Control device and method for monitoring such a control device

Abstract

The present invention relates to a control device (10) comprising a lever (11) equipped with a magnetic dipole (14) and movable at least rotationally about a support (12) around an axis (X,Y). Said control device (10) includes a measuring device (21-23) configured to measure a magnetic field (B) generated by said magnetic dipole (14) and a control system (30) for monitoring the integrity of said control device (10). Said control system (30) is configured to signal an anomaly by means of an alarm (35) when a first norm (N1) of a first vector difference between said current magnetic field (Bc) and a first reference magnetic field (Bref1) being relative to an estimated orientation of said lever (11) exceeds a first magnetic field threshold for a duration exceeding a time threshold. Abbreviated figure: Figure 2

Description

Title of the invention: Control device and method for monitoring such a control device

[0001] The present invention lies in the technical field of controls, and is more particularly related to aircraft flight controls.

[0002] The invention relates to a control device and a method for monitoring such a control device.

[0003] A control device includes a handle or lever movable at least about one or more distinct axes, for example, rotation about two orthogonal axes. Translational mobility of the lever about an additional axis, for example, the lever's extension axis, may also be available, generally between a nominal position, also designated as the "neutral" position, and a position called "actuated" or "enabled".

[0004] The control device provides one or more control signals carrying information about the lever's movements relative to its various axes of mobility. The integrity of these control signals is a key safety concern for control devices, particularly in the context of fly-by-wire flight control systems for an aircraft. Indeed, failures affecting a control device can lead to the transmission of erroneous control signals, which will not be detected as such in the absence of safety or monitoring mechanisms. The risk of transmitting erroneous control signals can potentially be increased when the lever is moving in a translational direction along its extension axis.

[0005] A common technology for identifying the movements of a control device's lever is based on the use of magnetic sensors. The movement of the lever modifies a magnetic field detected by a set of sensors. This change in the magnetic field is then converted by a computer into a value representing the lever's displacement.

[0006] This technology is described for example in documents US 7411521 and US 7757579.

[0007] In particular, US patent 7411521 describes a control system comprising a magnet attached to a lever and fixed sensors for detecting lever displacements. At least two sensors, for example Hall effect sensors, are used per axis to detect the movement of the lever relative to a support around that axis. The control system also includes a monitoring arrangement for monitoring a signal provided by each of the sensors and for enabling the control system to be functional when the sensor signals are within a predefined range.

[0008] US patent 7757579 describes a control handle that pivots about two axes on a base. The base has redundant sensors to detect movements of the handle. For example, two Hall effect sensors are used per axis of rotation of the handle and measure variations in a magnetic field generated by a magnet attached to the handle. A microprocessor compares and / or combines the outputs of the two sensors to control the operation of the handle.

[0009] An alternative technology is described in US patent 5532476, according to which a control system comprises a lever movable relative to a housing and equipped with a reflective area. Several light-emitting and light-sensing devices are arranged in the housing so as to emit light within a displacement field of the lever's reflective area during the lever's movements. The light-emitting / light-sensing device then generates an electrical signal when it detects light reflected by the lever's reflective area; this light is to be reflected back to the device only when the lever is in its "neutral" position or near this "neutral" position.

[0010] The present invention then aims to provide an alternative solution for monitoring the integrity of a control device by exploiting a three-dimensional measurement of a magnetic field modified by the movement of a lever of this control device.

[0011] The present invention relates first of all to a control device having a lever articulated to a support, the lever being having at least one magnetic dipole and movable at least in rotation relative to the support around an X,Y axis, the control device comprising a measuring device configured to measure three components of a magnetic field B generated by said at least one magnetic dipole at a position of the measuring device, the control device comprising a control system for monitoring the control device.

[0012] The lever may comprise a single magnetic dipole or several magnetic dipoles, arranged for example at one end of the lever. The magnetic dipole(s) may comprise a permanent magnet or an electromagnet, for example.

[0013] The measuring device is configured to measure the magnetic field B generated by the magnetic dipole(s) and captured at a fixed position relative to the support, namely the position of this measuring device. The variations in this magnetic field B reflect the displacements of the magnetic dipole(s) relative to the support, and consequently, the displacements of the lever.

[0014] The measuring device may comprise a single measuring device. Alternatively, the measuring device may comprise several measuring devices. The measuring devices may be used simultaneously to provide a measurement of the magnetic field B established in a known manner by combining the measurements of these three measuring devices, for example by calculating the average or median value, or in redundancy to compensate for a possible failure of one of the measuring devices.

[0015] Each of the three components of the magnetic field B can be measured independently by the measuring device along three non-coplanar measurement directions U, V, W, forming a frame of reference (U, V, W) fixed to the support. These three measurement directions U, V, W are, for example, orthogonal to each other. One or more of these three measurement directions U, V, W may optionally be parallel to one or more axes of mobility of the lever relative to the support. The measuring device may include three magnetic sensors, for example, Hall effect sensors, associated respectively with the three measurement directions U, V, W in order to measure each of the three components of the magnetic field B.

[0016] The control device according to the invention is remarkable in that the control system is configured to signal an anomaly by means of an alarm when a first predetermined function F 1 is greater than a first magnetic field threshold, for a duration greater than a duration threshold, and in that the predetermined function is a function of the three measured components of a current magnetic field Bc and an estimated orientation of the lever, the first predetermined function F 1 having a value of a first norm N1 of a first vector difference between the current magnetic field Bc and a first reference magnetic field Bref 1 determined at the position of the measuring device, the first reference magnetic field Bref 1 being relative to the estimated orientation.

[0017] The first predetermined function F1 characterizes the first vector difference between the current magnetic field Bc and the first reference magnetic field Bref1, which has been previously determined at the position of the measuring device for the estimated orientation of the lever. This first reference magnetic field Bref1 has been previously defined for a control device guaranteed to be fault-free, for several reference orientations of the lever relative to the X,Y axis or axes. A first stored database thus associates several values ​​of the first reference magnetic field Bref1 with the reference orientations of the lever. Thus, each reference orientation is associated with three components of the first reference magnetic field Bref1, for example, according to the three measurement directions U, V, W. The reference orientations of the lever stored in The first database covers all possible orientations of the lever relative to the X,Y axis or axes, taking into account a predefined discretization step.

[0018] This first predetermined function F 1 is therefore a function of the three measured components of the current magnetic field Bc, the values ​​of the first reference magnetic field Bref 1 and an estimated orientation of the lever.

[0019] The orientation of the lever relative to the support can be estimated using the magnetic field B measured by the measuring device, and in particular using its three components. A computer in the control system can, using one or more stored transformation laws, estimate this orientation of the lever as a function of the three measured components of a current magnetic field Bc. The computer can alternatively be located outside the control device and, for example, be integrated into a central control system for the control device, or even into an aircraft avionics system when the control device is fitted to an aircraft.

[0020] The measuring device may also include an internal calculator to directly determine this estimated orientation of the lever as a function of the measured magnetic field B.

[0021] Alternatively, the orientation of the lever relative to the support can be measured by dedicated sensors, for example angular sensors positioned on the X,Y axis of mobility of the lever.

[0022] The first predetermined function F1 provides as a result the value of a first norm N1 of this first vector difference between the current magnetic field Bc and the first reference magnetic field Bref1 relative to the estimated orientation. This first predetermined function F1 can be calculated by the control system's computer.

[0023] This first NI norm can, for example, be a Euclidean norm or a so-called "infinite" norm, or even another norm. Furthermore, strictly positive constants a, b, and c can be used to characterize the anisotropy of the measurement precision of the measuring device. In this case, since the first vector difference is a vector with coordinates u, v, w, the first NI norm can, for example, be written according to the following formula: jç — max(a I u I, b. IFI. c. I wI ) for an infinite norm. For a Euclidean norm, the first NI norm can then be written

[0024] The control system's computer is also configured to compare this first N1 standard with a first magnetic field threshold. The first magnetic field threshold has been previously defined, for example, by testing and / or simulations. The control system thus signals an anomaly using an alarm when the = \la.u2 + b.v2 + cw The first standard N1 is above the first magnetic field threshold for a duration exceeding the time threshold. This anomaly may, in particular, be a defect in the control device, for example, a deformation or even breakage of the lever, rendering the information provided by the control device invalid.

[0025] The alarm can then signal the presence of such a fault by emitting an alert, for example visual, audible, or even haptic, to inform an operator or an external system to which the control device is connected, such as a central control system or a piloting device, or even an aircraft avionics system, of this anomaly. The use of the duration threshold advantageously prevents the emission of false alerts in the event of a transient exceedance of the first magnetic field threshold by the first NI standard, specifically for a duration less than or equal to the duration threshold.

[0026] Furthermore, when the first NI standard exceeds the first magnetic field threshold for a duration exceeding the time threshold, the control system may prevent the control device from sending a control signal relating to the estimated orientation of the lever, for example, to a machine control system, an aircraft piloting system, or any other device connected to the control device. A backup lever for the control device may optionally be available and activated to compensate for the anomaly detected on the control device lever.

[0027] The control device according to the invention may further comprise one or more of the following features, taken alone or in combination.

[0028] According to one possibility, the first reference magnetic field Bref1 relative to the estimated orientation of the lever can be determined by interpolation from the predetermined and stored values ​​of the first reference magnetic field Bref1 associated respectively with the reference orientation values ​​of the lever. In this case, the control system computer estimates, based on the predetermined and stored values ​​of the first reference magnetic field Bref1, an estimated value of the first reference magnetic field Bref1 for a reference orientation equal to the estimated orientation of the lever.

[0029] Alternatively, the first Brefl reference magnetic field relative to the estimated orientation of the lever can be selected from among the predetermined and stored values ​​of the first Brefl reference magnetic field associated respectively with the reference orientation values ​​of the lever, the selected value being associated with the reference orientation closest to the estimated orientation. In this case, the control system computer first searches for the reference orientation closest to the estimated orientation using a known method, and then selects the value of the first Brefl reference magnetic field. 1 corresponds to the reference orientation closest to the estimated orientation of the lever. The discretization step must then be defined so that the differences between two initial reference magnetic field values ​​associated with two adjacent reference orientations are less than the first magnetic field threshold. A safety margin may optionally be taken into account.

[0030] According to a possibility compatible with the previous ones, the lever can be mobile in rotation relative to the support around a single axis X.

[0031] Alternatively, the lever can be rotationally movable relative to the support about a first axis X and a second axis Y. The estimated orientation of the lever is then defined relative to the support by two angles 0,0 around the first and second axes X,Y respectively. The first and second axes X,Y can be orthogonal to each other, and possibly coplanar.

[0032] According to a possibility compatible with the preceding ones, the lever may be elongated and substantially straight, along an actuation axis Z, and movable in translation relative to the support along this actuation axis Z between a rest position, also called the "neutral position," and an actuated position. A return device, for example an elastic one, may allow the lever to automatically return to the rest position as soon as the lever is no longer being operated.

[0033] Furthermore, the control device can be configured to detect that the lever is in the actuated position when a second predetermined function F2 is less than a second magnetic field threshold, the second predetermined function F2 being a function of the three measured components of the current magnetic field Bc and the estimated orientation of the lever, the second predetermined function F2 having a second norm A2 of a second vector difference between the current magnetic field Bc and a second reference magnetic field Bref2 determined at the position of the measuring device, the second reference magnetic field Bref2 being relative to the estimated orientation of the lever.

[0034] The second reference magnetic field Bref2 has been previously defined for a control device guaranteed to be fault-free, with the lever in the actuated position along the actuation axis Z, for several reference orientations of the lever relative to the X,Y axis(es). A second stored database thus associates several values ​​of the second reference magnetic field Bref2 with the reference orientations of the lever. The reference orientations of the lever stored in the second database cover all possible orientations of the lever relative to the X,Y axis(es), taking into account the predefined discretization step.

[0035] The reference orientations of the lever stored in the second database are preferably identical to those stored in the first database. In this case, the first and second databases can form a single database storing the reference orientations of the lever and associating them respectively with several values ​​of the first reference magnetic field Brefl and several values ​​of the second reference magnetic field Bref2.

[0036] Possibly, the reference orientations of the lever stored in the first database and the second database may be different.

[0037] Like the first reference magnetic field Brefl, the second reference magnetic field Bref2 relating to the estimated orientation of the lever can be determined by interpolation from the predetermined and stored values ​​of the second reference magnetic field Bref 2 associated respectively with the reference orientation values ​​of the lever or selected from these values ​​of the second reference magnetic field according to the reference orientation closest to the estimated orientation.

[0038] The second predetermined function F2 thus makes it possible to characterize the second vector difference between the current magnetic field Bc and the second reference magnetic field Bref2 which has been previously determined at the position of the measuring device for the estimated orientation of the lever.

[0039] The second predetermined function F2 is therefore a function of the three measured components of the current magnetic field Bc, the values ​​of the second reference magnetic field Bref2, and an estimated orientation of the lever. As such, the second predetermined function F2 differs from the first predetermined function F1.

[0040] The second predetermined function F2 provides as a result the value of a second magnitude N2 of this second vector difference between the current magnetic field Bc and the second reference magnetic field Bref2 relative to the estimated orientation. This second predetermined function F2 can be calculated by the control system's computer.

[0041] Like the first NI standard, the second N2 standard can, for example, be a Euclidean standard or an infinite standard, or even another standard, possibly using strictly positive constants a', b', and c' to characterize the anisotropy of the measurement accuracy of the measuring device. In particular, the first A7 standard and the second A2 standard can be identical, with the constants a', b', and c' then being equal to the constants a, b, and c, respectively.

[0042] The control system's computer is then configured to compare this second A2 standard with a second magnetic field threshold. The second magnetic field threshold has been previously defined, for example by testing and / or simulations. The control system can then signal that the lever is in the actuated position. relative to the actuation axis Z, for example using the alarm when the second N2 standard is below the second magnetic field threshold for a duration greater than the duration threshold.

[0043] The second magnetic field threshold may be lower than, or even equal to, the first magnetic field threshold.

[0044] The present invention also relates to a method for monitoring a control device as previously described. The control device is thus equipped with a lever, articulated to a support and movable at least rotationally relative to the support around an X,Y axis. The lever is equipped with one or more magnetic dipoles, and the control device includes a measuring device configured to measure three components of a magnetic field B generated by the magnetic dipole(s) at a position of the measuring device.

[0045] A computer integrated into the control device or external to the control device may include memory or be connected to memory, this memory being able, for example, to store instructions or algorithms that enable the monitoring process to be carried out when executed. The memory may also store a computer program intended to be executed by the computer in order to implement the monitoring process.

[0046] The monitoring method according to the invention comprises the following steps: - measurement of the three components of a current magnetic field Bc by the measuring device, - Determination of an estimated orientation of the lever relative to the support, based on the three components, by applying a stored transformation law. - determination of a first Brefl reference magnetic field for the estimated orientation of the lever from predetermined and stored values ​​of the first Brefl reference magnetic field, the values ​​being associated respectively with reference orientations of the lever, - calculation of a first predetermined function Fl as a function of the three measured components of the current magnetic field Bc, the estimated orientation of the lever and the first reference magnetic field Brefl relative to this estimated orientation, the first predetermined function Fl having the value of a first norm NI of a first vector difference between the first reference magnetic field Brefl and the current magnetic field Bc, and - reporting of an anomaly using an alerter when the first predetermined function Fl is greater than a first magnetic field threshold for a duration greater than a duration threshold.

[0047] During the measurement step, the measuring device can provide, for each of the three components of the current magnetic field Bc, a raw signal or signals carrying the raw measurements of these three components obtained by the measuring device, or even respectively by the three magnetic sensors it comprises. Alternatively, the measuring device can include an internal processor to process these raw measurements, for example via conventional filtering or sampling, or even by applying transformations, and provide a processed signal or signals carrying the three components of the current magnetic field Bc based on these processed raw measurements.

[0048] During the step of determining an estimated orientation of the lever, this estimated orientation can be calculated by the computer implementing the method based on the signal(s) provided by the measuring device and carrying information relating to the three components of the current magnetic field Bc, by applying one or more transformation laws stored in the memory of the computer or connected to this computer. Alternatively, this estimated orientation of the lever can be calculated by the internal computer of the measuring device via the application of this transformation law(s) stored in a memory of the measuring device.

[0049] The computer receives one or more signals, for example from the measuring device, and emits signals, for example to the alarm, which can be electrical or optical, digital or analog.

[0050] Next, during the step of determining a first reference magnetic field Brefl, this first reference magnetic field Brefl, relative to the estimated orientation of the lever, is determined from predetermined and stored values ​​of the first reference magnetic field Brefl and associated respectively with reference orientations of the lever. The values ​​of the first reference magnetic field Brefl and the associated reference orientations are stored in a first database stored in the memory associated with the control device's computer. This first reference magnetic field Brefl has been previously defined for a control device guaranteed to be free of defects.

[0051] During this step, the first Brefl reference magnetic field relative to the estimated orientation of the lever can be determined by interpolation from the values ​​of the first Brefl reference magnetic field database and the associated lever reference orientations.

[0052] Alternatively, the estimated orientation of the lever can be compared with the reference orientations of the lever in order to find, in a known manner, the reference orientation closest to the estimated orientation. To this end, the step of determining a first reference magnetic field Brefl may include a substep of comparing the estimated orientation and the reference orientations. Then, the The value of the first reference magnetic field Brefl associated with the reference orientation closest to the orientation estimated in the first database is selected by the method according to the invention.

[0053] During the calculation step, a first predetermined function Fl is calculated and has as its value a first norm NI, for example Euclidean or infinite, of a first vector difference between the first reference magnetic field Brefl relative to the estimated orientation of the lever and the current magnetic field Bc. This first norm NI is therefore a function of the three measured components of the current magnetic field Bc, the estimated orientation of the lever and the previously determined value of the first reference magnetic field Brefl and relative to this estimated orientation.

[0054] Finally, a signaling step is performed to indicate an anomaly using an alarm when the first predetermined function F1 exceeds a first magnetic field threshold for a duration exceeding a time threshold. This signaling can be visual, using an indicator light and / or a screen on the alarm, audible, via a speaker on the alarm, or haptic.

[0055] In this way, the monitoring method according to the invention makes it possible to monitor whether the estimated orientation of the lever is valid and can be reliably used to control, for example, the movement of a machine or a vehicle, such as an aircraft. The estimated orientation is considered valid when no anomaly is detected.

[0056] These steps can be repeated consecutively, continuously, as long as the machine to which the control device is connected is working, regardless of the sequence of these steps, and the values ​​of the first predetermined function F 1.

[0057] Alternatively, these steps can be repeated several times consecutively depending on the sequence of these steps, and in particular as long as, simultaneously, the first predetermined function F 1 is greater than the first magnetic field threshold and the duration is less than or equal to the duration threshold or as long as the first predetermined function F 1 is less than or equal to the first magnetic field threshold.

[0058] Furthermore, the duration that is compared with the duration threshold is initialized to a stored initial value during a first iteration of these steps. Prior initialization can therefore be performed for this purpose before these steps are executed. This initial duration value is, for example, zero.

[0059] This duration thus acts as a counter and then increments according to the time that elapses during the execution of these steps.

[0060] An initialization of the duration to the initial value is also performed, on the one hand, at each iteration, as long as the first predetermined function Fl is less than or equal to at the first magnetic field threshold and, on the other hand, as soon as simultaneously the first predetermined function Fl becomes less than or equal to the first magnetic field threshold, after having been greater than this first magnetic field threshold, and the duration is less than or equal to the duration threshold.

[0061] The monitoring method according to the invention may further include one or more of the following features, taken alone or in combination.

[0062] According to one possibility, following the reporting of an anomaly, the monitoring process may include deactivating the lever and activating a backup lever included in the control device.

[0063] Indeed, if a fault is detected, the lever can no longer be used reliably. Therefore, the lever is deactivated, and no control signal relating to its movement is emitted by the control device. Alternatively, the control signals emitted by the control device can be ignored.

[0064] Furthermore, a backup lever of the control device can be activated by the emitting of an activation signal by the computer. The backup lever can then be put into operation for use by an operator as a replacement for the defective lever. In this way, the control device can still, thanks to the backup lever, control, for example, the movement of a machine or vehicle, by emitting a control signal according to the movement(s) of this backup lever.

[0065] According to a possibility compatible with the preceding ones, the monitoring method may include additional steps when the lever is movable in translation along an actuation axis Z between a rest position and an actuated position, the lever being elongated along this actuation axis Z. These additional steps make it possible to determine that the lever is in the actuated position.

[0066] First, a second reference magnetic field Bref 2, relative to the estimated orientation, is determined by the computer. This second reference magnetic field Bref2 is determined from predetermined and stored values ​​of the second reference magnetic field associated respectively with reference orientations of the lever. The second reference magnetic field Bref 2 characterizes the actuated position along the actuation axis Z of the lever, the control device being guaranteed to be fault-free. The value of this second reference magnetic field Bref2, relative to the estimated orientation, can be determined, as for the first reference magnetic field Bref h, by interpolating the predetermined and stored values ​​of the second magnetic field, or selected from among these predetermined and stored values ​​of the second reference magnetic field according to the reference orientation closest to the estimated orientation of the lever.

[0067] Next, a calculation of a second predetermined function F 2 is carried out by the computer as a function of the three measured components of the current magnetic field Bc, the estimated orientation of the lever and the second reference magnetic field Bref 2 relative to this estimated orientation.

[0068] This second predetermined function F 2 has the value of a second norm N 2, for example Euclidean or infinite, of a second vector difference between the second reference magnetic field Bref 2 and the current magnetic field Bc.

[0069] Finally, a determination of the actuated position of the lever is carried out when the second predetermined function F 2 is less than a second magnetic field threshold.

[0070] These steps are preferably repeated several times consecutively and continuously.

[0071] The invention and its advantages will become apparent in more detail in the following description, with illustrative examples given by reference to the accompanying figures, which represent: - [Fig. 1], a view of a control device according to the invention, - [Fig. 2], a view of a control device according to the invention, and - [Fig.3], a synoptic diagram of a process according to the invention.

[0072] Elements present in several separate figures are assigned one and the same reference.

[0073] Figures 1 and 2 represent two examples of a control device according to the invention.

[0074] Regardless of the embodiment of the invention, a control device 10 comprises a support 12 and a lever 11 articulated to this support 12, and movable at least in rotation relative to this support 12 around at least one axis of mobility, or even several axes of mobility. The lever 11 is provided with one or more magnetic dipoles 14, positioned, for example, at one of its ends. A magnetic dipole 14 may comprise a permanent magnet or an electromagnet configured to be powered by an electric current.

[0075] The control device 10 includes at least one measuring device 21-23 configured to measure three components of a magnetic field B generated by the magnetic dipole(s) 14 at the position of this measuring device 21-23. The measuring device 21-23 may include three magnetic sensors in order to measure these three components of a magnetic field B respectively. These magnetic sensors are, for example, Hall effect sensors and can thus form a three-axis Teslameter.

[0076] These three components of the magnetic field B are measured respectively along three non-coplanar measurement directions U,V,W, forming a reference frame (U,V,W) attached to support 12. These three measurement directions U,V,W are for example orthogonal in pairs.

[0077] Each magnetic sensor can provide a raw signal carrying the raw measurements taken by that magnetic sensor. The measuring device 21-23 can also include an integrated computer to process these raw measurements, for example via conventional filtering or sampling, or even the application of transformations, and provide a processed signal carrying these processed raw measurements.

[0078] The control device 10 also includes a control system 30 configured to monitor the integrity of the control device 10. The control system 30 may include a computer 33 and an alarm 35.

[0079] The control device 10 may include a housing 13 in which are arranged, at least partially, the lever 11, the magnetic dipole(s) 14, and the measuring device(s) 21-23. The support 12 is then integral with the housing 13. The housing 13 may include a conventional magnetic insulator so that the interior of this housing 13 is magnetically isolated from the external environment, and thus protected, for example, from the Earth's magnetic field or from any magnetic field in which the control device 10 according to the invention may be positioned. In this case, the measuring device 21-23 can measure the magnetic field B generated by the magnetic dipole(s) 14 without it being disturbed or modified by another magnetic field.

[0080] The control device 10 according to the invention can be integrated into or connected to a machine, for example, to control the movements of a machine element, or even the entire machine. The control device 10 according to the invention can also be integrated into a vehicle, in particular an aircraft. The control device 10 can, for example, be connected, by a wired or wireless link, to an aircraft's flight control system to control the aircraft's movements.

[0081] According to a first example shown in [Fig. 1], the lever 11 is free to rotate relative to the support 12 about a first axis X and a second axis Y. The first and second axes X,Y are not parallel, and are, for example, perpendicular to each other. The control device 10 may include a first elastic return device 18 configured to maintain or return the lever 11 to an equilibrium position about the first and second axes X,Y. The control device 10 according to this first example includes a single measuring device 21 positioned in the housing 13. The control system 30 is arranged inside the housing 13 of the control device 10.

[0082] According to this first example, the three measurement directions U,V,W are not parallel to the first and second axes X,Y.

[0083] According to a second example shown in [Fig. 2], the lever 11 is elongated along an actuation axis Z. The lever 11 is rotationally movable relative to the support 12 about a first axis X and a second axis Y, which are not parallel, or even perpendicular, to each other, and also in translation along the actuation axis Z between a rest position and an actuated position. The actuation axis Z intersects a plane formed by the first and second axes X, Y. According to this second example, the three measurement directions U, V, W are respectively parallel to the first and second axes X, Y and to the actuation axis Z when the lever 11 is in an equilibrium position about the first and second axes X, Y.

[0084] The control device 10 includes a first elastic return device 18 configured to return the lever 11 to the equilibrium position about the first and second axes X,Y, and a second elastic return device 19 configured to maintain or return the lever 11 to the neutral position about the actuating axis Z. The control device 10 includes three measuring devices 21-23 positioned at different locations in the housing 13. These three measuring devices 21-23 can be used simultaneously to provide a measurement of the magnetic field B established in a known manner by combining the measurements of these three measuring devices 21-23, or in redundancy to compensate for a possible failure of one of these measuring devices 21-23. The control system 30 is arranged outside the housing 13 of the control device 10.

[0085] The first and second elastic return devices 18,19 may include, for example, one or more springs.

[0086] According to the two examples shown, the control device 10 comprises a control member 15 integral with the lever 11, and fixed to the lever 11 at an end opposite to the end carrying the magnetic dipole 14. The control member 15 allows an operator to move the lever 11 around the first and / or second axis X,Y, or even along the actuation axis Z if applicable. The control member 15 shown in Figures 1 and 2 can be manipulated using a finger, for example, the thumb of an operator. Alternatively, a control member 15 may include a gripping area for holding and moving using the hand of an operator.

[0087] Regardless of the two examples shown, the alarm 35 of the control system 30 may include one or more indicator lights, a screen, and / or a loudspeaker. The computer 33 of the control system 30 may include, for example, at least one processor, or even at least one memory, at least one integrated circuit, at least one programmable system, at least one logic circuit; these examples do not limit the scope given to the term "computer." The term "processor" may refer to a central processing unit known by the acronym CPU, a graphics processing unit (GPU), or a known digital unit.

[0088] The computer 33 is connected by wired or wireless means to the measuring device 21-23 and to the alarm 35. Signals, electrical or optical, analog or digital, can then be exchanged between the computer 33 and, on the one hand, the measuring device 21-23 and, on the other hand, the alarm 35.

[0089] In addition, instructions or a computer program can be stored in a memory of the computer 33 or in a memory linked to this computer 33. The computer 33 can then execute these instructions or this computer program to implement a method of monitoring the control device 10 in order to monitor its integrity.

[0090] Figure 3 represents a block diagram of this method for monitoring the control device 10. This method may include the following steps.

[0091] First, a measurement 110 of the three components of a current magnetic field Bc generated by the magnetic dipole 14 is carried out by the measuring device 21-23. The measuring device 21-23 can transmit to the computer 33 a signal carrying information relating to these three components of the current magnetic field Bc.

[0092] Next, a determination 120 of an estimated orientation of the lever 11 with respect to the support 12 is carried out for example by the computer 35. This estimated orientation of the lever 11 is determined as a function of the three components of the current magnetic field Bc using a transformation law stored in the memory connected to the computer 35 or the memory of the computer 35.

[0093] A determination 130 of a first reference magnetic field Brefl for the estimated orientation is then performed by the computer 35 from predetermined and stored values ​​of the first reference magnetic field, the three components of a current magnetic field Bc, and the estimated orientation of the lever 11. The predetermined and stored values ​​of the first reference magnetic field Brefl are associated respectively with reference orientations of the lever 11 and comprise three components along the measurement directions U, V, W for each first reference magnetic field. A predefined discretization step separates the reference orientations of the lever 11.

[0094] The predetermined and stored values ​​of this first reference magnetic field Brefl have been previously defined for a control device 10 guaranteed to be free of defects and are stored, along with the reference orientations of the lever 11, in the memory of the computer 33 or connected to the computer 33. The predetermined and stored values ​​of this first reference magnetic field Brefl thus characterize so-called "normal" or "nominal" positions of the magnetic dipole 14, and consequently of the lever 11, namely when the lever 11, and consequently the control device 10, is functioning correctly. The predetermined and stored values ​​of this first reference magnetic field Brefl have, for example were measured by the measuring device 21-23 and together with the reference orientations form a first database.

[0095] The first reference magnetic field Brefl relating to the estimated orientation of the lever 11 can be determined by the computer 33 by interpolation from these values ​​of the first reference magnetic field Brefl and the associated reference orientations of the lever stored to deduce the first reference magnetic field Brefl corresponding to the estimated orientation of the lever 11.

[0096] Alternatively, a substep comparing the estimated orientation of the lever 11 with the reference orientations in the first database can be performed by the computer 33 in order to find, in a known manner, the reference orientation closest to the estimated orientation. Then, a substep selecting the value of the first reference magnetic field Brefl associated with this reference orientation closest to the estimated orientation is performed by the computer 33.

[0097] Subsequently, a calculation 140 of a first predetermined function Fl is performed by the computer 33 as a function of the three measured components of the current magnetic field Bc, the estimated orientation of the lever 11, and the first reference magnetic field Brefl relative to the estimated orientation. The first predetermined function Fl has a first norm NI of a first vector difference between the first reference magnetic field Brefl and the current magnetic field Bc.

[0098] This first NI norm can, for example, be a Euclidean norm or a so-called "infinite" norm, or even another norm. Furthermore, the anisotropy of the measurement precision of the measuring device 21-23 can be taken into account by this first NI norm through strictly positive constants a, b, and c. In this case, the first NI norm can, for example, be written, for the first vector difference of coordinates (u,v,w) in the frame (U,V,W), according to the formulas N = max(aIuI, bI vI, cl wI ) for an infinite norm, and = for a Euclidean norm.

[0099] Finally, an anomaly is reported 150 via the alarm 35 when the first predetermined function Fl exceeds a first magnetic field threshold for a duration exceeding a time threshold. For this purpose, the computer 33 emits a signal which is transmitted to the alarm 35; this signal carries information about the presence of such an anomaly.

[0100] The first predetermined function Fl is greater than the first magnetic field threshold when the magnetic dipole 14, and therefore the lever 11, is moved from its nominal position. This state may be transient, for example during manipulation and movement of the lever 11. Thus, if this state is maintained for a duration less than the duration threshold, no anomaly is reported. On the other hand, if this state is maintained for a duration greater than the duration threshold, then lever 11 has remained away from the nominal position for too long, which may be a sign of the presence of a defect, such as a deformation or breakage of lever 11.

[0101] This signal 150 thus allows the anomaly to be reported to an operator visually, audibly, or even haptically. In this way, the monitoring method according to the invention makes it possible to monitor that the estimated orientation of the lever 11 conforms to the nominal positions and is therefore valid.

[0102] In this case, the control device 10 can then emit a signal carrying information relating to this estimated orientation of the lever 11 which can be reliably used to control, for example, the movement of a machine or a vehicle.

[0103] These steps 110-150 can be applied to the two examples of control device 10 shown in Figures 1 and 2, in particular independently of a translational mobility of the lever 11 along the actuation axis Z.

[0104] These steps 110-150 can be repeated several times consecutively, depending on their sequence, and in particular as long as the lever 11 is transiently displaced from its nominal position, namely, that the first predetermined function Fl is greater than the first magnetic field threshold and the duration is less than or equal to the duration threshold. These steps 110-150 can also be repeated as long as the lever 11 is close to its nominal positions, namely, that the first predetermined function F1 is less than or equal to the first magnetic field threshold. The duration threshold is, for example, equal to 500 milliseconds.

[0105] Furthermore, the method according to the invention may include an initialization 100 of the duration during which this method takes place. During this initialization, the duration is modified to be equal to an initial value, stored in the memory of the computer 33 or connected to the computer 33. This initial value of the duration is equal, for example, to zero.

[0106] This initialization 100 can be carried out via the calculator 33, during a first iteration of these steps 110-150.

[0107] An initialization 100 can also be performed at each iteration of these steps 110-150, as long as the lever 11 is close to its nominal positions, namely as long as the first predetermined function F7 is less than or equal to the first magnetic field threshold. An initialization 100 can also be performed as soon as the lever 11 approaches its nominal positions after having deviated from them, namely as soon as the first predetermined function F7 becomes less than or equal to the first magnetic field threshold, after having been greater than this first magnetic field threshold, the duration being less than or equal to the duration threshold. Thus, the duration is not initialized as long as the lever 11 is transiently deviated from its nominal position, namely that the first predetermined function F 1 is greater than the first magnetic field threshold and the duration is less than or equal to the duration threshold.

[0108] During the execution of these steps 110-150, and in the absence of initialization 100, the duration increments according to the time that elapses.

[0109] Furthermore, in the event of a detected anomaly, the signal 150 may include a deactivation 158 of the lever 11 and an activation 159 of a backup lever 16 of the control device 10. Thus, following the detection of an anomaly, the control device 10 cannot provide, via the lever 11, reliable information regarding the estimated orientation of the lever 11. Consequently, the deactivation 158 of the lever has the effect of inhibiting the emission of a control signal from the control device 10. Alternatively, the computer 33 may emit a specific signal so that the control signals emitted by the control device 10 are ignored.

[0110] Next, the activation 159 of an emergency lever 16 is effective, for example following the emission of an activation signal by the computer 33. This activation 159 of the emergency lever 16 allows the emergency lever 16 of the control device 10 to be put into operation. In this way, the control device 10 remains functional, thanks to the emergency lever 16, to control, for example, the movement of a machine or a vehicle, by emitting a control signal according to the movement(s) of this emergency lever 16.

[0111] The monitoring method according to the invention may also include, in the case of the example of control device 10 shown in [Fig.2], the following additional steps 160-180 to determine the actuated position of the lever 11. These additional steps 160-180 make it possible to determine whether the lever 11 is in the actuated position.

[0112] First, a determination 160 of a second reference magnetic field Bref2 for the estimated orientation of the lever 11 is performed by the control unit 33, based on predetermined and stored values ​​of this second reference magnetic field associated respectively with the reference orientations of the lever 11, and as a function of the estimated orientation of the lever and the measured components of the current magnetic field Bc. This second reference magnetic field Bref2 characterizes the actuated position of the lever 11 along the actuation axis Z, the control device 10 being guaranteed to be fault-free. These predetermined and stored values ​​of the second reference magnetic field Bref2 have been previously defined for a control device 10 guaranteed to be fault-free and are stored, along with the reference orientations of the lever 11, in the memory of the control unit 33 or connected to the control unit 33.

[0113] The predetermined and stored values ​​of this second reference magnetic field Bref2 have for example been measured by the measuring device 21-23 and together with the reference orientations form a second database.

[0114] The value of this second reference magnetic field Bref2 relative to the estimated orientation can be determined, as for the first reference magnetic field Brefl, by interpolating predetermined and stored values ​​of the second magnetic field or by selecting from these values ​​of the second reference magnetic field according to the reference orientation closest to the estimated orientation of the lever IL

[0115] Next, a calculation 170 of a second predetermined function F2 is performed by the calculator 33 as a function of the three measured components of the current magnetic field Bc, the estimated orientation of the lever 11 and the predetermined and stored values ​​of the second reference magnetic field Bref2. The second predetermined function F2 has a second magnitude N2 of a second vector difference between the second reference magnetic field Bref2 and the current magnetic field Bc.

[0116] As with the first NI standard, the second N2 standard can be a Euclidean standard or an infinite standard, or even another standard. Furthermore, the anisotropy of the measurement accuracy of the measuring device 21-23 can be taken into account by means of strictly positive constants a', b' and c'. In this case, the second norm N2 can, for example, be written, for the second vector difference with coordinates (u',v',w') in the frame (U,V,W), according to the formulas ^2 = max(a.Iu 1, bI v'IcIw'I ) for an infinite norm, and 1 / --9 , for a Euclidean norm, z — ua .u +uv- + cw^ r

[0117] Finally, a determination 180 of the actuated position of the lever 11 is carried out using the computer 33 when the second predetermined function F2 is below a second magnetic field threshold

[0118] During the determination 180 of the actuated position of the lever 11, the control system 30 can signal that the lever 11 is in the actuated position along the actuation axis Z, via the alerter 35, the computer 33 emitting a signal carrying such information to the alerter 35. Alternatively, or in addition, the control device 10 can transmit a signal carrying information relating to the estimated orientation of the lever 11 and to this actuated position of the lever 11.

[0119] These additional steps 160-180 are repeated several times consecutively depending on their execution. These additional steps 160-180 can be carried out in parallel with steps 130-150 relating to the detection of an anomaly on the lever 11 or sequentially at these steps 130-150. No initialization 100 of the duration is performed based on the progress of these additional steps 160-180.

[0120] Naturally, the present invention is subject to numerous variations in its implementation. Although several embodiments have been described, it is understood that it is not conceivable to exhaustively identify all possible embodiments. It is, of course, conceivable to replace a described means with an equivalent means without departing from the scope of the present invention and the claims.

Claims

Demands

1. Control device (10) having a lever (11) articulated to a support (12), said lever (11) having at least one magnetic dipole (14) and movable at least in rotation relative to said support (12) about an axis (X,Y), said control device (10) having a measuring device (21-23) configured to measure three components of a magnetic field (B) generated by said at least one magnetic dipole (14) at a position of said measuring device (21-23), said control device (10) having a control system (30) for monitoring said control device (10), characterized in that said control system (30) is configured to signal an anomaly by means of an alarm (35) when a first predetermined function (Fl) is greater than a first magnetic field threshold for a duration greater than a duration threshold,and in that said predetermined function (Fl) is a function of said three measured components of a current magnetic field (Bc) and an estimated orientation of said lever (11), said first predetermined function (Fl) having a value of a first norm (NI) of a first vector difference between said current magnetic field (Bc) and a first reference magnetic field (Brefl) determined at said position of the measuring device (21-23), said first reference magnetic field (Brefl) being relative to said estimated orientation.

2. Control device (10) according to claim 1, wherein said lever (11) is elongated along an actuation axis (Z) and movable in translation along said actuation axis (Z) between a rest position and an actuated position.

3. Control device (10) according to claim 2, configured to detect that said lever (11) is in the actuated position when a second predetermined function (F2) is below a second magnetic field threshold, said second predetermined function (F2) being a function of said three measured components of said current magnetic field (Bc) and of said estimated orientation of said lever (11), said second predetermined function (F2) having a value of a second norm (N2) of a second vector difference between said current magnetic field (Bc) and a second reference magnetic field (Bref2) determined at said position of the measuring device (21-23), said second reference magnetic field (Bref2) being relative to said estimated orientation.

4. Control device (10) according to any one of claims 1 to 3, wherein said first reference magnetic field relating to said estimated orientation is either determined by interpolation from predetermined and stored values ​​of said first reference magnetic field (Brefl) associated respectively with reference orientation values ​​of said lever (11), or selected from said predetermined and stored values ​​of said first reference magnetic field associated respectively with reference orientation values ​​of said lever (11), said selected value being associated with said reference orientation closest to said estimated orientation.

5. Control device (10) according to any one of claims 1 to 4, wherein said first standard (NI) is expressed for a coordinate vector (u,v,w) according to the following formula max(alHl, àlvl, c.lwl ), where the constants a, b and c are strictly positive.

6. A method for monitoring a control device (10) having a lever (11) articulated to a support (12), said lever (11) having at least one magnetic dipole (14) and movable at least rotationally relative to said support (12) about an axis (X,Y), said control device (10) comprising a measuring device (21-23) configured to measure three components of a magnetic field (B) generated by said at least one magnetic dipole (14) at a position of said measuring device (21-23), characterized in that said monitoring method comprises the following steps: - measurement (110) of said three components of a current magnetic field (Bc) by said measuring device (21-23), - determination (120) of an estimated orientation of said lever (11) relative to said support (12), as a function

7. of the said three components by application of a stored transformation law, - determination (130) of a first reference magnetic field (Brefl) for said orientation estimated from predetermined and stored values ​​of said first reference magnetic field, said values ​​being associated respectively with reference orientations of said lever (H), - calculation (140) of a first predetermined function (Fl) as a function of said three measured components of said current magnetic field (Bc), of said estimated orientation of said lever (11) and of said first reference magnetic field (Brefl) relative to said estimated orientation, said first predetermined function (Fl) having as its value a first norm (NI) of a first vector difference between said first reference magnetic field (Brefl) and said current magnetic field (Bc), and - reporting (150) of an anomaly using an alerter (35) when said first predetermined function (Fl) is greater than a first magnetic field threshold for a duration greater than a duration threshold. Monitoring method according to claim 6, said lever (11) being elongated along an actuation axis (Z) and movable in translation along said actuation axis (Z) between a rest position and an actuated position, said method comprising the following additional steps for determining said actuated position of said lever (11): - determination (160) of a second reference magnetic field (Bref2) for said orientation estimated from predetermined and stored values ​​of said second reference magnetic field associated respectively with reference orientations of said lever (11), said second reference magnetic field (Bref2) characterizing said actuated position along the actuation axis (Z) of said lever (11), - calculation (170) of a second predetermined function (F2) as a function of the said three measured components of said field magnetic current (Bc), of said estimated orientation of said lever (11) and of said second reference magnetic field (Bref2), said second predetermined function (F2) having a second norm (N2) of a second vector difference between said second reference magnetic field (Bref2) and said current magnetic field (Bc), - determination (180) of said actuated position of said lever (11) when said second predetermined function (F2) is less than a second magnetic field threshold.

8. A method according to any one of claims 6 to 7, wherein said determination (130) is carried out either by interpolation from predetermined and stored values ​​of said first reference magnetic field (Brefl) associated respectively with several reference orientation values ​​of said lever (11), or by selection among said predetermined and stored values ​​of said first reference magnetic field associated respectively with several reference orientation values ​​of said lever (11), said selected value corresponding to said reference orientation which is closest to said estimated orientation.

9. A method according to any one of claims 6 to 8, wherein said signaling (150) comprises a deactivation (158) of said lever (11) and an activation (159) of a backup lever (16) included in said control device (10).

10. control method (10) according to any one of claims 6 to 9, wherein said first standard (NS) is expressed for a coordinate vector (u,v,w) according to the following formula max(«lwl,âlvl,dwl ), where the constants a, b and c are strictly positive.

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