Locked-rotor protection method and device for rearview mirror motor

Abstract

The invention discloses a locked-rotor protection method and device for a rearview mirror motor, and is applied to the field of automotive electronics, and the method comprises the steps: controlling a motor to rotate according to a rearview mirror adjustment instruction after the rearview mirror adjustment instruction is received; in the rotating process of the motor, the voltage value of the position where the rearview mirror is located at each moment and the running current of the motor are obtained; determining a voltage locked-rotor mark according to the voltage value of the position of the rearview mirror at each moment; determining a current locked-rotor mark according to the motor operation current; when the voltage locked-rotor mark and the current locked-rotor mark are both preset marks, it is determined that locked-rotor happens to the motor, and the motor is controlled to stop rotating. By monitoring the voltage value and the current value at the same time, when the voltage locked-rotor mark and the current locked-rotor mark are triggered at the same time, whether locked-rotor happens to the motor or not can be accurately recognized, so that measures are taken in time, and the motor is prevented from being damaged.

Description

Technical Field

[0001] This application relates to the field of automotive electronics, and particularly to a method and device for stall protection of a rearview mirror motor. Background Art

[0002] An automotive rearview mirror includes a drive circuit and a motor, and motor stall is a common fault. The frequency and duration of stall occurrence affect the service life of the motor. Stall protection means that when the motor's speed drops sharply or it gets stuck due to an external load obstruction, the controller can detect it in time and take measures to intervene to prevent the motor from being damaged.

[0003] Currently, generally, the stall protection strategy relies on the position voltage of the rearview mirror. The software collects the position voltage of the rearview mirror to obtain the position of the rearview mirror during the adjustment stroke. If the position voltage does not change when the rearview mirror receives a drive command for adjustment, it is considered that the rearview mirror has a motor stall. However, when the ambient temperature or the controller voltage is unstable, the signal transmitted to the position voltage of the rearview mirror may have noise or fluctuations, making the change in the position voltage not obvious, thus unable to accurately reflect the actual movement state of the rearview mirror, resulting in misjudgment or failure to detect the stall in time, and further possibly causing damage to the motor.

[0004] Therefore, how to detect motor stall in time to prevent motor damage has become an urgent problem to be solved in this field. Summary of the Invention

[0005] This application provides a method and device for stall protection of a rearview mirror motor, aiming to detect motor stall in time to prevent motor damage.

[0006] To achieve the above objective, this application provides the following technical solutions:

[0007] A method for stall protection of a rearview mirror motor includes:

[0008] After receiving a rearview mirror adjustment instruction, controlling the motor to rotate according to the rearview mirror adjustment instruction;

[0009] During the rotation of the motor, obtaining the voltage value of the rearview mirror at each moment and the motor running current;

[0010] Determining a voltage stall flag according to the voltage value of the rearview mirror at each moment;

[0011] Determining a current stall flag according to the motor running current;

[0012] When both the voltage stall flag and the current stall flag are preset flags, determining that the motor has stalled and controlling the motor to stop rotating.

[0013] Optionally, before obtaining the voltage value of the rearview mirror at each moment and the motor operating current, it further includes:

[0014] Obtain the position of the rearview mirror at the current moment;

[0015] Determine whether the position of the rearview mirror at the current moment is at a specified position;

[0016] If the position of the rearview mirror at the current moment is not at the specified position, then execute the step of obtaining the voltage value of the rearview mirror at each moment and the motor operating current.

[0017] Optionally, the determining the voltage blockage flag according to the voltage value of the rearview mirror at each moment includes:

[0018] For the voltage values at each adjacent moment, calculate the difference between the voltage values at the adjacent moments in the order of acquisition time from early to late to obtain a voltage difference;

[0019] Detect whether the voltage difference is less than a preset voltage value within a preset time;

[0020] If the voltage difference is less than the preset voltage value within the preset time, then set the voltage blockage flag to a preset flag.

[0021] Optionally, the determining the current blockage flag according to the motor operating current includes:

[0022] Detect whether the motor operating current is greater than a preset blockage current threshold;

[0023] If the motor operating current is greater than the preset blockage current threshold, then record the duration during which the motor operating current is greater than the preset blockage current threshold;

[0024] Detect whether the duration is greater than a preset time;

[0025] If the duration is greater than the preset time, then set the current blockage flag to a preset flag.

[0026] Optionally, before detecting whether the motor operating current is greater than a preset blockage current threshold, it further includes:

[0027] Obtain the motor starting current and the motor rotating current;

[0028] When receiving a motor blockage instruction, control the motor to block according to the motor blockage instruction to obtain the motor blockage current;

[0029] Calculate the product of the motor starting current and the blockage coefficient to obtain the blockage current threshold;

[0030] When the locked-rotor current threshold is greater than the motor rotation current and less than the motor locked-rotor current, the locked-rotor current threshold is determined as the preset locked-rotor current threshold.

[0031] A locked-rotor protection device for a rearview mirror motor, comprising:

[0032] A rotation unit, configured to control the motor to rotate according to the rearview mirror adjustment instruction when receiving the rearview mirror adjustment instruction;

[0033] A data acquisition unit, configured to acquire the voltage value of the position where the rearview mirror is located at each moment and the motor operating current during the rotation of the motor;

[0034] A first determination unit, configured to determine a voltage locked-rotor flag according to the voltage value of the position where the rearview mirror is located at each moment;

[0035] A second determination unit, configured to determine a current locked-rotor flag according to the motor operating current;

[0036] A third determination unit, configured to determine that the motor is locked-rotor and control the motor to stop rotating when both the voltage locked-rotor flag and the current locked-rotor flag are preset flags.

[0037] Optionally, it further comprises:

[0038] A first acquisition unit, configured to acquire the position where the rearview mirror is located at the current moment;

[0039] A judgment unit, configured to judge whether the position where the rearview mirror is located at the current moment is at a specified position;

[0040] An execution unit, configured to execute the step of acquiring the voltage value of the position where the rearview mirror is located at each moment and the motor operating current if the position where the rearview mirror is located at the current moment is not at the specified position.

[0041] Optionally, the first determination unit is specifically configured to:

[0042] For the voltage values at each adjacent moment, calculate the difference between the voltage values at the adjacent moments in the order of acquisition time from early to late to obtain a voltage difference;

[0043] Detect whether the voltage difference is less than a preset voltage value within a preset time;

[0044] If the voltage difference is less than the preset voltage value within the preset time, set the voltage locked-rotor flag as a preset flag.

[0045] Optionally, the second determination unit is specifically configured to:

[0046] Detect whether the operating current of the motor is greater than a preset locked-rotor current threshold;

[0047] If the operating current of the motor is greater than the preset locked-rotor current threshold, record the duration for which the operating current of the motor is greater than the preset locked-rotor current threshold;

[0048] Detect whether the duration is greater than a preset time;

[0049] If the duration is greater than the preset time, set the current locked-rotor flag to a preset flag.

[0050] Optionally, it further includes:

[0051] A second acquisition unit, configured to acquire the starting current of the motor and the rotating current of the motor;

[0052] A locked-rotor unit, configured to, after receiving a motor locked-rotor instruction, control the motor to perform locked-rotor according to the motor locked-rotor instruction to obtain the locked-rotor current of the motor;

[0053] A calculation unit, configured to calculate the product of the starting current of the motor and a locked-rotor coefficient to obtain a locked-rotor current threshold;

[0054] A fourth determination unit, configured to, when the locked-rotor current threshold is greater than the rotating current of the motor and the locked-rotor current threshold is less than the locked-rotor current of the motor, determine the locked-rotor current threshold as the preset locked-rotor current threshold.

[0055] In the technical solution provided by this application, after receiving a rearview mirror adjustment instruction, control the motor to rotate according to the rearview mirror adjustment instruction; during the rotation of the motor, acquire the voltage value of the rearview mirror at each moment and the operating current of the motor; determine a voltage locked-rotor flag according to the voltage value of the rearview mirror at each moment; determine a current locked-rotor flag according to the operating current of the motor; when both the voltage locked-rotor flag and the current locked-rotor flag are preset flags, determine that the motor has a locked-rotor, and control the motor to stop rotating. By simultaneously monitoring the voltage value and the current value, when both the voltage locked-rotor flag and the current locked-rotor flag are triggered, it is possible to accurately identify whether the motor has a locked-rotor, so as to take timely measures to prevent the motor from being damaged. Description of the Drawings

[0056] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0057] Figure 1Flow chart of a method for protecting a rearview mirror motor against stalling provided by an embodiment of the present application;

[0058] Figure 2 Flow chart of a method for determining a voltage stalling flag provided by an embodiment of the present application;

[0059] Figure 3 Schematic diagram of a voltage-time relationship provided by an embodiment of the present application;

[0060] Figure 4 Flow chart of a method for determining a current stalling flag provided by an embodiment of the present application;

[0061] Figure 5 Flow chart of a method for determining a preset stalling current threshold provided by an embodiment of the present application;

[0062] Figure 6 Schematic diagram of a current-time relationship provided by an embodiment of the present application;

[0063] Figure 7 Flow chart of another method for protecting a rearview mirror motor against stalling provided by an embodiment of the present application;

[0064] Figure 8 Schematic diagram of the architecture of a device for protecting a rearview mirror motor against stalling provided by an embodiment of the present application. Detailed implementation manners

[0065] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts shall fall within the protection scope of the present application.

[0066] In the present application, the term "comprising", "including" or any other variant thereof is intended to cover a non-exclusive inclusion, such that a process, method, article or device comprising a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article or device. Without further limitation, an element defined by the phrase "comprising a..." does not exclude the presence of additional identical elements in the process, method, article or device comprising the element.

[0067] As Figure 1 shown, it is a flow chart of a method for protecting a rearview mirror motor against stalling provided by an embodiment of the present application, including the following steps:

[0068] S101: After receiving a rearview mirror adjustment instruction, control the motor to rotate according to the rearview mirror adjustment instruction.

[0069] Among them, the rearview mirror adjustment instruction includes but is not limited to: upward adjustment, downward adjustment, leftward adjustment, and rightward adjustment.

[0070] It can be understood that after receiving the rearview mirror adjustment instruction, control the motor to rotate according to the rearview mirror adjustment instruction, so as to change the position of the rearview mirror.

[0071] S102: During the rotation of the motor, obtain the voltage value of the rearview mirror at each moment and the motor operating current.

[0072] It can be understood that during the rotation of the motor, the position of the rearview mirror will change. The process of adjusting the rearview mirror left and right can be understood as the sliding rheostat sliding left and right. At this time, the resistance value will change, but the position supply voltage is a fixed value. The change in the resistance value will cause the voltage value of the rearview mirror at different positions to change.

[0073] S103: Determine the voltage stall flag according to the voltage value of the rearview mirror at each moment.

[0074] Among them, the voltage stall flag includes but is not limited to: VoltageFlag = 1.

[0075] It can be understood that determine the voltage stall flag according to the voltage value of the rearview mirror at each moment. Specifically, in the order of acquisition time from early to late, calculate the difference between the voltage values of two adjacent moments in turn to obtain the voltage difference, and determine the voltage stall flag according to the voltage difference.

[0076] Optionally, in another embodiment of the present application, the specific implementation manner of step S103 is as Figure 2 shown, and includes the following steps:

[0077] S201: For the voltage values of each adjacent moment, calculate the difference between the voltage values of adjacent moments in the order of acquisition time from early to late to obtain the voltage difference.

[0078] Specifically, assume that there are three moments, namely the first moment, the second moment, and the third moment. The first moment is earlier than the second moment, and the second moment is earlier than the third moment. For the voltage values of each adjacent moment, calculate the difference between the voltage values of adjacent moments in the order of acquisition time from early to late to obtain the voltage difference, that is, first calculate the difference between the voltage value of the first moment and the voltage value of the second moment, and then calculate the difference between the voltage value of the second moment and the voltage value of the third moment.

[0079] S202: Detect whether the voltage difference is less than the preset voltage value within the preset time.

[0080] If the voltage difference is less than the preset voltage value within the preset time, step S203 is executed.

[0081] Among them, the preset time period includes but is not limited to 100 ms, and the preset voltage value includes but is not limited to 0.5%.

[0082] It can be understood that if all voltage differences are not less than the preset voltage value within the preset time, it is determined that the motor is not blocked.

[0083] It should be noted that the voltage change amount is the voltage difference between two consecutive sampling moments during the movement of the rearview mirror. The voltage difference is valid only when the rearview mirror adjustment instruction controls the motor to rotate. If the rearview mirror does not move without the motor rotating, the voltage difference is always 0. At this time, it is meaningless to judge whether the voltage difference is less than the preset voltage value.

[0084] S203: Set the voltage stall flag to the preset flag.

[0085] Among them, the preset flag includes but is not limited to: 1.

[0086] Specifically, refer to Figure 3 , a schematic diagram showing a voltage-time relationship. When the voltage difference is detected to be less than the preset voltage value within the preset time, a voltage stall flag is generated, that is, the voltage stall flag is set to the preset flag.

[0087] S104: Determine the current stall flag according to the motor operating current.

[0088] Among them, the current stall flag includes but is not limited to: CurrentFlag = 1.

[0089] It can be understood that to determine the current stall flag according to the motor operating current, specifically, it is detected whether the motor operating current is greater than the preset stall current threshold. If it is greater, a debounce operation is performed to obtain a debounce result; the current stall flag is determined according to the debounce result.

[0090] Optionally, in another embodiment of the present application, the specific implementation manner of step S104, as Figure 4 shown, includes the following steps:

[0091] S401: Detect whether the motor operating current is greater than the preset stall current threshold.

[0092] If the motor operating current is greater than the preset stall current threshold, step S402 is executed.

[0093] Specifically, assume that the preset locked-rotor current threshold is 42 A and the motor operating current is 45 A. It is detected whether the motor operating current is greater than the preset locked-rotor current threshold. Obviously, the motor operating current is greater than the preset locked-rotor current threshold. Therefore, step S402 is continued to be executed.

[0094] It should be noted that if the motor operating current is not greater than the preset locked-rotor current threshold, it indicates that the motor is not locked at this time.

[0095] Optionally, before step S401, it is also necessary to pre-calculate the preset locked-rotor current threshold in order to determine whether the motor is locked according to the preset locked-rotor current threshold subsequently, so as to perform the locked-rotor protection of the motor in a timely manner. Therefore, in another embodiment of the present application, a method for determining the preset locked-rotor current threshold is provided, as Figure 5 shown, including the following steps:

[0096] S501: Obtain the motor starting current and the motor rotating current.

[0097] Among them, after receiving the rearview mirror adjustment instruction and before the motor starts to rotate, there will be a relatively large motor starting current. At this time, the motor starting current can be obtained. After the motor starts to rotate, the current of the rearview mirror driving motor will quickly drop to a stable current for operation. At this time, the obtained current is the motor rotating current.

[0098] S502: After receiving the motor locked-rotor instruction, control the motor to be locked according to the motor locked-rotor instruction to obtain the motor locked-rotor current.

[0099] Among them, the motor locked-rotor current is 5 to 12 times the rated current of the motor. However, due to different motor powers and processing technologies, the relationship between the motor locked-rotor current and the rated current cannot be determined. Therefore, it is necessary to make the motor locked-rotor at this time to obtain the motor locked-rotor current.

[0100] S503: Calculate the product of the motor starting current and the locked-rotor coefficient to obtain the locked-rotor current threshold.

[0101] Among them, the value range of the locked-rotor coefficient is (0, 1).

[0102] Optionally, the locked-rotor coefficient needs to be determined according to the working conditions of the actual load, and the default value is set to 0.6.

[0103] In step S503, the specific expression form of calculating the product of the motor starting current and the locked-rotor coefficient to obtain the locked-rotor current threshold is as shown in formula (1).

[0104] Motor locked-rotor current threshold = Motor starting current × Locked-rotor coefficient (1)

[0105] S504: When the locked-rotor current threshold is greater than the motor running current and less than the motor locked-rotor current, determine the locked-rotor current threshold as the preset locked-rotor current threshold.

[0106] It can be understood that in the motor protection system, the setting of the locked-rotor current threshold should be greater than the motor running current but less than the motor locked-rotor current to ensure that the system will not be triggered for protection erroneously (to avoid power-off during the normal startup process), and can cut off the power supply in time when the current is too large to prevent the motor from being damaged due to overload. Such a setting can ensure the normal current fluctuation of the motor during startup, and provide effective protection when a locked-rotor or abnormality occurs, extending the service life of the motor and ensuring its safe operation.

[0107] S402: Record the duration during which the motor running current is greater than the preset locked-rotor current threshold.

[0108] S403: Detect whether the duration is greater than the preset time.

[0109] If the duration is greater than the preset time, execute step S404.

[0110] Optionally, if the periodic sampling is performed every 10 ms, the preset time can be set to 100 ms.

[0111] It should be noted that detecting whether the duration is greater than the preset time can prevent misjudgment of the locked-rotor event in some abnormal scenarios where the voltage is overvoltage or there is external interference, resulting in a sudden increase in the motor drive current. If the duration is not detected whether it is greater than the preset time, there may be a situation where a locked-rotor is considered to occur in a non-locked-rotor scenario, ultimately misjudging the occurrence of a locked-rotor, affecting the normal function of the rearview mirror and causing a poor user experience.

[0112] S404: Set the current locked-rotor flag to the preset flag.

[0113] Specifically, refer to Figure 6 , a schematic diagram showing a current-time relationship. When the duration during which the motor running current is greater than the preset locked-rotor current threshold is greater than the preset time, set the current locked-rotor flag to the preset flag.

[0114] S105: When both the voltage locked-rotor flag and the current locked-rotor flag are the preset flags, determine that the motor has a locked-rotor, and control the motor to stop rotating.

[0115] It can be understood that when both the voltage locked-rotor flag and the current locked-rotor flag are the preset flags, determine that the motor has a locked-rotor and control the motor to stop rotating, thereby realizing the locked-rotor protection of the motor.

[0116] As can be seen from the above, by combining the voltage value at the position where the rearview mirror is located and the motor operating current, the function of protecting the rearview mirror motor from stalling can be effectively realized under the conditions of large temperature differences, load mismatches, structural failures, component wear, power supply failures, etc. And it can effectively prevent the mis-triggering of the rearview mirror stalling protection logic, resulting in the inability to adjust the rearview mirror normally and affecting the normal function of adjusting the direction of the rearview mirror.

[0117] In summary, by simultaneously monitoring the voltage value and the current value, when the voltage stalling flag and the current stalling flag are triggered simultaneously, it is possible to accurately identify whether the motor is stalled, and thus take timely measures to prevent the motor from being damaged.

[0118] As Figure 7 shown, the flowchart of another method for protecting the rearview mirror motor from stalling provided by the embodiment of the present application includes the following steps:

[0119] S701: After receiving the rearview mirror adjustment instruction, control the motor to rotate according to the rearview mirror adjustment instruction.

[0120] It should be noted that the specific implementation manner of step S701 can be correspondingly referred to step S101, which will not be elaborated here.

[0121] S702: During the rotation of the motor, obtain the position where the rearview mirror is located at the current moment.

[0122] S703: Determine whether the position where the rearview mirror is located at the current moment is at a specified position.

[0123] If the position where the rearview mirror is located at the current moment is not at the specified position, then execute step S704.

[0124] Among them, the specified position indicates the end position of the rearview mirror moving to a certain direction of the stroke.

[0125] It can be understood that if the position where the rearview mirror is located at the current moment is at the specified position, the rearview mirror controller will no longer issue the rearview mirror adjustment instruction in this direction, and the motor will also stop rotating to protect the rearview mirror drive motor and the limiter on the mechanical structure.

[0126] In step S703, to determine whether the position where the rearview mirror is located at the current moment is at the specified position, specifically, taking the left and right adjustment of the rearview mirror as an example, assuming that when adjusting to the leftmost end, the angle between the mirror surface and the horizontal axis is a°; when adjusting to the rightmost end, the angle between the mirror surface and the horizontal axis is b°; the angle between the mirror surface at the position where the rearview mirror is located at the current moment and the horizontal axis is x°. If |x - a| < A or |x - b| < B, and the values of A and B are generally less than 3° (the specific values of A and B need to be determined according to the actual load movement deviation of the rearview mirror), then it is considered to have moved to the end of the stroke.

[0127] Optionally, the included angle value can also be calculated from the position voltage or determined by the position voltage.

[0128] S704: Obtain the voltage value of the position where the rearview mirror is located at each moment and the motor running current.

[0129] It should be noted that the specific implementation manner of step S704 can be correspondingly referred to step S102, which will not be elaborated here.

[0130] S705: Determine the voltage stall flag according to the voltage value of the position where the rearview mirror is located at each moment.

[0131] It should be noted that the specific implementation manner of step S705 can be correspondingly referred to step S103, which will not be elaborated here.

[0132] S706: Determine the current stall flag according to the motor running current.

[0133] It should be noted that the specific implementation manner of step S706 can be correspondingly referred to step S104, which will not be elaborated here.

[0134] S707: When both the voltage stall flag and the current stall flag are preset flags, determine that the motor is stalled and control the motor to stop rotating.

[0135] It should be noted that the specific implementation manner of step S707 can be correspondingly referred to step S105, which will not be elaborated here.

[0136] In summary, by determining whether the current position of the rearview mirror has reached the specified position, only when it has not reached the specified position, the voltage value of the rearview mirror at each moment and the motor running current are obtained. This can effectively protect the rearview mirror motor and the mechanical limiter, and avoid excessive operation of the motor or damage to the limiter.

[0137] As Figure 8 shown, it is a schematic structural diagram of a stall protection device for a rearview mirror motor provided by an embodiment of the present application. The device includes: a rotation unit 100, a data acquisition unit 200, a first determination unit 300, a second determination unit 400, and a third determination unit 500.

[0138] The rotation unit 100 is configured to control the motor to rotate according to the rearview mirror adjustment instruction when receiving the rearview mirror adjustment instruction.

[0139] The data acquisition unit 200 is configured to obtain the voltage value of the position where the rearview mirror is located at each moment and the motor running current during the rotation of the motor.

[0140] The first determination unit 300 is configured to determine the voltage stall flag according to the voltage value of the position where the rearview mirror is located at each moment.

[0141] The first determination unit 300 is specifically configured to: for the voltage values at each adjacent moment, calculate the difference between the voltage values at adjacent moments in the order of acquisition time from early to late to obtain a voltage difference; detect whether the voltage difference is less than a preset voltage value within a preset time; if the voltage difference is less than the preset voltage value within the preset time, set the voltage stall flag to a preset flag.

[0142] The second determination unit 400 is configured to determine a current stall flag according to the motor operating current.

[0143] The second determination unit 400 is specifically configured to: detect whether the motor operating current is greater than a preset stall current threshold; if the motor operating current is greater than the preset stall current threshold, record the duration during which the motor operating current is greater than the preset stall current threshold; detect whether the duration is greater than a preset time; if the duration is greater than the preset time, set the current stall flag to a preset flag.

[0144] The third determination unit 500 is configured to determine that the motor is stalled when both the voltage stall flag and the current stall flag are preset flags, and control the motor to stop rotating.

[0145] In summary, by simultaneously monitoring the voltage value and the current value, when both the voltage stall flag and the current stall flag are triggered, it is possible to accurately identify whether the motor is stalled, so as to take timely measures to prevent the motor from being damaged.

[0146] Preferably, in combination with Figure 8 the content shown, the device further includes: a first acquisition unit, a judgment unit, and an execution unit.

[0147] The first acquisition unit is configured to acquire the position of the rearview mirror at the current moment.

[0148] The judgment unit is configured to judge whether the position of the rearview mirror at the current moment is at a specified position.

[0149] The execution unit is configured to, if the position of the rearview mirror at the current moment is not at the specified position, execute the step of acquiring the voltage value and the motor operating current at each moment of the rearview mirror.

[0150] Preferably, in combination with Figure 8 the content shown, the device further includes: a second acquisition unit, a stall unit, a calculation unit, and a fourth determination unit.

[0151] The second acquisition unit is configured to acquire the motor starting current and the motor rotating current.

[0152] The stall unit is configured to, when receiving a motor stall instruction, control the motor to stall according to the motor stall instruction to obtain a motor stall current.

[0153] A calculation unit for calculating the product between the motor starting current and the stall coefficient to obtain a stall current threshold value.

[0154] A fourth determination unit for, when the stall current threshold value is greater than the motor rotation current and less than the motor stall current, determining the stall current threshold value as a preset stall current threshold value.

[0155] In this specification, each embodiment is described in a progressive manner. What each embodiment focuses on explaining are the differences from other embodiments. For the same or similar parts among the embodiments, reference can be made to each other. What each embodiment focuses on explaining are the differences from other embodiments. In particular, for a system or a system embodiment, since it is basically similar to a method embodiment, the description is relatively simple. For the relevant parts, reference can be made to the partial description of the method embodiment. The systems and system embodiments described above are merely illustrative. The units described as separate components may or may not be physically separated. The components shown as units may or may not be physical units, that is, they may be located in one place or distributed to multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment. A person of ordinary skill in the art can understand and implement it without creative efforts.

[0156] Those skilled in the art can further realize that the units and algorithm steps of each example described in combination with the embodiments disclosed herein can be implemented by electronic hardware, computer software, or a combination of the two. To clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described according to functions in the above description. Whether these functions are executed in a hardware or software manner depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of the present invention.

[0157] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present application. Various modifications to these embodiments will be obvious to those skilled in the art. The general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for protecting a rearview mirror motor from stalling, characterized in that Including: When receiving a rearview mirror adjustment instruction, controlling a motor to rotate according to the rearview mirror adjustment instruction; During the rotation of the motor, obtaining the voltage value of the rearview mirror at each moment and the motor operating current; Determining a voltage stall flag according to the voltage value of the rearview mirror at each moment; Determining a current stall flag according to the motor operating current; When both the voltage stall flag and the current stall flag are preset flags, determining that the motor is stalled and controlling the motor to stop rotating.

2. The method according to claim 1, wherein Before obtaining the voltage value of the rearview mirror at each moment and the motor operating current, further including: Obtaining the position of the rearview mirror at the current moment; Judging whether the position of the rearview mirror at the current moment is at a specified position; If the position of the rearview mirror at the current moment is not at the specified position, performing the step of obtaining the voltage value of the rearview mirror at each moment and the motor operating current.

3. The method according to claim 1, wherein The determining the voltage stall flag according to the voltage value of the rearview mirror at each moment includes: For the voltage values of each adjacent moment, calculating the difference between the voltage values of the adjacent moments in the order of the acquisition time from early to late to obtain a voltage difference; Detecting whether the voltage difference is less than a preset voltage value within a preset time; If the voltage difference is less than the preset voltage value within the preset time, setting the voltage stall flag to a preset flag.

4. The method according to claim 1, wherein The determining the current stall flag according to the motor operating current includes: Detecting whether the motor operating current is greater than a preset stall current threshold; If the motor operating current is greater than the preset stall current threshold, recording the duration during which the motor operating current is greater than the preset stall current threshold; Detecting whether the duration is greater than a preset time; If the duration is greater than the preset time, setting the current stall flag to a preset flag.

5. The method according to claim 4, characterized in that Before detecting whether the motor operating current is greater than a preset stall current threshold, further including: Obtaining the motor starting current and the motor rotating current; When receiving a motor stall instruction, controlling the motor to stall according to the motor stall instruction to obtain a motor stall current; Calculating the product of the motor starting current and a stall coefficient to obtain a stall current threshold; When the stall current threshold is greater than the motor rotating current and the stall current threshold is less than the motor stall current, determining the stall current threshold as the preset stall current threshold.

6. A stall protection device for a rearview mirror motor, characterized in that, Including: A rotation unit, configured to control a motor to rotate according to the rearview mirror adjustment instruction when receiving the rearview mirror adjustment instruction; A data acquisition unit, configured to obtain the voltage value of the rearview mirror at each moment and the motor operating current during the rotation of the motor; A first determination unit, configured to determine a voltage stall flag according to the voltage value of the rearview mirror at each moment; A second determination unit, configured to determine a current stall flag according to the motor operating current; A third determination unit, configured to determine that the motor is stalled and control the motor to stop rotating when both the voltage stall flag and the current stall flag are preset flags.

7. The device according to claim 6, characterized in that, It further includes: A first acquisition unit, configured to acquire the position of the rearview mirror at the current moment; A judgment unit, configured to judge whether the position of the rearview mirror at the current moment is at a specified position; An execution unit, configured to, if the position of the rearview mirror at the current moment is not at the specified position, execute the step of acquiring the voltage value and the motor running current at each moment when the rearview mirror is located; 8. The device according to claim 6, wherein The first determination unit is specifically configured to: For the voltage values at each adjacent moment, calculate the difference between the voltage values at the adjacent moments in the order of the acquisition time from early to late to obtain a voltage difference; Detect whether the voltage difference is less than a preset voltage value within a preset time; If the voltage difference is less than the preset voltage value within the preset time, set a voltage locked-rotor flag to a preset flag; 9. The device according to claim 6, characterized in that, The second determination unit is specifically configured to: Detect whether the motor running current is greater than a preset locked-rotor current threshold; If the motor running current is greater than the preset locked-rotor current threshold, record the duration during which the motor running current is greater than the preset locked-rotor current threshold; Detect whether the duration is greater than a preset time; If the duration is greater than the preset time, set a current locked-rotor flag to a preset flag; 10. The device according to claim 9, characterized in that, It further includes: A second acquisition unit, configured to acquire a motor starting current and a motor rotating current; A locked-rotor unit, configured to, after receiving a motor locked-rotor instruction, control the motor to be locked-rotor according to the motor locked-rotor instruction to acquire a motor locked-rotor current; A calculation unit, configured to calculate the product of the motor starting current and a locked-rotor coefficient to obtain a locked-rotor current threshold; A fourth determination unit, configured to, when the locked-rotor current threshold is greater than the motor rotating current and the locked-rotor current threshold is less than the motor locked-rotor current, determine the locked-rotor current threshold as the preset locked-rotor current threshold.

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