Method for controlling the operation of an electromechanical actuator, associated electromechanical actuator, and shading device comprising such an actuator
The method adjusts motor supply voltage based on current amplitude and power thresholds to manage power consumption in electromechanical actuators, addressing efficiency and overload issues without computing resource latency.
Patent Information
- Application Number
- FR2024002029
- Authority / Receiving Office
- FR · FR
- Patent Type
- Patents
- Current Assignee / Owner
- Filing Date
- 2024-02-29
- Publication Date
- 2026-03-06
- Estimated Expiration
- 2044-02-29
AI Technical Summary
Existing methods for controlling electromechanical actuators fail to efficiently manage power consumption during overloads, leading to potential damage or disruption, and require computing resources and prohibited operating margins, reducing efficiency.
A method that adjusts the motor supply voltage based on current amplitude and power thresholds, using a motor control module with an inverter bridge and pulse-width modulation, to maintain efficient operation and prevent power overload.
Efficiently manages power consumption by adjusting motor voltage according to the actuator's environment and characteristics, preventing damage and ensuring continuous operation without computing resource latency.
Smart Images
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Abstract
Description
Title of the invention: Method for controlling the operation of an electromechanical actuator, associated electromechanical actuator and obscuring device comprising such an actuator. Technical field
[0001] The present invention relates to a method for controlling the operation of an electromechanical actuator in response to a command. It also relates to an electromechanical actuator implementing such a method. Finally, it relates to a blocking device comprising such an actuator. State of the Art
[0002] An electromechanical actuator generally comprises a brushed or brushless DC electric motor and a motor control module. The electric motor is driven in response to a command by a motor voltage based on a bus voltage value. The motor control module includes a speed controller for the rotational angular velocity of the electric motor, such as a PI (Proportional-Integral) controller or a PID (Proportional-Integral-Derivative) controller. The speed controller outputs a corrected value of the motor voltage, so as to maintain a set angular velocity of the electric motor when the electric motor is controlled.
[0003] A drawback arises in the event of a momentary or prolonged overload of the electric motor, for example due to friction or aging of certain components specific to the electromechanical actuator or to a shutter device comprising such an electromechanical actuator. In this case, the instantaneous electrical power consumed by the electromechanical actuator reaches or exceeds a predetermined maximum electrical power threshold value, which may characterize a maximum power threshold value that can be consumed by the electromechanical actuator, and / or a maximum power threshold value that can be supplied to the electromechanical actuator by an electrical power supply powering the electromechanical actuator.The instantaneous electrical power consumed can, for example, damage the electromechanical actuator, the power supply, or, if the latter has a safety mechanism, can cause the interruption of the transmission of electrical power to the electromechanical actuator.
[0004] French document FR 3 115 555 A1 describes a method for controlling the operation of a battery-powered electromechanical actuator in response to a command. This method makes it possible to reduce the electrical power The power consumed by the electromechanical actuator is kept below a predetermined maximum power threshold by determining the power consumed by the electromechanical actuator during screen movement, and then decreasing the angular velocity setpoint during screen movement, depending on whether the power consumed during screen movement reaches or exceeds the maximum power threshold. This method is generally satisfactory.
[0005] However, a drawback of this method is that, in the event of a momentary or prolonged overload of the electric motor during screen movement, this method involves at least one iteration in which the electromechanical actuator consumes a power value greater than or equal to the maximum power threshold value. This power consumption is successively reduced for each subsequent screen movement until it falls below the maximum power threshold value. If the electromechanical actuator's battery can only withstand a limited number of screen movements during which the power consumption reaches or exceeds the maximum power threshold value, other power sources may malfunction or simply stop working.For example, a PoE network switch will stop supplying power to the electromechanical actuator if the power consumption of the actuator reaches or exceeds a maximum power threshold that the PoE network switch can supply to the electromechanical actuator.
[0006] In addition, this process, which can be described as learning, requires a computing resource implemented at the application level of the control module, which may cause latency, for example at the level of the applications executed by the control module, or at the level of the power limiting function.
[0007] FR 3 135 106 A1 is also known, describing a method for controlling the operation of an electromechanical actuator powered by a power supply. This method is similar to that of FR 3 115 555 A1, and in which the maximum power threshold is configured to be below a second power threshold beyond which the power supply disconnects the power supply to the electromechanical actuator. This method is also satisfactory.
[0008] However, a disadvantage of this method is that, on the one hand, it also requires learning and computing resources, and on the other hand, it requires a prohibited operating margin between the two aforementioned power thresholds, thus reducing the efficiency of the electromechanical actuator.
[0009] US patent 2008 / 260363 A1 is also known, which describes a method for controlling the operation of an electromechanical actuator in response to a command. This method includes steps taking into account a bus voltage, in In case of risk of electrical overload. However, this document is silent on how to control the supply voltage of an electric motor belonging to the electromechanical actuator.
[0010] The present invention aims to overcome the aforementioned drawbacks and to provide a control method during operation that allows for the efficient adaptation of the supply voltage of an electromechanical actuator motor according to its environment and / or characteristics. Summary of the invention
[0011] To this end, the invention relates, according to a first aspect, to a method for controlling the operation of an electromechanical actuator in response to a command, the electromechanical actuator comprising a DC electric motor and a motor control module, the electric motor being driven, in response to the command, by a motor voltage as a function of a bus voltage value, the motor control module comprising an angular speed controller for the rotation of the electric motor, the angular speed controller delivering at its output a corrected value of the motor voltage, so as to maintain a setpoint for the angular speed of the electric motor during the control of the electric motor, the method comprising at least the following steps: - monitor the amplitude of a current passing through the electric motor when the electric motor is being controlled; - determine a maximum permissible motor voltage threshold value for the electric motor (16) as a function of the amplitude of the current through the electric motor and a predetermined maximum power threshold value; - limit the motor voltage value to the maximum motor voltage threshold value if the motor voltage value reaches or exceeds the maximum motor voltage threshold value and maintain the motor voltage value at the corrected motor voltage value if the motor voltage value is less than the maximum motor voltage threshold value.
[0012] Thanks to the invention, the value of the motor supply voltage to the actuator's electric motor can be adjusted efficiently and quickly, particularly according to the characteristics of the electric motor and / or a power supply source for the electric motor, without risk of the electrical power supplied to the motor being detrimental to its operation. The invention is particularly relevant during an overload of the electromechanical actuator's electric motor.
[0013] According to advantageous but not mandatory aspects of the invention, such a process may incorporate one or more of the following features, taken in any technically permissible combination:
[0014] - The motor control module includes an electrically powered inverter bridge by the bus voltage and an inverter bridge control circuit, and wherein the control circuit is driven in response to the command by a pulse-width modulated signal such that the pulse-width modulated signal applies the motor voltage to the electric motor, the pulse-width modulated signal being characterized by a duty cycle.
[0015] - The current flowing through the electric motor is filtered in such a way as to limit sudden changes in intensity value.
[0016] - The maximum power threshold value is equal to a power threshold value that may consume the electromechanical actuator.
[0017] - The bus voltage is supplied from a power supply source, the maximum power threshold value being determined based on a power threshold value supplied by the power supply source.
[0018] - The maximum power threshold value is determined based on a value power threshold of the power supply beyond which the power supply ceases to electrically power the electromechanical actuator.
[0019] According to a second aspect, the invention relates to an electromechanical actuator comprising a motor control module configured to implement a control method in operation as previously mentioned.
[0020] According to advantageous but not mandatory aspects of the invention, such an actuator may incorporate one or more of the following features, taken in any technically permissible combination:
[0021] - The DC electric motor is of the brushless type.
[0022] - The electromechanical actuator includes a configured motor control module to implement an operating control method as described above, in which the power supply is a direct current power supply.
[0023] - The electromechanical actuator includes a configured motor control module to implement an operational control method as described above, in which the power supply is a rechargeable or non-rechargeable battery.
[0024] According to a third aspect, the invention relates to a blackout device comprising a movable screen and a motorized drive device including an electromechanical actuator. According to the invention, the electromechanical actuator is as described above.
[0025] The actuator and the occulting device of the invention provide substantially the same advantages as the method of the invention. Brief description of the figures
[0026] The present invention will be better understood with the aid of the following description, made with reference to the accompanying figures, in which identical reference signs correspond to structurally and / or functionally identical or similar elements.
[0027] [Fig-1] Fig. 1 represents a simplified schematic view of a device blackout device comprising an electromechanical actuator according to an embodiment of the invention;
[0028] [Fig.2] The [Fig.2] represents a simplified schematic view of a motorized drive device comprising an electromechanical actuator according to an embodiment of the invention and belonging to the occulting device of the [Fig.1];
[0029] [Fig. 3] [Fig. 3] shows the electrical diagram of a motor control module of a DC electric motor belonging to the electromechanical actuator shown in [Fig. 2]; and
[0030] [Fig.4] The [Fig.4] represents a flowchart of a control method in operation of the actuator of the [Fig.2], according to an embodiment of the invention. Detailed description
[0031] Figure 1 is a simplified diagram of a closure, shading and / or solar protection device 3, this device being hereafter referred to as the "shading device". The shading device 3 is intended to be installed at an opening in a building not shown, and comprises a movable screen 2.
[0032] The present invention applies to any type of shading device, such as a motorized blind, a single or double swing motorized gate, a motorized door, or a motorized roller shutter.
[0033] The screen 2 can be a roll-up canvas, or an apron composed of stackable and / or adjustable horizontal slats or blades.
[0034] The occulting device 3 includes a motorized drive device 5.
[0035] The motorized drive device 5 includes a screen winding tube 4, an electromechanical actuator 11 and a control unit 12.
[0036] The electromechanical actuator 11 is controlled by the control unit 12. The control unit 12 can be a local control unit and / or a unit central control unit, and connected by wired or wireless link with the electromechanical actuator 11. When a local control unit and a central control unit are present, the local control unit can be controlled by the central control unit.
[0037] The electromechanical actuator 11 is preferably configured to execute the commands for unwinding or rolling up the screen 2 of the blackout device 3, which can be issued, in particular, by the local control unit and / or the central control unit.
[0038] The blackout device 3 comprises either the local control unit, or the central control unit, or the local control unit and the central control unit.
[0039] Advantageously, the local control unit is a control point, which may be fixed or portable. A fixed control point may be a control box intended to be fixed to a wall of the building or to the face of a fixed frame of a window or door of the building. By way of non-limiting example, a portable control point may be a remote control, a smartphone, or a tablet.
[0040] The winding tube 4 is arranged so as to be driven in rotation by the electromechanical actuator 11 around an axis of rotation X.
[0041] Here, the screen 2 is rollable onto the winding tube 4.
[0042] Thus, the screen 2 of the occulting device 3 is wound on the winding tube 4 or unwound around it, the winding tube 4 being driven by the motorized drive device 5, in particular by the electromechanical actuator 11.
[0043] In this way, the screen 2 is mobile between a rolled-up position, in particular high, and an unrolled position, in particular low, and vice versa.
[0044] The screen 2 winds and unwinds around the winding tube 4, the inner diameter of which is greater than the outer diameter of the electromechanical actuator 11, so that the electromechanical actuator 11 can be inserted into the winding tube 4, when assembling the blackout device 3.
[0045] Fig. 2 is a simplified diagram of a motorized drive device 5 according to one embodiment of the invention.
[0046] Hereafter, the terms "power supply", "power", "intensity", "current", and "voltage" correspond respectively, unless otherwise indicated, to "electrical power supply", "electrical power", "electrical intensity", "electrical current" and "electrical voltage".
[0047] The electromechanical actuator 11 allows the screen 2 of the occulting device 3 to be moved between a fully open position, where the screen 2 is totally wound on the winding tube 4, and a completely closed position, where the screen 2 totally blocks the opening of the building.
[0048] The electromechanical actuator 11 comprises a DC electric motor 16, with or without brushes.
[0049] Advantageously, the electric motor 16 with direct current is of the electronically commutated brushless type, also called a "BLDC" motor (acronym for the Anglo-Saxon term "Brushless Direct Current") or "permanent magnet synchronous"
[0050] Alternatively, the DC electric motor 16 is of the type with direct or indirect induction brushes, also called a "DC" motor (acronym for the Anglo-Saxon term "Direct Current").
[0051] The DC electric motor 16 comprises a rotor 16a and a stator 16b, positioned coaxially around the axis of rotation X.
[0052] In operation, the electric motor 16 is subjected to a resisting torque T exerted by the elements it must drive, in particular due to friction within the occultation device 3 and the weight and / or kinematics of the screen 2.
[0053] The electromechanical actuator 11 further comprises an electronic control unit 15.
[0054] The electronic control unit 15 includes a communication module 15a of the electromechanical actuator 11, and a motor control module 15b, which controls the electric motor 16. The motor control module 15b is configured to cooperate, that is to say, cooperates, with the communication module 15a of the electromechanical actuator 11.
[0055] The communication module 15a is configured to receive and execute control commands for the electromechanical actuator 11 transmitted by the control unit 12.
[0056] According to one embodiment of the invention, the communication module 15a is configured to transmit to the motor control module 15b a Cmd command of the electric motor 16, for example in response to a command order received from the control unit 12.
[0057] According to one embodiment of the invention, the communication module 15a is configured to transmit to the motor control module 15b a command Cmd of the electric motor 16 and an angular speed setpoint Cdv of the electric motor 16, in particular of the rotor 16a, for example in response to a command order received from the control unit 12.
[0058] The electronic control unit 15 further comprises a power supply module 14. The power supply module 14 is electrically connected to a power supply 17. The power supply 17 can be of the direct current or alternating current type, and be internal and / or external (in other words, remote) to the electromechanical actuator 11.
[0059] The power supply module 14 is configured to provide a continuous bus voltage Vbus from a power supply source 17.
[0060] According to one embodiment of the invention, the power supply 17 is a direct current power supply.
[0061] According to a variant of this embodiment, the DC power supply 17 is a PoE (Power over Ethernet) network switch connected to the power supply module 14 via an RJ45 Ethernet cable. The PoE network switch is characterized by a maximum power threshold value Pdec that it can transmit to the electromechanical actuator 11, beyond which it stops supplying power to the electromechanical actuator 11. As is known, the maximum power threshold value Pdec can be predetermined by the PoE class of the PoE network switch and be, for example, equal to 15.4 watts. Advantageously, the maximum power threshold value Pmax is determined based on the maximum power threshold value Pdec of the power supply 17, for example, equal to this Pdec value.
[0062] According to one embodiment of the invention, the power supply 17 is a battery that may be internal or external to the electromechanical actuator 11. The battery may be rechargeable or non-rechargeable. According to a variant of this embodiment in which the power supply 17 is a rechargeable battery, the power supply 17 may also include at least one photovoltaic panel electrically connected to the rechargeable battery to recharge the rechargeable battery from solar energy.
[0063] According to another embodiment of the invention, the power supply 17 is an alternating current power supply network such as the mains. In this embodiment, the power supply module 14 includes a circuit, not shown, for rectifying the alternating voltage of the power supply network, configured to transform the alternating voltage of the power supply network into direct current voltage.
[0064] The bus voltage Vbus is not constant and does not depend on the electric motor 16. The bus voltage Vbus depends on the voltage of the power supply 17. It is updated in real time to take into account voltage fluctuations of the power supply 17, for example, the mains. In other words, the bus voltage Vbus corresponds to the voltage available, at any given moment, to the electric motor 16.
[0065] The [Fig.3] is an electrical diagram of the motor control module 15b, the DC electric motor 16, and various devices of the electromechanical actuator 11.
[0066] Here, the DC electric motor 16 is of the electronically commutated brushless type.
[0067] The motor control module 15b is configured to control the operation of the electric motor 16 in response to a Cmd command. This motor control module 15b advantageously comprises a motor control circuit 40 and a motor pilot circuit 4L
[0068] The stator 16b of the electric motor 16 comprises three coils Bl, B2, B3 sequentially supplied by the motor control circuit 41, which generates a rotating electromagnetic field causing the rotor 16a to rotate, the rotor 16a comprising permanent magnets orienting themselves in the direction of the electromagnetic field.
[0069] The motor control circuit 41, also called an "inverter" in the case of an electronically commutated brushless electric motor, comprises a switching circuit (not shown) forming a three-phase inverter bridge (also called a "three-phase H-bridge"), and a control circuit for the three-phase inverter bridge (not shown). The three-phase inverter bridge is electrically powered by the available bus voltage Vbus supplied by the power supply module 14, the value of the Vbus voltage being defined with respect to a reference voltage Gnd.As is known, the control circuit of the three-phase inverter bridge receives as input a PWM (Pulse Width Modulated) signal from the motor control circuit 40, the PWM signal being characterized by a duty cycle RC configured to cut the bus voltage Vbus, so as to apply to the electric motor 16 a voltage whose average value varies the angular speed of the electric motor 16.
[0070] The motor control circuit 41 includes switches not shown enabling the sequential supply of the three coils Bl, B2, B3.
[0071] Here, the switches of the motor control circuit 41 are MOSFET-type transistors (Metal Oxide Semiconductor Field Effect Transistor), and there are six of them. The type and number of switches in the control circuit are not limiting. In particular, the switches of the motor control circuit 41 may be IGBT-type transistors (Insulated Gate Bipolar Transistor).
[0072] For the electric motor 16 to operate, the successive supply of the three coils Bl, B2, B3 must be controlled synchronously with the position of the rotor 16a.
[0073] The motor control circuit 40 includes a digital processing unit (not shown). The digital processing unit is provided with a processor (not shown) comprising an angular speed controller 44 for the electric motor 16.
[0074] The rotor 16a of the electric motor 16 is coupled to the winding tube 4 and can rotate the winding tube at a constant angular speed when a signal characterized by a constant DC voltage, or a PWM signal characterized by a constant duty cycle, is applied to the electric motor 16. Changing the amplitude of the DC voltage or the duty cycle of the PWM signal applied to the electric motor 16 changes the angular speed. Furthermore, the electric motor 16 can change the direction of rotation in response to a change in the polarity of the DC voltage or the PWM signal applied to the electric motor 16.
[0075] For the purposes of the present invention, an angular velocity setpoint is neither a motor voltage driving an electric motor in response to a command, nor a PWM signal driving an electric motor in response to a command. Indeed, an angular velocity setpoint Cdv is a numerical value generally expressed in revolutions per minute or "rpm", corresponding to an angular velocity that one wishes to impose on the rotor 16a of the electric motor 16.
[0076] The digital processing unit includes an input equipped with an analog-to-digital converter (ADC). The input equipped with the analog-to-digital converter (ADC) is arranged to transmit a signal to the processor of the digital processing unit, from the signal it receives.
[0077] The electromechanical actuator 11 further comprises a device 42 for determining the angular position of the rotor 16a. The determining device 42 is configured to cooperate, that is to say, works together with the motor control module 15b. The determining device 42 and the motor control module 15b are configured together to determine the angular position of the rotor 16a.
[0078] In one embodiment of the determination device 42, the determination device 42 may be of the magnetic type and comprise an encoder wheel (not shown) and one or more sensors CpA, CpB, in particular Hall effect sensors. The encoder wheel is connected to an axial end of the rotor 16a of the electric motor 16. Furthermore, the sensor(s) CpA, CpB are mounted on an electronic board of the electronic control unit 15. The type of determination device 42 is not limiting and may be different, in particular of the optical type, for example, an encoder equipped with one or more optical sensors.
[0079] In an embodiment of the determination device 42 specifically associated with an electronically commutated brushless electric motor 16 whose stator 16b comprises three three-phase coils B1, B2, B3, the determination device 42 comprises two sensors, in particular Hall effect sensors, Each sensor is positioned at a corresponding coil. The two sensors are configured to cooperate, that is, they work with the motor control module 15b so that the motor control module 15b can determine the angular position of the rotor 16a from signals transmitted by the sensors. The number of sensors on the electric motor 16 used to determine the angular position of the rotor 16a is not limited, and in particular can be three.
[0080] In another embodiment, the motor may also be without sensors for determining the angular position of the rotor 16a. The determination of the angular position of the rotor 16a can be implemented by other measurement means, for example, by determining the electromotive force of the electric motor 16.
[0081] The motor control module 15b further includes a rotor angular velocity determination unit 43 for the rotor 16a. The determination unit 43 is configured to cooperate with the rotor angular position determination device 42 for the rotor 16a. The determination unit 43 and the determination device 42 are configured to determine the rotational angular velocity of the rotor 16a from variations in the rotor angular position 16a over time.
[0082] The motor control circuit 40 further includes an angular speed controller 44, such as a PI (Proportional-Integral) controller or a PID (Proportional-Integral-Derivative) controller. The angular speed controller 44 is configured to cooperate, that is, works in conjunction with the rotor angular speed determination unit 43 of the rotor 16a.
[0083] According to one embodiment of the invention, the angular speed controller 44 is further configured to cooperate, i.e., cooperates with the communication module 15a. The angular speed controller 44 receives as input the angular speed determined by the determining unit 43, and an angular speed setpoint Cdv imposed either by a memory of the motor control circuit 40, or by the communication module 15a. The angular speed controller 44 is configured to provide, i.e., supplies, at its output a corrected value of motor voltage Vmot_cor to adjust the motor voltage value Vmot so as to maintain the angular speed of the electric motor 16 at the angular speed setpoint Cdv of the electric motor 16.
[0084] The motor control module 15b further includes a measuring device 45 for an intensity value Imot of a current passing through the electric motor 16, in other words a current consumed by the electric motor 16.
[0085] For the purposes of the present invention, the intensity Imot through the electric motor 16 is the intensity of a current through this electric motor 16 in operation.
[0086] Advantageously, the measuring device 45 is configured to measure the intensity value Imot in real time, for example using a current probe.
[0087] According to one embodiment of the measuring device 45, the current Imot passing through the electric motor 16 is obtained by means of a positive rectified signal taking into consideration the current of each of the three coils Bl, B2, B3 of the stator 16b.
[0088] Advantageously, the motor control module 15b further comprises a filtering device 46 for the current value Imot flowing through the electric motor 16, as determined by the determining unit 45. The filtering device 46 is configured to filter the current value Imot so as to limit abrupt variations in the current value Imot, thereby improving the stability of the motor control module 15b. The filtering device 46 may be, for example, a first-order low-pass digital filter.
[0089] The motor control module 15b, in particular the motor control circuit 40, further includes a power limiting device 48. The power limiting device 48 is configured to receive, in other words receives as input the current intensity value Imot determined by the determining unit 46, and the corrected motor voltage value Vmot_cor determined by the speed corrector 44.
[0090] The power limiting device 48 is further configured to, on the one hand, calculate a maximum permissible motor voltage threshold value Vmot_max for the electric motor 16, as a function of a maximum power threshold value Pmax and the current intensity value Imot determined by the determining unit 45, and on the other hand, to limit the corrected motor voltage value Vmot_cor determined by the angular speed compensator 44 to the maximum motor voltage threshold value Vmot_max if the corrected motor voltage value Vmot_cor reaches or exceeds the maximum motor voltage threshold value Vmot_max, or to maintain the corrected motor voltage value Vmot_cor if the corrected motor voltage value Vmot_cor is less than the maximum motor voltage threshold value Vmot_max.
[0091] In other words, the maximum permissible motor voltage threshold value Vmot_max for the electric motor 16 "limits" the corrected motor voltage value Vmot_cor calculated by the angular speed controller 44 such that, if the angular speed controller 44 calculates a corrected motor voltage value Vmot_cor to be applied to the electric motor 16 lower than the maximum motor voltage threshold value Vmot_max, then there is no limiting effect and the bus voltage value applied to the electric motor 16 is the corrected motor voltage value Vmot_cor calculated by the angular speed controller 44.If, on the contrary, the angular speed compensator 44 calculates a corrected motor voltage value Vmot_cor greater than or equal to the maximum threshold value of motor voltage Vmot_max, it is the maximum threshold value of motor voltage Vmot_max that is applied to the electric motor 16, with the effect of reducing the angular speed of the electric motor 16.
[0092] Advantageously, the maximum power threshold value Pmax corresponds to a maximum power threshold value permitted by the DC power supply 17. For example, when the electromechanical actuator 11 is powered by a port of a PoE network switch whose power supply capacity is limited to 25 watts, the maximum power threshold value Pmax is predetermined to be equal to or slightly less than 25 watts. Thus, the control method during operation makes it possible to limit the power consumed by the electromechanical actuator 11 below the maximum power threshold value permitted by the DC power supply 17.
[0093] Advantageously, the maximum power threshold value Pmax is recorded in a memory of the electronic control unit 15, in particular in a memory of the motor control circuit 40.
[0094] Advantageously, the maximum power threshold value Pmax is determined to be equal to a power threshold value Pact that the electromechanical actuator 11 can consume. Thus, the motor control module 15b, in particular the motor control circuit 40, makes it possible to limit the power value consumed by the electromechanical actuator 11 to a maximum power threshold value Pact that the electromechanical actuator 11 can consume.
[0095] The motor control module 15b further includes a conversion unit 49 for converting the motor voltage value Vmot supplied by the power limiting device 48 into a PWM signal for driving the electric motor 16. The conversion unit 49 receives as input the motor voltage value Vmot determined, i.e. calculated, by the power limiting device 48, and the bus voltage value Vbus of the electric motor 16. The bus voltage value Vbus can be stored in a memory of the control module 15, or monitored so as to take into account variations in the bus voltage Vbus, in particular variations in the voltage of the power supply source 17. The conversion unit 49 provides as output the PWM signal to the motor control circuit 41, in particular the control circuit of the three-phase inverter bridge.The conversion unit 49 adjusts the duty cycle of the PWM signal according to the ratio between the bus voltage value Vbus and the motor voltage value Vmot. For example, if the conversion unit 49 receives a motor voltage value Vmot of 50 volts from the power limiting device 48, while the bus voltage value Vbus is 325 volts, the conversion unit 49 provides the three-phase inverter bridge with a PWM signal whose duty cycle RC is equal to Vbus / Vmot = 50 / 325 = 15.38%.
[0096] Advantageously, the conversion unit 49 can limit the value of the duty cycle RC of the PWM signal between a minimum threshold value PWM_min and a threshold value The maximum PWM_max value is set. For example, PWM_min is 5% and PWM_max is 95%. Limiting the duty cycle allows compliance with the cross-conductor current reading requirements of the motor control module 15b. The minimum threshold value, PWM_min, ensures the ability to read the motor current, because at 0% the switches would never close, making it impossible to read the current using the current measurement device 45 (Imot). The maximum threshold value saturates the duty cycle value of the PWM signal.
[0097] The angular velocity of a BLDC motor is directly related to the average value of the voltage applied to the motor, Vmot. Therefore, correcting the motor voltage value, Vmot, according to the available bus voltage, Vbus, ensures constant performance, regardless of the available bus voltage. If the motor voltage value, Vmot, were not corrected, there would be less dynamic range with a low available voltage and more dynamic range with a high available voltage. With voltage correction, the regulation has the same performance regardless of the supply voltage.
[0098] The conversion unit 49 can be any suitable controller, such as a programmable logic device (PLD), a microprocessor, an application-specific integrated circuit (ASIC) or a field-programmable gate array (FPGA).
[0099] In practice, the value of the current Imot through the electric motor 16 in response to the command Cmd is much greater than the value of the current through the rest of the electronic control unit 15, thus allowing a simple estimation of the power consumed by the electromechanical actuator 11 when the electric motor 16 is controlled.
[0100] One disadvantage of this control method in operation is that it is not very precise and that the value of power actually consumed by the electromechanical actuator is mechanically greater than the value of power estimated solely from the value of current Imot passing through the electric motor 16.
[0101] It is therefore advantageous to be able to propose an adjustment of the maximum power threshold value Pmax to take into account the overall, i.e. total, consumption of the electromechanical actuator 11.
[0102] Advantageously, the maximum threshold value of voltage Vmot_max applicable to the electric motor 16 determined by the power limiting device 48 is adjusted, in particular to take into account the overall / total consumption of the electromechanical actuator 11.
[0103] Advantageously, the maximum threshold voltage value Vmot_max applicable to the electric motor 16 is adjusted via a grid of values associating maximum threshold voltage values, depending on the position of the motor electric 16, in particular the position of the screen 2 of the motorized drive device 5.
[0104] Advantageously, the maximum power threshold value Pmax can be adjusted dynamically via the communication module 15a.
[0105] Advantageously, the communication module 15a is configured to receive a load shedding message, such as a radio command, for example according to an io, zigbee, etc. protocol. The load shedding message contains information for adjusting the maximum power threshold value Pmax.
[0106] According to one embodiment, the adjustment information contains a new maximum power threshold value Pmax_new intended to replace the maximum power threshold value Pmax previously recorded in a memory of the electronic control unit 15.
[0107] Alternatively, the memory of the electronic control unit includes a plurality of maximum power threshold values Pmax_l, Pmax_2, ..., Pmax_N and the adjustment information contains an adjustment order configured to select a maximum power threshold value to be adjusted, from among the plurality of maximum power threshold values Pmax_l, Pmax_2, ..., Pmax_N.
[0108] For example, the memory of the electronic control unit 15 includes a first maximum power threshold value Pmax_l corresponding to a maximum power threshold value associated with an optimal operating mode of the electromechanical actuator 11, and a second maximum power threshold value Pmax_2 associated with a limited operating mode of the electromechanical actuator 11, the value of Pmax_2 being strictly less than the value of Pmax_l. The communication module 15a receives a load shedding message including MODE_LESSING information, instructing the motor control module 15b to select the value Pmax_2.
[0109] Thus, the electromechanical actuator 11 continues to operate, but with less power, resulting in a reduced speed.
[0110] Advantageously, the load shedding message is programmed to be sent in response to a periodic event or to the fulfillment of a triggering condition.
[0111] According to one embodiment of the invention, the DC electric motor 16 is of the brushed type. According to this embodiment, the switches of the motor control circuit 41 are four in number and are arranged in an H-bridge. The switches are coupled such that, when two of the switches are conducting, a positive DC voltage is applied to the brushed DC electric motor 16 to rotate the brushed DC electric motor 16 in a first direction of rotation. When The two other switches of the H-bridge are conducting; a negative DC voltage is applied to the brushed DC electric motor 16 to rotate it in a second direction of rotation opposite to the first direction of rotation. To control the speed of the brushed DC electric motor 16, the generation unit 49 drives at least one of the H-bridge switches using the PWM signal.
[0112] The [Fig.4] is a flowchart detailing the steps of a control process in operation according to an embodiment of the invention.
[0113] The control method in operation is executed by the motor control circuit 40, in particular by the processing unit of the motor control circuit 40, in response to a Cmd command received during a prior step E00.
[0114] The control method in operation includes a first step E10 of monitoring an amplitude of a current Imot through the electric motor 16 during the control Cmd of the electric motor 16.
[0115] Advantageously, the first monitoring step E10 includes a first substep El 1 of reading a current profile through the electric motor 16, then a second substep E12 of determining the amplitude of the current Imot through the electric motor 16 from the current profile read by the first substep El 1 of reading.
[0116] Advantageously, the first stage E10 includes a substage El3 for filtering the amplitude of the current through the electric motor 16.
[0117] The in-operation control method further comprises a second step E20 for determining a maximum permissible motor voltage threshold value Vmot_max for the electric motor 16, based on the amplitude of the current Imot flowing through the electric motor 16, determined in the first step E10, and a predetermined maximum power threshold value Pmax. For example, the maximum motor voltage threshold value Vmot_max can be calculated simply using the following equation:
[0118] Vmot_max = Pmax / Imot (equation 1)
[0119] Advantageously, the second determination step E20 is implemented by the power limiting device 48.
[0120] The in operation control method further includes a third step E30 of determining a motor voltage value Vmot to be applied to the electric motor 16 such that the motor voltage Vmot allows the angular speed setpoint Cdv of the electric motor 16 to be maintained during the control Cmd of the electric motor 16.
[0121] Advantageously, the third determination step E30 is implemented by the angular velocity compensator 44, the angular velocity compensator 44 receiving input is the angular velocity setpoint Cdv and the angular velocity estimated by the determination device 43 of the angular velocity of the electric motor 16.
[0122] The in-operation control method further includes a fourth step E40 of limiting the motor voltage value Vmot, determined by the third determination step E30, to the maximum threshold value of motor voltage Vmot_max, determined by the second determination step E20, if the motor voltage value Vmot reaches or exceeds the maximum threshold value of motor voltage Vmot_max, and of maintaining the motor voltage value Vmot at the corrected value of motor voltage Vmot_cor if the motor voltage value Vmot is less than the maximum threshold value of motor voltage Vmot_max.
[0123] Advantageously, the fourth limiting step E40 includes a first substep E41 for comparing the corrected motor voltage value Vmot_cor determined by the third determination step E30 with the maximum threshold motor voltage value Vmot_max determined by the second determination step E20. If the comparison in substep E41 reveals that the corrected motor voltage value Vmot_cor reaches or exceeds the maximum threshold voltage value Vmot_max, the control method in operation implements a second substep E42 for limiting the corrected motor voltage value Vmot_cor to be applied to the electric motor 16 to the maximum threshold motor voltage value Vmot_max.If the comparison of substep E41 reveals that the corrected motor voltage value Vmot_cor is strictly less than the maximum threshold voltage value Vmot_max, the control method in operation implements a third substep E43 of maintaining the corrected motor voltage value Vmot_cor to be applied to the electric motor 16.
[0124] Advantageously, the control method in operation further includes a fifth step E50 of applying the motor voltage Vmot to the electric motor 16, the motor voltage Vmot having been determined by the power limiting device 48 during the fourth limiting step E40.
[0125] Advantageously, the fifth step E50 of applying the motor voltage Vmot includes a first substep E51 of monitoring the bus voltage Vbus, a second substep E52 of determining the duty cycle RC of a PWM signal to be applied to the electric motor 16 as a function of the value of the motor voltage Vmot determined by the fourth limiting step 40 and the value of the bus voltage Vbus determined by the first monitoring substep E51, and a third substep E53 of applying, to the electric motor 16, the motor voltage Vmot determined by the second determination substep E52.
[0126] For example, if the fourth step E40 determines a motor voltage value Vmot equal to 50 volts, and if the first substep E51 determines a voltage value of bus Vbus equals 325 volts, the second sub-step E52 determines an RC duty cycle of the PWM signal to be applied to the electric motor equal to Vbus / Vmot = 50 / 325 = 15.38%, and the third sub-step E53 applies to the electric motor 16, in particular to the motor control circuit 41, a PWM signal with a duty cycle of 15.38%.
[0127] Advantageously, the fifth step E50 of applying the motor voltage Vmot includes a fourth substep E54 of limiting the value of the duty cycle RC of the PWM signal between a minimum threshold value PWM_min and a maximum threshold value PWM_max, the value of the duty cycle RC of the PWM signal having been determined by the second substep E52. This fourth substep is then implemented before the third substep E53.
[0128] The different embodiments and variants defined above can be combined to generate new embodiments of the invention.
Claims
Demands
1. A method for controlling the operation of an electromechanical actuator (11) in response to a command (Cmd), the electromechanical actuator (11) comprising a DC electric motor (16) and a motor control module (15b), the electric motor (16) being driven, in response to the command (Cmd), by a motor voltage (V_mot) as a function of a bus voltage value (Vbus), the motor control module (15b) comprising an angular speed controller (44) for the rotation of the electric motor (16), the angular speed controller (44) outputting a corrected value of the motor voltage (Vmot_cor) so as to maintain a set angular speed (Cdv) of the electric motor (16) during the command (Cmd) of the electric motor (16), the method comprising at least the following steps: - monitoring (E10) the amplitude of a current (Imot) flowing through the electric motor (16) during the control (Cmd) of the electric motor (16);- determine (E20) a maximum permissible motor voltage threshold value (Vmot_max) for the electric motor (16) as a function of the current amplitude (Imot) through the electric motor (16) and a predetermined maximum power threshold value (Pmax); - limit (E40) the motor voltage value (Vmot) to the maximum motor voltage threshold value (Vmot_max) if the motor voltage value (Vmot) reaches or exceeds the maximum motor voltage threshold value (Vmot_max) and maintain the motor voltage value (Vmot) at the corrected motor voltage value (Vmot_cor) if the motor voltage value (Vmot) is less than the maximum motor voltage threshold value (Vmot_max).
2. A control method in operation according to claim 1, wherein the motor control module (15b) comprises an inverter bridge electrically powered by the bus voltage (Vbus) and an inverter bridge control circuit, and wherein the control circuit is driven in response to the command (Cmd) by a pulse-width modulated (PWM) signal such that the pulse-width modulated (PWM) signal applies the voltage motor (Vmot) to electric motor (16), the pulse width modulated (PWM) signal being characterized by a duty cycle (RC).
3. A control method in operation according to claim 1 or according to claim 2, wherein the current (Imot) through the electric motor (16) is filtered so as to limit abrupt variations in the intensity value (Imot).
4. A control method in operation according to any one of claims 1 to 3, wherein the maximum threshold power value (Pmax) is equal to a threshold power value (Pact) that the electromechanical actuator (11) can consume.
5. A control method in operation according to any one of claims 1 to 4, wherein the bus voltage (Vbus) is supplied from a power supply source (17), the maximum power threshold value (Pmax) being determined as a function of a power threshold value supplied by the power supply source (17).
6. A control method in operation according to claim 5, wherein the maximum power threshold value (Pmax) is determined as a function of a power threshold value (Pdec) of the power supply (17) beyond which the power supply (17) ceases to electrically supply the electromechanical actuator (11).
7. Electromechanical actuator (11) comprising a motor control module (15b) configured to implement an operating control method according to any one of claims 1 to 6.
8. Electromechanical actuator (11) according to claim 7, wherein the DC electric motor (16) is of the brushless type.
9. Electromechanical actuator (11) according to claim 7 or according to claim 8, comprising a motor control module (15b) configured to implement an operating control method according to claim 5, wherein the power supply (17) is a direct current power supply.
10. Electromechanical actuator (11) according to claim 7 or claim 8, comprising a motor control module (15b) configured to implement a control method in
11. operation according to claim 5, wherein the power supply (14) is a rechargeable or non-rechargeable type battery. A blackout device (3) comprising a movable screen (2) and a motorized drive device (5) including an electromechanical actuator (11), characterized in that the electromechanical actuator (11) is according to any one of claims 7 to 10.