4) and adapted to switch said crane (1) into the maintenance configuration, in which the driving, by means of the driving device (2), of at least one maneuver among the plurality of maneuvers is initially blocked by the monitoring-control system (4), and wherein the monitoring-control system (4) is provided to be connected to a maintenance module (5), and wherein, when the crane (1) is in the maintenance configuration, the monitoring-control system (4) is adapted, depending on commands emitted by said maintenance module (5), to unblock the driving of at least one maintenance maneuver among the maneuver(s) whose driving is initially blocked by the monitoring-control system (4) in the maintenance configuration, said driving of said maintenance maneuver being performed by means of the driving device (2) in the maintenance configuration.

13. The crane (1) according to claim 12, wherein the maintenance control system is an automated maintenance control system or a switch (3), such as for example a physical switch or a virtual switch on a screen interface.

14. The crane (1) according to claim 13, wherein the switch (3) is positioned on said crane (1) and outside the driving cabin (C).

15. The crane (1) according to claim 14, wherein the crane (1) includes a mast (M) provided to extend, when said crane (1) is in operation, in a substantially vertical direction between a foot (P) positioned in the vicinity of a ground (S) and a top (SO) in height supporting a boom (F), and the switch (3) is located on the foot (P) and the driving cabin (C) being located on the mast (M) above the switch (3).

16. A maintenance assembly (101) including a crane (1), in accordance with any one of the claims 12 to 15, and a maintenance module (5) provided to be connected to the monitoring-control system (4) of said crane (1), said maintenance module (5) being adapted to: - allow an operator to select at least one maintenance maneuver among the maneuver(s) whose driving is blocked by said monitoring-control system (4), and - send an unblocking signal to said monitoring-control system (4), in order to control an unblocking of the driving of said maintenance maneuver, said driving being performed by means of the driving device (2).