Electric moving panel system
By combining a brushless DC motor and a microcontroller with zero-crossing event detection of the back EMF signal, sensorless motor rotational position tracking and anti-pinch protection are achieved, solving the problems of high cost of brushless motor systems and increased cost of sensors, and improving motor performance and stability.
Patent Information
- Application Number
- CN202422743440.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Priority Date
- 2023-11-10
- Filing Date
- 2024-11-11
- Publication Date
- 2025-12-16
- Estimated Expiration
- 2034-11-11
AI Technical Summary
Existing brushless motor systems are expensive, especially the electronic components on the inverter side, and traditional position sensors increase system costs, making it difficult to achieve accurate motor rotation position tracking and anti-pinch protection without increasing costs.
By employing a brushless DC motor and a microcontroller, and by detecting the zero-crossing event of the back EMF signal, combined with the motor phase comparator circuit, sensorless control is achieved, automatically tracking the rotational position of the motor shaft, filtering parasitic pulses, and realizing anti-pinch protection.
Without using position sensors, precise tracking of motor rotation position and anti-pinch protection are achieved, simplifying system design, reducing costs, meeting federal motor vehicle safety standards, and improving motor performance and stability.
Smart Images
Figure CN223680986U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to the field of vehicle system, especially electric mobile panel system. BACKGROUND
[0002] Sunroof motor using brushless technology should bring many advantages to customers, such as noise comfort, low radio frequency interference, light weight and small package. However, compared with similar brush motors, using brushless technology means higher cost of electronic components, especially on the inverter side. SUMMARY
[0003] An electric mobile panel system is disclosed, which is configured to automatically operate a movable panel. The electric mobile panel system includes a motor system, a motor phase comparator circuit, and a microcontroller. The motor system includes a brushless DC motor and a rotatable shaft configured to rotate in response to driving the brushless DC motor. The motor system is configured to adjust a position of a movable component in response to rotating the rotatable shaft. The motor phase comparator circuit is configured to determine a number of zero-crossing events of a first back electromotive force (BEMF), a second BEMF, and a third BEMF generated in response to driving the motor. The microcontroller is in signal communication with the motor phase comparator circuit and is configured to determine a rotational position of the rotatable shaft based on a count of each zero-crossing event corresponding to each of the first BEMF, the second BEMF, and the third BEMF. The microcontroller determines the position of the movable component based on the rotational position of the rotatable shaft without using a position sensor.
[0004] In addition to one or more of the features described above, or as an alternative. The microcontroller determines the position of the movable component with an anti-pinch function according to Federal Motor Vehicle Safety Standard (FMVSS) No. 118 (FMVSS 118) without using a position sensor.
[0005] In addition to one or more of the features described above, or as an alternative. The microcontroller allows the movable component to be automatically turned off and on based on the position of the movable component.
[0006] In addition to one or more of the features described above, or as an alternative. The microcontroller processes electrical back electromotive force signals representing the first BEMF, the second BEMF, and the third BEMF, filters spurious voltages caused by one or a combination of vibrations of the motor system and vibrations of the brushless DC motor from the back electromotive force signals, and determines the rotational position of the rotatable shaft based on the counted zero-crossing events without using a position sensor.
[0007] In addition to one or more of the features described above, or as an alternative, the motor phase comparator circuit includes a comparator including a first input configured to receive the first back EMF and the second back EMF, a second input configured to receive the third back EMF, and a logic signal configured to output a transition between a logic "0" value and a logic "1" value or a logic "1" value and a logic "0" value, wherein either transition indicates a zero-crossing event of the first back EMF, the second back EMF, and the third back EMF, respectively.
[0008] In addition to one or more of the features described above, or as an alternative, the operations performed by the microcontroller include determining when the motor is in sync or out of sync, detecting a demagnetization pulse occurring in a current back EMF of one of the first back EMF, the second back EMF, or the third back EMF when the motor is out of sync, generating a virtual zero-crossing pulse in response to detecting the demagnetization pulse, the virtual zero-crossing pulse generating the logic signal output from the comparator, and counting the logic signal output generated by the virtual zero-crossing pulse as a zero-crossing event of the current back EMF.
[0009] In addition to one or more of the features described above, or as an alternative, the movable component is a movable panel.
[0010] In addition to one or more of the features described above, or as an alternative, the motorized movable panel system further includes a gear system coupled to the rotatable shaft; and a panel adjuster including a first end coupled to the gear system and a second end coupled to the movable panel.
[0011] In addition to one or more of the features described above, or as an alternative, the panel adjuster moves the panel in a first direction in response to the rotatable shaft rotating in a first rotational direction and moves the panel in a second direction in response to the rotatable shaft rotating in a second rotational direction opposite the first rotational direction.
[0012] In addition to one or more of the features described above, or as an alternative, the brushless DC motor includes a first alternating current (AC) input configured to receive a first AC voltage having a first phase, a second AC input configured to receive a second AC voltage having a second phase, and an AC DC input configured to receive a third AC voltage having a third phase, the first AC voltage, the second AC voltage, and the third AC voltage being 120 degrees out of phase with each other.
[0013] In addition to one or more of the features described above, or as an alternative, the first alternating voltage generates a first back electromotive force, the second alternating voltage generates a second back electromotive force, and the third alternating voltage generates a third back electromotive force. BRIEF DESCRIPTION OF DRAWINGS
[0014] The following description should not be read as limiting in any way. With reference to the drawings, like elements are numbered alike:
[0015] Figure 1 is a graph depicting the three-phase voltage related to the back electromotive force (BEMF) of a motor included in an electric moving panel system according to non-limiting embodiments; Figure 1 is a graph depicting the three-phase voltage related to the back electromotive force (BEMF) of a motor included in an electric moving panel system according to non-limiting embodiments;
[0016] Figure 2 is a graph depicting the zero-crossing points related to the back electromotive force (BEMF) according to non-limiting embodiments;
[0017] Figure 3 is a block diagram of an electric moving panel system according to non-limiting embodiments that does not include a position sensor;
[0018] Figure 4 is a block diagram of an electric moving panel system according to non-limiting embodiments that does not include a position sensor; Figure 1 is a block diagram of an electric moving panel system according to non-limiting embodiments that does not include a position sensor;
[0019] Figure 5 is a graph depicting the demagnetization pulses that occur during commutation of a motor according to non-limiting embodiments. DETAILED DESCRIPTION
[0020] One or more embodiments of the disclosed device are described in detail with reference to the attached drawings figures, which are listed in the following table, and in which like reference numerals refer to like elements throughout:
[0021] Sensorless control of brushless motors is typically used for devices that do not require exact position information of the motor, such as fans and pumps. However, other applications require information of the motor rotational position to determine the position of a moving part controlled by the motor rotation. For example, automotive electric moving panels such as power windows, moon roofs, moon roofs, etc. employ anti-pinch algorithms that require knowledge of the position of the glass panel. Traditionally, a position sensor such as a Hall effect sensor is used with the power window system to determine the position of the glass panel. The addition of the Hall effect sensor adds to the system cost. Therefore, removing the expensive position sensor is a solution to bring the cost closer to that of a brushed motor. In addition, the removal of the position sensor also simplifies the overall design of the motor.
[0022] The various non-limiting embodiments described herein provide an electrically powered moving panel system that is capable of tracking the position of the rotor of a brushless motor precisely from start to stop coasting without the use of a position sensor. In this way, the position of a panel (window, moon roof, moon roof, etc.) can be tracked without the use of a sensor, thereby providing various system functions, such as anti-pinch protection functions. According to non-limiting embodiments, the anti-pinch protection functions are automatically performed in accordance with Federal Motor Vehicle Safety Standard (FMVSS) No. 118 (FMVSS 118). The anti-pinch protection functions can include, for example, automatically stopping movement of the movable component and / or automatically performing reverse movement of the movable component.
[0023] When the motor rotates, the voltage generated by the motor is opposite in direction to the applied voltage or current in the motor windings. This opposite voltage is referred to as “back electromotive force.” In a three-phase brushless DC motor, three-phase back electromotive forces 10a, 10b, and 10c are generated, with each phase 10a, 10b, 10c of back electromotive force being offset (e.g., 120 degrees) relative to one another (see Figure 1 ). A “zero crossing” 12 of each back electromotive force phase also occurs during motor rotation when the back electromotive force voltage crosses or passes through zero volts (see Figure 2 ). A zero crossing 12 occurs when the magnetic field generated by the motor rotor or armature aligns with the stator windings such that the induced voltage in the windings drops to zero.
[0024] Back electromotive force (BEMF) signals can be used in sensorless brushless motor control systems to determine whether the system is in sync or out of sync. In sync (e.g., in sync), the back electromotive force signals are consistent and predictable when the rotor is aligned with the stator magnetic field. This consistency enables the control system to accurately discern the rotor position and produce precise commutation, resulting in efficient motor operation and desired torque and speed. On the other hand, when the motor is out of sync (e.g., out of sync), the back electromotive force signals become irregular and distorted, making it difficult for the control system to accurately determine the rotor position. In this state, commutation is out of sync, resulting in poor motor performance, reduced torque, increased vibration, and a risk of motor stalling or erratic behavior.
[0025] Achieving synchronization depends on the reliability and consistency of the back electromotive force signals, which are the primary source of rotor position information for sensorless control systems. Maintaining a consistent relationship between the rotor and stator magnetic fields ensures accurate signal interpretation and proper motor function. However, rapid or significant deviations in rotor position can disrupt the quality of the back electromotive force signals, making it more difficult for the control system to maintain synchronization.
[0026] In one or more non-limiting embodiments, an electric moving panel system utilizes back electromotive force (BEMF) to determine and track the rotational position of a motor shaft without using a position sensor. The electric moving panel system described herein is also capable of filtering spurious pulses from the back electromotive force, which are referred to as “demagnetization pulses.” In this way, a more accurate rotational position of the motor (e.g., rotor or motor shaft) can be obtained.
[0027] Turning now to Figure 3 , an electric moving panel system 100 according to non-limiting embodiments of the present application is shown. The electric moving panel system 100 includes a motor system 102 configured to move a movable component 110 and an electronic control unit (ECU) 120. According to non-limiting embodiments, the movable component 110 includes an adjustable panel 112 supported in a frame 113. The adjustable panel 112 is configured to move in a first direction and a second direction opposite the first direction such that the adjustable panel 112 can be moved between a fully open position and a fully closed (end stop) position. The panel 112 can include, for example, a glass window, a sunroof, a moonroof, a movable cover, etc.
[0028] The motor system 102 includes a brushless direct current (BLDC) motor 104, a rotatable shaft 106 configured to rotate in response to actuation of the motor 102, and a gear system 107 coupled to the rotatable shaft 104. The brushless direct current motor 104 includes a first alternating current (AC) input 105a configured to receive a first AC voltage having a first phase, a second AC input 105b configured to accept a second AC voltage having a second phase, and a third AC input 105c. The first AC voltage, the second AC voltage, and the third AC voltage are phase shifted with respect to one another. For example, in at least one non-limiting embodiment, the first AC voltage, the second AC voltage, and the third AC voltage are 120 degrees out of phase with respect to one another.
[0029] The gear system 107 is configured to translate rotational motion of the motor shaft 106 to adjust a panel adjuster 114 (or armature). A first portion of the panel adjuster 114 is coupled to the gear system 107, while a second portion of the panel adjuster 112 is coupled to the panel 112. Thus, the panel adjuster 114 moves the panel 112 in a first direction in response to the rotatable shaft 106 rotating in a first rotational direction and moves the panel 112 in a second direction in response to the rotatable shaft 106 rotating in a second rotational direction opposite the first rotational direction. In one or more non-limiting embodiments, the gear system 107 is implemented as a worm drive that includes a worm 109 coupled to a worm gear 110. However, it should be appreciated that other gear systems can be implemented without departing from the scope of the present application.
[0030] An electronic control unit (ECU) 120 is configured to control the motor system 102. The ECU 120 includes a first AC output 121a configured to output a first AC voltage, a second AC output 121b configured to output a second AC voltage, and a third AC output 121c configured to output a third AC voltage. Figure 4 A non-limiting embodiment of the ECU 120 is shown in FIG. 1. The ECU 120 includes a power bridge inverter 124 and a microcontroller 122. The power bridge inverter 124 includes a power supply 125 to provide a DC voltage and a plurality of switches 128a, 128b, 128c, 128d, 128e, and 128f (collectively referred to as switches 128a-128f). The switches 128a-128f are used to convert the DC voltage to the first AC voltage, the second AC voltage, and the third AC voltage. According to a non-limiting embodiment, a first pair of switches 128a and 128b are connected to the first AC output 121a to output the first AC voltage, a second pair of switches 128c and 128d are connected to the second AC output 121b to output the second AC voltage, and a third pair of switches 128e and 128f are connected to the third AC output 121c to output the third AC voltage.
[0031] The microcontroller 122 includes a memory configured to store software instructions and a processor configured to execute the software instructions to perform various operations, including but not limited to motor position calculations, gate driver commutation management, and anti-pinch management. The microcontroller 122 also includes an output 125 configured to output a timing control signal that turns on and off the plurality of switches 128a-128f according to a timing. According to a non-limiting embodiment, the timing causes the first pair of switches 128a and 128b, the second pair of switches 128c and 128d, and the third pair of switches 128e and 128f to be out of phase with each other by 120 degrees. In this way, the first pair of switches 128a and 128b produces the first AC voltage, the second pair of switches 128c and 128d produces the second AC voltage, and the third pair of switches 128e and 128f produces the third AC voltage.
[0032] As described herein, the ECU 120 determines the rotational position of the motor shaft 106 and whether the motor is in sync (e.g., in sync) or out of sync (e.g., out of sync) based on a back electromotive force generated by the motor 104. With continued reference to Figure 2ECU 120 includes a motor phase comparator circuit 130 configured to determine a first back EMF related to the first AC voltage, a second back EMF related to the second AC voltage, and a third back EMF related to the third AC voltage. The motor phase comparator circuit 130 includes a first phase input 134a, a second phase input 134b, a third phase input 134c, and a comparator 132. The first phase input 134a is connected to the first AC output 121a and receives the first back EMF, the second phase input 134b is connected to the second AC output 121b and receives the second back EMF; and the third phase input 134c is connected to the third AC output 121c and receives the third back EMF.
[0033] The comparator 132 includes a first input 136a, a second input 136b, and an output 138. The first input 136a is connected to the first phase input 134a and the second phase input 134b, while the second input 136b is connected to the third phase input 134c only.
[0034] Thus, if the sum of the first phase input 134a and the second phase input 134b is lower than the third phase input 134c, the output 138 outputs a logic “0” value, or if the sum of the first phase input 134a and the second phase input 134b is higher than the third phase input 134c, the output 138 outputs a logic “1” value. Changes in the logic output of the back EMF comparator will be interpreted by the microcontroller as zero-crossing events.
[0035] While a single comparator 132 is shown, it should be understood that the motor phase comparator circuit 130 can include three separate comparators, each associated with a respective phase of the back EMF (e.g., the first back EMF, the second back EMF, and the third back EMF). In one or more non-limiting embodiments, the comparators include internal or external hysteresis for noise sensitivity robustness. The back EMF comparators can also be suitably set to be robust to noise and sensitive enough to detect the lowest motor speeds at the same time. Thus, the logic state (0 / 1) of the three comparators is used to count the zero-crossing events of the back EMF, and then determine the rotation of the motor shaft based on the counted zero-crossing events. In this way, the position of the moving component 110 (e.g., the panel 112) is determined.
[0036] In certain instances, commutation of the motor 104 with the inverter 124 can produce parasitic pulses. These parasitic pulses are referred to herein as “demagnetization pulses” 14a, 14b, and 14c, which can appear in the first back EMF, the second back EMF, and the third back EMF, as Figure 5The demagnetization pulses are generally undesirable because they cause false detections in the comparator 132, resulting in drift in the position estimate of the motor shaft 106.
[0037] As described herein, the motorized moving panel system 100 includes a motor system 102 having a brushless direct current (BLDC) motor 104 and a rotatable shaft 106 configured to rotate in response to driving the brushless direct current motor 104, wherein the motor system 102 is configured to adjust a position of a movable component 110 in response to rotation of the rotatable shaft 106. A motor phase comparator circuit 130 is in signal communication with the motor system 102. The motor phase comparator circuit 130 is configured to determine a plurality of zero-crossing events of a first back electromotive force (BEMF), a second BEMF, and a third BEMF generated in response to driving the motor 106. A microcontroller 122 is in signal communication with the motor phase comparator circuit 130. The microcontroller 122 is configured to determine a rotational position of the rotatable shaft 106 based on a count of each zero-crossing event corresponding to each of the first BEMF, the second BEMF, and the third BEMF. The microcontroller 122 determines the position of the movable component 110 based on the rotational position of the rotatable shaft 106 without using a position sensor. According to at least one non-limiting embodiment, the microcontroller 122 is configured to automatically close and open the movable component based on the position of the movable component 110 determined from the rotational position of the motor shaft 106. The automatic motorized adjustment operation includes an anti-pinch detection operation that can automatically stop movement and / or reverse movement of the movable component 110.
[0038] The word “approximately” is intended to encompass a degree of error with respect to a given value, which is acceptable in the context of the measurement being made with the equipment available at the time of the application is filed. For example, “approximately” can include a range of ±8% or 5% or 2% of a given value.
[0039] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present application. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and / or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.
[0040] While the present application has been described with reference to one or more example embodiments, it will be understood by those skilled in the art that various changes can be made and equivalents can be substituted for elements thereof without departing from the scope of the present application. In addition, many modifications can be made to adapt a particular situation or material to the teachings of the present application without departing from the central scope thereof. Therefore, the present application is not limited to the particular embodiments disclosed as the best mode contemplated for carrying out this application, but it includes all embodiments falling within the scope of the claims.
Claims
1. An electric moving panel system, characterized by, comprises: a motor system including a brushless direct current motor and a rotatable shaft configured to rotate in response to driving the brushless direct current motor, the motor system configured to adjust a position of a movable component in response to rotation of the rotatable shaft; a motor phase comparator circuit in signal communication with the motor system, the motor phase comparator circuit configured to determine a plurality of zero-crossing events of a first back electromotive force, a second back electromotive force, and a third back electromotive force generated in response to driving the motor; and a microcontroller in signal communication with the motor phase comparator circuit, the microcontroller configured to determine a rotational position of the rotatable shaft based on a count of each zero-crossing event corresponding to each of the first back electromotive force, the second back electromotive force, and the third back electromotive force, wherein the microcontroller determines the position of the movable component based on the rotational position of the rotatable shaft.
2. The motorized moving panel system of claim 1, wherein the microcontroller is configured to automatically close and open the movable component based on the position of the movable component.
3. The motorized moving panel system of claim 2, wherein the automatic car adjustment operation is an anti-pinch detection operation, the anti-pinch detection operation comprising at least one of automatically stopping movement of the movable component and reversing movement of the movable component.
4. The motorized moving panel system of claim 1, wherein the microcontroller processes electrical back electromotive force signals representative of the first back electromotive force, second back electromotive force, and third back electromotive force, filters spurious voltages from the back electromotive force signals caused by one or a combination of vibrations of the motor system and vibrations of the brushless direct current motor, and determines the rotational position of the rotatable shaft based on the counted zero-crossing events without using a position sensor.
5. The motorized moving panel system of claim 4, wherein the motor phase comparator circuit comprises: a comparator including a first input configured to receive the first back electromotive force and the second back electromotive force, a second input configured to receive the third back electromotive force, and an output configured to output a logic signal that transitions between a logic "0" value and a logic "1" value or a logic "1" value and a logic "0" value, wherein either of the transitions indicates the zero-crossing event of the first back electromotive force, the second back electromotive force, and the third back electromotive force, respectively.
6. The motorized moving panel system of claim 5, wherein the microcontroller performs operations comprising: determining when the motor is in sync or out of sync; detecting a demagnetization pulse appearing in a current back electromotive force of one of the first back electromotive force, the second back electromotive force, or the third back electromotive force when the motor is out of sync; generating a virtual zero-crossing pulse in response to detecting the demagnetization pulse, the virtual zero-crossing pulse generating the logic signal output from the comparator; and counting the output of the logic signal generated by the virtual zero-crossing pulse as the zero-crossing event of the current back electromotive force.
7. The motorized moving panel system of claim 1, wherein the movable component is a movable panel.
8. The motorized moving panel system of claim 7, further comprising: a gear system coupled to the rotatable shaft; and a panel adjuster comprising a first end coupled to the gear system and a second end coupled to the movable panel, wherein the panel adjuster moves the panel in a first direction in response to the rotatable shaft rotating in a first rotational direction and moves the panel in a second direction in response to the rotatable shaft rotating in a second rotational direction opposite the first rotational direction.
9. The motorized moving panel system of claim 8, wherein the brushless DC motor comprises a first AC input configured to receive a first AC voltage having a first phase, a second AC input configured to receive a second AC voltage having a second phase, and an AC input configured to receive a third AC voltage having a third phase, the first, second, and third AC voltages being 120 degrees out of phase with each other.
10. The motorized moving panel system of claim 9, wherein the first AC voltage generates the first back EMF, the second AC voltage generates the second back EMF, and the third AC voltage generates the third back EMF.