A control method, a control device and a vehicle refrigeration device

Abstract

The embodiment of the present application discloses a control method, a control device and a vehicle refrigerating device, which are used for controlling initialization of an electronic expansion valve, the electronic expansion valve comprising a stepping motor, a Hall sensor is arranged close to the stepping motor, the stepping motor is used for operating at a specific rotating speed, and the Hall sensor is used for sensing magnetic field change caused by rotation of the stepping motor to generate a corresponding Hall signal; the control method comprises: an initialization stage, controlling the stepping motor to operate at an i-th rotating speed, and detecting an i-th Hall signal generated by the Hall sensor to determine whether the stepping motor is end-striking; if it is determined that the stepping motor is not end-striking, controlling the stepping motor to operate at an i+1-th rotating speed, and detecting an i+1-th Hall signal generated by the Hall sensor to determine whether the stepping motor is end-striking; and if it is determined that the stepping motor is end-striking, controlling the initialization to be completed. In the embodiment of the present application, the phenomenon that the end-striking is not detected and the end-striking is continuously caused is avoided.

Description

Technical Field

[0001] This invention relates to a control method, a control device, and a vehicle refrigeration device. Background Technology

[0002] An electric valve, consisting of a stepper motor, valve body, controller, etc., is mainly used to regulate the refrigerant flow in an air conditioning system.

[0003] The electric valve requires initialization for zero-point calibration each time it is powered on. During initialization, the electric valve typically moves towards the fully closed position and completes a certain number of steps to ensure it is in the fully closed position. A limit switch is installed in the fully closed position of the electric valve. During initialization, the valve impacts the limit switch, restricting the movement of the valve core and ensuring the electric valve is in the fully closed position, thus completing the initialization process.

[0004] If the endpoints are constantly being hit during initialization, it will be detrimental to product wear and system noise. Therefore, it is necessary to identify the hitting endpoints to minimize the impact on the endpoints during initialization.

[0005] However, existing collision detection methods suffer from false detections, which can lead to continuous collisions during the initialization phase. Summary of the Invention

[0006] This invention provides a control method, a control device, and an automotive refrigeration device to solve the problem of false detection in existing collision detection methods.

[0007] This invention provides a control method for initializing an electronic expansion valve. The electronic expansion valve includes a stepper motor and a Hall sensor disposed near the stepper motor. The stepper motor is used to operate at a specific speed, and the Hall sensor is used to sense the magnetic field changes caused by the rotation of the stepper motor to generate a corresponding Hall signal.

[0008] The control method includes:

[0009] During the initialization phase, the stepper motor is controlled to run at the i-th speed, and the i-th Hall signal generated by the Hall sensor is detected to determine whether the stepper motor has collided with the end.

[0010] If it is determined that the stepper motor has not collided with the end, the stepper motor is controlled to run at the (i+1)th speed, and the (i+1)th Hall signal generated by the Hall sensor is detected to determine whether the stepper motor has collided with the end.

[0011] If the stepper motor is determined to be in a collision state, the control initialization is complete, i = 1, 2, ...

[0012] Based on the same inventive concept, this embodiment of the invention also provides a control device for controlling an electronic expansion valve, the control device including a main control module;

[0013] The electronic expansion valve includes a stepper motor and a Hall sensor disposed near the stepper motor. The stepper motor is used to operate at a specific speed, and the Hall sensor is used to sense the magnetic field change caused by the rotation of the stepper motor to generate a corresponding Hall signal.

[0014] The main control module is used to control the stepper motor to run at the i-th speed during the initialization phase of the electronic expansion valve, and to detect the i-th Hall signal generated by the Hall sensor to determine whether the stepper motor has collided with the end; if it is determined that the stepper motor has not collided with the end, the main control module controls the stepper motor to run at the (i+1)-th speed, and detects the (i+1)-th Hall signal generated by the Hall sensor to determine whether the stepper motor has collided with the end; if it is determined that the stepper motor has collided with the end, the initialization is completed, i = 1, 2, ...

[0015] Based on the same inventive concept, embodiments of the present invention also provide a vehicle refrigeration device, including: the control device as described above.

[0016] In this embodiment of the invention, the control method, control device, and automotive refrigeration device, upon determining that the stepper motor has not collided at the current speed, control the stepper motor to switch speeds. They then determine whether a collision has occurred based on Hall signals at different speeds, avoiding the problem of the stepper motor being unable to detect a collision during the initialization phase when it is in the resonant speed range. This solves the problem of false detection during motor resonance and improves detection accuracy. If a collision is detected at the current speed, initialization is completed, ending the initialization phase of the electronic expansion valve. This achieves effective identification of collisions, allowing for timely control to stop collisions immediately upon detection, reducing continuous collisions, thereby reducing wear on the electronic expansion valve, decreasing noise during initialization, and reducing the initialization time. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, although the drawings described below are some specific embodiments of the present invention, those skilled in the art can extend and extend the basic concepts of the device structure, driving method and manufacturing method disclosed and indicated by various embodiments of the present invention to other structures and drawings. Undoubtedly, these should all be within the scope of the claims of the present invention.

[0018] Figure 1 This is a schematic diagram of the motor rotor and Hall sensor provided in an embodiment of the present invention;

[0019] Figure 2 This is a waveform diagram of the Hall signal from the Hall sensor under constant speed of a stepper motor;

[0020] Figure 3 This is a waveform diagram of the Hall signal from the Hall sensor at different speeds of the stepper motor;

[0021] Figure 4 This is a schematic diagram of a control method provided in an embodiment of the present invention;

[0022] Figure 5 This is the Hall signal waveform corresponding to the rebound impact point;

[0023] Figure 6 This is the Hall signal waveform corresponding to the jammed impact end;

[0024] Figure 7 yes Figure 4 Flowchart of step S10;

[0025] Figure 8 yes Figure 4 Another flowchart for step S10;

[0026] Figure 9 yes Figure 4 Another flowchart for step S10;

[0027] Figure 10 This is a schematic diagram of a control method provided in an embodiment of the present invention. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of this invention. Obviously, the described embodiments are only some embodiments of this invention, not all embodiments. Based on the basic concepts disclosed and indicated in the embodiments of this invention, all other embodiments obtained by those skilled in the art are within the scope of protection of this invention.

[0029] The electronic expansion valve can be any type of electrically operated electronic expansion valve. The electronic expansion valve includes a stepper motor and a Hall sensor located near the stepper motor. The stepper motor is used to operate at a specific speed, and the Hall sensor is used to sense the magnetic field changes caused by the rotation of the stepper motor to generate a corresponding Hall signal.

[0030] Electronic expansion valves are commonly used in air conditioning systems to regulate refrigerant flow. They utilize electrical signals generated by the regulated parameters to control the voltage or current applied to the valve, thereby regulating the refrigerant supply. Electric electronic expansion valves rely on a stepper motor to drive the valve body, causing it to move and thus regulating the flow rate. Before regulating flow, the valve body should be in the fully closed position. Therefore, the electronic expansion valve needs to be initialized to the fully closed position each time it is powered on. After initialization, the electronic expansion valve begins operation. It can be understood that "powering on" refers to powering on the device used by the electronic expansion valve. For example, if the electronic expansion valve is for automotive applications, it needs to be initialized every time the car is powered on.

[0031] The optional stepper motor includes a motor rotor and a Hall sensor positioned close to the motor rotor. The stepper motor is used to operate at a specific speed to make the motor rotor rotate at a specific speed. The Hall sensor is used to sense changes in the magnetic field of the motor rotor to generate a corresponding Hall signal. By detecting the Hall signal, it can be determined whether the stepper motor has collided with a terminal.

[0032] Alternatively, a stepper motor may include a valve stem, and a Hall sensor may be positioned close to the valve stem. The stepper motor is used to operate at a specific speed to rotate the valve stem at a specific speed. The Hall sensor is used to sense changes in the magnetic field of the valve stem to generate a corresponding Hall signal. The stepper motor may be hit by detecting the Hall signal.

[0033] The following description uses the example of a Hall sensor generating a Hall signal by sensing changes in the magnetic field of a motor rotor. The principle and process of a Hall sensor generating a Hall signal by sensing changes in the magnetic field of a valve body are the same and will not be elaborated further.

[0034] like Figure 1 As shown, the motor rotor 101 includes at least one pair of magnetic poles, each pair consisting of an N pole and a S pole. The N poles and S poles in the motor rotor 101 are arranged adjacent to each other, while the N poles of multiple pairs of magnetic poles are arranged at intervals. A Hall sensor 102 is positioned close to the motor rotor 101. The Hall sensor 102 can sense the magnetic poles that are close to it and generate a corresponding feedback signal, i.e., a Hall signal. When the stepper motor runs at a speed v1, the motor rotor 101 in the stepper motor rotates at a speed v1, and the magnetic poles of the motor rotor corresponding to the Hall sensor 102 change alternately. Each change in the magnetic poles of the motor rotor 101 after passing through the Hall sensor 102 causes a level jump in the feedback signal generated by the Hall sensor 102. It can be understood that a feedback signal is the signal corresponding to the fixed magnetic poles of the motor rotor 101 after passing through the Hall sensor 102. The continuous feedback signals generated by the Hall sensor 102 constitute the Hall signal.

[0035] For example, when the motor rotor magnetic pole corresponding to Hall sensor 102 is the N pole, Hall sensor 102 generates a low-level feedback signal L; when the motor rotor magnetic pole corresponding to Hall sensor 102 is the S pole, Hall sensor 102 generates a high-level feedback signal H. Therefore, when the motor rotor magnetic pole corresponding to Hall sensor 102 jumps from the N pole to the S pole, the feedback signal generated by Hall sensor 102 jumps from L to H. The duration of the Hall signal operation is the duration for which the Hall sensor holds a signal, which can be either a low-level duration or a high-level duration. Figure 1 The optional motor rotor 101 rotates clockwise. As the motor rotor 101 rotates clockwise, the motor rotor magnetic poles corresponding to the Hall sensor 102 alternate in the order N, S, N, S, N, S. Figure 2 The feedback signal generated by the Hall sensor 102 shown jumps in the order of L, H, L, H, L, H. Therefore, the waveform of the Hall signal generated by the Hall sensor 102 is a square wave. The period of this square wave is related to the speed and state of the motor rotor 101. Different operating states of the stepper motor will result in different periods and durations of the Hall signal output by the Hall sensor 102.

[0036] For the same stepper motor, under normal operating conditions, the period length of the Hall signal generated by the Hall sensor is related to the stepper motor's operating speed. Changes in the stepper motor's speed alter the switching speed of the motor's rotor magnetic field through the Hall sensor, thus changing the Hall signal period length. Specifically, the Hall signal period length is inversely proportional to the stepper motor's speed. The higher the stepper motor speed, the faster the switching speed of the motor's rotor magnetic field through the Hall sensor, resulting in a shorter Hall signal period; conversely, the lower the stepper motor speed, the slower the switching speed of the motor's rotor magnetic field through the Hall sensor, resulting in a longer Hall signal period. However, when the stepper motor maintains a constant speed, the Hall signal period length remains consistent. Figure 3 As shown, as the stepper motor speed increases from 400 RPM to 600 RPM, the Hall signal period length decreases as the stepper motor speed increases, where Ta > Tb > Tc.

[0037] Each time the device is powered on, the integrated electronic expansion valve needs to be initialized to be in the fully closed position. When the valve body of the electronic expansion valve impacts the limit frame, it can ensure that the electronic expansion valve is in the fully closed position. Therefore, the electronic expansion valve will use the impact end to reach the fully closed position during the initialization phase.

[0038] The initialization stroke of an electronic expansion valve is relatively large. If the valve continuously impacts its endpoint during initialization, it will negatively impact valve wear and increase noise in the air conditioning system. Therefore, it is necessary to identify and address the impact phenomenon in the electronic expansion valve, ending the initialization process upon detection of an impact to prevent continuous impact. In actual products, electronic expansion valve impacts can manifest as either rebound impacts or jamming impacts. When a jamming impact occurs, the motor does not run, and the Hall signal remains in its previous state without any change; this is considered a jamming impact. When a rebound impact occurs, the Hall signal transition period is uncertain, potentially exhibiting irregular or unpredictable transitions; this is also considered a rebound impact.

[0039] However, current air conditioning systems exhibit false detections in cases of electronic expansion valve collisions. For example, the motor speed has a resonant speed range; when the motor operates within this range, it resonates. In this case, the Hall signal period during a collision is the same as the period during normal motor operation, making it impossible to identify the collision and leading to a false detection. Furthermore, when a rebound collision occurs, the Hall signal period can be regular or irregular. If it is irregular, the initialization detection device can effectively identify the collision; if it is regular, the initialization device cannot identify the collision, resulting in a false detection. False detections can cause the electronic expansion valve to continuously collide during the initialization phase until the initialization process is complete, severely impacting the valve's lifespan, wear, and initialization efficiency.

[0040] Based on this, embodiments of the present invention provide a control method for controlling the initialization of an electronic expansion valve, which can effectively avoid false detections due to collision. (Reference) Figure 4 The diagram shown is a schematic of a control method provided in an embodiment of the present invention. The control method can be executed by a control device, which can be implemented in software and / or hardware and configured in the device on which the electronic expansion valve is applied. For example, the control device of an automotive air conditioning system can be integrated into the vehicle controller or the controller of the air conditioning system, and is not limited thereto.

[0041] like Figure 4 The control method shown includes:

[0042] S10. During the initialization phase, the stepper motor is controlled to run at the i-th speed, and the i-th Hall signal generated by the Hall sensor is detected to determine whether the stepper motor has collided with the terminal.

[0043] S20. If it is determined that the stepper motor has not collided with the end, control the stepper motor to run at the (i+1)th speed, and detect the (i+1)th Hall signal generated by the Hall sensor to determine whether the stepper motor has collided with the end.

[0044] S30. If the stepper motor is determined to be in contact with the terminal, the control initialization is completed, i = 1, 2, ...

[0045] In this embodiment, during the initialization phase, the control device controls the stepper motor to run at a first speed V1. The motor rotor rotates at this first speed V1, and the Hall sensor detects the change in the magnetic field of the motor rotor to generate a first Hall signal. The control device detects this first Hall signal and determines whether the stepper motor has experienced a collision. If a collision is determined, the control initialization is complete.

[0046] If it is determined that the stepper motor has not collided with a terminal, the control device switches the stepper motor from the first speed V1 to the second speed V2. The motor rotor rotates at this second speed V2, and the Hall sensor detects the change in the magnetic field of the motor rotor to generate a second Hall signal. The control device detects this second Hall signal and determines whether the stepper motor has collided with a terminal based on it. If a collision is determined, the control initialization is complete.

[0047] If it is determined that the stepper motor has not collided with a terminal, the control device switches the stepper motor from the second speed V2 to the third speed V3. The motor rotor rotates at this third speed V3, and the Hall sensor detects the change in the magnetic field of the motor rotor to generate a third Hall signal. The control device detects this third Hall signal and determines whether the stepper motor has collided with a terminal based on it.

[0048] Similarly, if the control device determines that the stepper motor is colliding at the current speed, it will complete the initialization process, ending the initialization phase of the electronic expansion valve. Effective collision detection and immediate stopping after a collision effectively reduce wear and noise of the electronic expansion valve and shorten the initialization time. If it determines that the stepper motor is not colliding at the current speed, it will control the stepper motor to switch speeds, using Hall effect signals at different speeds to determine if a collision has occurred. It's understandable that the speed after the stepper motor switches will be different from any speed before the switch.

[0049] In this embodiment, during the initialization phase, if no collision is detected, the motor speed is changed and Hall signal detection is performed again. This allows the motor speed to be adjusted to a non-resonant speed range, preventing the motor from resonating. Therefore, collisions can be identified based on the Hall signal, avoiding false detections and solving the problem of continuous collisions during the initialization phase caused by false detections.

[0050] The principle for determining the impact of an electronic expansion valve is as follows. During normal operation of a stepper motor, every two full steps, the magnetic poles of the motor rotor change, and the corresponding feedback signal generated by the Hall sensor will experience a jump. (Refer to...) Figure 2The image shows the Hall signal output waveform of a stepper motor running at a constant speed. This output waveform can be acquired using an oscilloscope. In the waveform graph, the horizontal axis represents time, and the vertical axis represents voltage value. If a full step of the stepper motor uses a control scheme of X microsteps, then under normal operating conditions, the theoretical duration of a feedback signal is 2 full step times, or 2X microstep times. 2X microstep times equals T. th That is, T th Let T be the theoretical duration of the feedback signal. If the actual duration of a feedback signal is T... re Not equal to T th If an abnormal Hall signal is detected, the stepper motor is considered to be in an abnormal operating state, i.e., an abnormal situation such as a collision has occurred. Therefore, in the initialization detection, the appearance of an abnormal Hall signal can be considered as the electronic expansion valve colliding with an end point.

[0051] The impact points of an electronic expansion valve can be divided into rebound impact points and jamming impact points. When a rebound impact occurs, the motor rotor, via the Hall sensor, jumps between the two magnetic poles, and the stepper motor does not completely stop. The jamming impact occurs when the stepper motor is not running; the motor rotor, via the Hall sensor, is fixed to the same magnetic pole, causing the Hall signal to remain in its previous state without any jump. Based on this, it can be known that... Figure 5 As shown, when the electronic expansion valve rebounds and hits the end, the Hall signal switching period generated by the Hall sensor becomes irregular, and the duration of one or more feedback signals generated by the Hall sensor differs from Tth; for example... Figure 6 As shown, when the electronic expansion valve jams at the end, one or more feedback signals generated by the Hall sensor do not change for a long time, that is, the continuous running time of the feedback signal is much longer than Tth.

[0052] Thus, a collision is identified based on the Hall signal. It should be noted that, under normal circumstances, the Hall signal period in a collision situation is clearly distinguishable from the Hall signal period in normal operation. However, each stepper motor has a resonant speed range, and these resonant speed ranges may differ between different stepper motors. When the stepper motor's speed is within its corresponding resonant speed range, the stepper motor will resonate. At this time, the Hall signal period sensed by the Hall sensor under normal operation is the same as the Hall signal period in a collision situation. Therefore, a collision occurring at this speed cannot be determined from the Hall signal alone, potentially leading to the complete completion of the stroke during the initialization phase, resulting in a time-consuming defect.

[0053] If no collision is detected, there may be a false detection due to motor resonance. In this embodiment, the motor speed can be changed before Hall signal detection. Until the initialization phase, the motor speed is adjusted to the non-resonant speed range, and the motor will not resonate. Then, the collision can be identified based on the Hall signal, avoiding the problem of false detection and solving the problem of continuous collisions during the initialization phase caused by false detection.

[0054] like Figure 7 The optional step S10, which involves detecting the i-th Hall signal generated by the Hall sensor to determine whether the stepper motor has collided with the terminal, includes: Step S11, calculating the running duration of the i-th Hall signal and detecting whether the running duration is within the theoretical running range corresponding to the i-th rotational speed; Step S12, if yes, determining that the stepper motor has not collided with the terminal; Step S13, if no, determining that the stepper motor has collided with the terminal. When the control device determines the collision situation of the stepper motor, it can use the actual running duration T of the feedback signal. re Its corresponding theoretical running duration T th By comparison, it is understandable that T rei T represents the actual operating duration of the i-th Hall signal. thi This represents the theoretical operating duration corresponding to the i-th rotational speed.

[0055] For the i-th Hall signal, T rei Exceeding T thi When the error range is within the theoretical operating range, a collision is determined, and the initialization phase can be terminated. Conversely, when T... rei Falling into T thi If the error is within the specified range, it is determined that no collision has occurred. This may be because no collision has actually occurred, or it may be due to motor resonance causing the inability to identify the collision and resulting in a false detection. In this case, the stepper motor speed is adjusted and the detection is repeated until a collision is determined to have occurred, thus avoiding false detections caused by motor resonance. Figure 7 The control method shown is applicable to both bounce-off and jamming impact detection.

[0056] In this embodiment, during the initialization phase, if no collision is detected, the control device will control the stepper motor speed adjustment until a collision is determined. This speed adjustment can avoid the problem of the stepper motor being in the resonant speed range during the initialization phase, thus solving the false detection phenomenon and improving the detection accuracy.

[0057] Optional steps for determining that the stepper motor has not collided with a terminal include: switching the stepper motor speed according to a fixed switching cycle, where the fixed switching cycle is a fixed time length or a fixed number of steps. When the control device determines that the stepper motor has not collided with a terminal at the current speed, it controls the stepper motor to switch speeds. This switching rule uses a fixed time length or a fixed number of steps as the switching cycle. For example, the control device controls the stepper motor to run for a fixed time length at each speed, such as 5 seconds. After running for 5 seconds at the first speed, if a collision is not detected, it directly switches to the second speed. If a collision is detected after running for 2 seconds at the second speed, the initialization phase ends. Alternatively, the control device controls the stepper motor to run for a fixed number of steps at each speed, such as 48 full steps. After running 48 full steps at the first speed, if a collision is not detected, it directly switches to the second speed. If a collision is detected after running 16 full steps, the initialization phase ends.

[0058] In this embodiment of the invention, when the control device determines that the stepper motor has not collided at the current speed, it controls the stepper motor to switch speeds. It then uses Hall signals at different speeds to determine whether a collision has occurred. This avoids the problem of the stepper motor being unable to detect a collision during the initialization phase when it is in the resonant speed range, thus solving the false detection problem and improving detection accuracy. If the stepper motor is determined to have collided at the current speed, the control device completes the initialization process, ending the initialization phase of the electronic expansion valve. This achieves effective identification of collisions, allowing for timely control to stop the collision immediately upon detection, reducing continuous collisions, thereby reducing wear on the electronic expansion valve, decreasing noise during the initialization process, and reducing the initialization time.

[0059] For example, based on the above technical solutions, such as Figure 8 The optional step S10 shown, which detects the i-th Hall signal generated by the Hall sensor to determine whether the stepper motor has collided with the end, further includes the following steps:

[0060] Step S14: Calculate the running duration of the i-th Hall signal and check whether the running duration is greater than Tthi*M;

[0061] Step S15: If not, determine that the stepper motor has not collided with the end;

[0062] Step S16: If yes, determine the stepper motor collision; where Tthi is the theoretical running duration corresponding to the i-th speed, and M is greater than or equal to 4.

[0063] During normal operation of a stepper motor, the Hall signal period corresponding to a given speed is fixed, with a duty cycle of 50%, meaning that high and low levels each account for approximately 50% of the period. However, when a collision occurs, the Hall signal transitions become irregular. Especially in the case of a jammed collision, the Hall signal period may not transition for a considerable period, meaning the duty cycle may be significantly lower or higher than 50%. Let Tthi be the theoretical operating duration corresponding to the i-th speed, which is two full steps. Based on this, the actual operating duration T of the i-th Hall signal is calculated. rei And detect the duration T of the run. rei Does it exceed 8 full steps? If it does, it means the Hall signal did not change within 8 full steps, possibly indicating a stuck terminal; if it is less than 8 full steps, it means the Hall signal changed within 8 full steps, and it is not a stuck terminal. Therefore Figure 8 The control method shown is suitable for jamming and impact detection, reduces continuous impact during the initialization phase, can reduce wear on the electronic expansion valve, reduce noise during the initialization process, and reduce the time consumed during the initialization phase.

[0064] For example, based on the above technical solution, the control method may optionally further include, before entering the initialization stage: establishing a weight database; setting multiple specific operating intervals corresponding to the i-th rotational speed, and setting the weight value corresponding to the multiple specific operating intervals as Ni, where Ni < 0 when the specific operating interval is a theoretical operating interval, and Ni > 0 when the specific operating interval is a non-theoretical operating interval, and the weight value matched by a specific operating interval far from the theoretical operating interval is greater than the weight value matched by a specific operating interval close to the theoretical operating interval. The theoretical operating interval may be [(1-ΔT1)Tthi, (1+ΔT1)Tthi], 0 ≤ ΔT1 ≤ 0.5, where Tthi is the theoretical operating duration corresponding to the i-th rotational speed, and the weight value matched by this theoretical operating interval is set as N0, -1 ≤ N0 ≤ 0.

[0065] In this embodiment, a weight is also set for the actual operating duration Trei relative to the theoretical operating range. Specifically, outside the theoretical operating range, the larger the difference between Trei and Trei, the larger the weight value set for the specific operating range in which the actual operating duration falls. All weights are greater than 0, further improving detection accuracy. The actual operating duration Trei can be understood as the actual operating duration corresponding to the i-th rotational speed. Clearly, Tre1 can be understood as the actual operating duration corresponding to the 1st rotational speed, Tre2 as the actual operating duration corresponding to the 2nd rotational speed, and so on.

[0066] In this embodiment, the i-th rotational speed corresponds to multiple specific operating ranges, for example, five specific operating ranges. The weight values ​​corresponding to these five specific operating ranges are labeled as N1 to N5, respectively. It can be understood that the i-th rotational speed also corresponds to a theoretical operating range, and the theoretical operating ranges corresponding to different rotational speeds may be different.

[0067] For the i-th speed, when a specific operating range does not exceed its theoretical operating range, the weight value Ni corresponding to that specific operating range is < 0; when a specific operating range is outside the theoretical operating range, the weight value Ni corresponding to that specific operating range is > 0. Furthermore, the weight value matched for a specific operating range far from the theoretical operating range is greater than the weight value matched for a specific operating range close to the theoretical operating range. For example, for the i-th speed, when its specific operating range N1 does not exceed its theoretical operating range, N1 is set to < 0; when its specific operating range N3 is outside the theoretical operating range, N3 is set to > 0; for any two specific operating ranges, such as N1 and N4, if N4 is further away from the theoretical operating range than N1, then N4 is set to be greater than N1.

[0068] Optional settings for multiple specific operating ranges corresponding to the i-th speed include: setting a first specific operating range corresponding to the i-th speed, and setting the weight value matched by the first specific operating range to N1, wherein the first specific operating range is (-∞, (1-ΔT1)Tthi) or ((1+ΔT1)Tthi, 2Tthi]; setting a second specific operating range corresponding to the i-th speed, and setting the weight value matched by the second specific operating range to N2, wherein the second specific operating range is (2Tthi, 3Tthi]; setting a third specific operating range corresponding to the i-th speed, and setting the weight value matched by the third specific operating range to N3, wherein the third specific operating range is (3Tthi, +∞); wherein, 1 <N1<N2<N3。

[0069] like Figure 9 The operation of detecting the i-th Hall signal generated by the Hall sensor in step S10 to determine whether the stepper motor has collided with the end also includes the following steps:

[0070] Step S17: Calculate the running duration of the i-th Hall signal and determine the target specific running interval to which the running duration belongs;

[0071] Step S18: Find the target weight value corresponding to the specific running interval of the target, and accumulate them to obtain the current total weight;

[0072] Step S191: If the total weight is less than the preset total weight, it is determined that the stepper motor has not collided with the end; S192: If the total weight is greater than or equal to the preset total weight, it is determined that the stepper motor has collided with the end, wherein the preset total weight ST≥N2+N3.

[0073] The respective weight values corresponding to the optional i-th rotational speed are N0 = -1, N1 = +2, N2 = +4, N3 = +6, ST = 10, and ΔT1 = 0.3. It can be understood that the ranges of the theoretical operating interval and the matching weight value N0, the range of the first specific operating interval and the matching weight value N1, the range of the second specific operating interval and the matching weight value N2, the range of the third specific operating interval and the matching weight value N3, and the numerical values of the above parameters are only specific examples. The weight databases of different electronic expansion valves may be different and are not limited to this.

[0074] As described above, the flow of this control method is as Figure 10 shown

[0075] S201. The device is powered on and the initialization process starts;

[0076] S202. The control device obtains an initialization command based on the power-on situation of the device;

[0077] S203. The stepping motor operates at the 1st rotational speed, i.e., i = 1. The control device obtains the 1st Hall signal thereby and detects whether the 1st Hall signal jumps. If yes, execute step S204; if no, execute step S213;

[0078] S204. Detect whether the actual operating duration Tre1 of the 1st Hall signal is within the theoretical operating interval 0.7Tth1 ≤ Tre1 ≤ 1.3Tth1 corresponding to the 1st rotational speed. If no, execute step S205; if yes, execute step S208;

[0079] S205. Detect whether Tre1 is within the first specific operating interval Tre1 < 0.7Tth1 or 1.3Tth1 < Tre1 ≤ 2Tth1 corresponding to the 1st rotational speed. If no, execute step S206; if yes, execute step S209;

[0080] S206. Detect whether Tre1 is within the second specific operating interval 2Tth1 < Tre1 ≤ 3Tth1 corresponding to the 1st rotational speed. If no, execute step S207; if yes, execute step S210;

[0081] S207. Determine that Tre1 is within the third specific operating interval 3Tth1 < Tre1 corresponding to the 1st rotational speed and execute step S211;

[0082] S208. Determine that the weight value of the 1st Hall signal is -1, then accumulate it to the current total weight count and jump to step S212;

[0083] S209. If the weight value of the first Hall signal is determined to be +2, then it is added to the current total weight count, and the process jumps to step S212.

[0084] S210. Determine the weight value of the first Hall signal as +4, then add it to the current total weight count, and jump to step S212.

[0085] S211. Determine that the weight value of the first Hall signal is +6, then add it to the current total weight count, and jump to step S212;

[0086] S212. Calculate the total weight values ​​from the first rotation speed to the current rotation speed and determine whether the total count is greater than 10. If not, return to step S203 and i = i + 1. If yes, execute step S214.

[0087] S213. Check if Tre1 exceeds the 8 full steps corresponding to the first rotation speed. If not, return to step S203 and i = i + 1. If yes, execute step S214.

[0088] S214, Determine the collision point;

[0089] S215, Control initialization complete.

[0090] As mentioned above, STALL_COUNT represents the total weight. During the initialization phase, the stepper motor is powered on and adjusted to speed 1, at which point the base weight is 0. When the stepper motor switches from speed 1 to speed 2, the base weight becomes the sum of the weight values ​​obtained before speed 2. If the Hall signal period is within the normal threshold range, STALL_COUNT is decremented by 1. If it is not within the normal threshold range, the increment of STALL_COUNT is determined based on the actual value range. This continues until STALL_COUNT accumulates to more than 10, at which point a collision is identified. Of course, the preset total weight of 10 can be updated according to actual requirements.

[0091] The collision detection algorithm described above determines the weight value based on the duration of the Hall signal period. If the total weight value accumulates beyond the preset weight after switching multiple rotation speeds, it indicates an abnormal Hall signal and is identified as a collision / stall. Alternatively, if the Hall period Treal > 8 full steps, it is also directly identified as a stall. This algorithm improves detection accuracy and avoids false detections.

[0092] The control method provided in this embodiment performs speed adjustment during the initialization phase. At different motor speeds, the Hall signal of the Hall sensor is used to detect collisions and identify whether a collision has occurred. If a collision is detected, the initialization phase can be stopped in time to eliminate the possibility of false detections and avoid the phenomenon of continuous collisions due to failure to detect collisions. This can reduce continuous collisions during initialization, reduce wear caused by continuous collisions, reduce initialization time, and reduce noise during the initialization process.

[0093] Based on the same inventive concept, embodiments of the present invention also provide a control device for controlling an electronic expansion valve, which is used to execute the control method described in any of the above embodiments. The control device includes a main control module; the electronic expansion valve includes a stepper motor, a Hall sensor is disposed near the stepper motor, the stepper motor is used to operate at a specific speed, and the Hall sensor is used to sense the magnetic field change caused by the rotation of the stepper motor to generate a corresponding Hall signal;

[0094] The main control module is used during the initialization phase of the electronic expansion valve to control the stepper motor to run at the i-th speed and detect the i-th Hall signal generated by the Hall sensor to determine whether the stepper motor has collided with the terminal. If it is determined that the stepper motor has not collided with the terminal, the main control module controls the stepper motor to run at the (i+1)-th speed and detects the (i+1)-th Hall signal generated by the Hall sensor to determine whether the stepper motor has collided with the terminal. If it is determined that the stepper motor has collided with the terminal, the control initialization is completed, i = 1, 2, ...

[0095] Optionally, when the main control module determines that the stepper motor has not collided with the end, it switches the speed of the stepper motor according to a fixed switching cycle, which is a fixed time length or a fixed number of steps.

[0096] The optional main control module includes: a calculation unit, used to calculate the running duration of the i-th Hall signal and detect whether the running duration is within the theoretical running range corresponding to the i-th speed; and a judgment unit, used to determine that the stepper motor has not collided if the running duration is within the theoretical running range corresponding to the i-th speed; otherwise, to determine that the stepper motor has collided.

[0097] The optional main control module includes: a calculation unit, used to calculate the running duration of the i-th Hall signal and detect whether the running duration is greater than Tthi*M; and a judgment unit, used to determine that the stepper motor has not collided if the running duration is less than or equal to Tthi*M; otherwise, to determine that the stepper motor has collided. Wherein, Tthi is the theoretical running duration corresponding to the i-th speed, and M is greater than or equal to 4.

[0098] Optionally, the control device may further include: a database preset module, used to establish a weight database before entering the initialization phase, wherein the i-th rotational speed is set to correspond to multiple specific operating ranges, and the weight value corresponding to the multiple specific operating ranges is set to Ni. When the specific operating range is the theoretical operating range, Ni < 0; when the specific operating range is a non-theoretical operating range, Ni > 0; and the weight value matched by a specific operating range far from the theoretical operating range is greater than the weight value matched by a specific operating range close to the theoretical operating range.

[0099] The selectable theoretical operating range is [(1-ΔT1)Tthi, (1+ΔT1)Tthi], 0≤ΔT1≤0.5, where Tthi is the theoretical operating duration corresponding to the i-th rotational speed. The weight value matched by this theoretical operating range is set to N0, -1≤N0≤0.

[0100] Optional settings for the i-th rotational speed corresponding to multiple specific operating ranges include:

[0101] Define a first specific operating range corresponding to the i-th rotational speed and set the weight value matched by the first specific operating range to N1. The first specific operating range is (-∞, (1-ΔT1)Tthi) or ((1+ΔT1)Tthi, 2Tthi]; define a second specific operating range corresponding to the i-th rotational speed and set the weight value matched by the second specific operating range to N2. The second specific operating range is (2Tthi, 3Tthi]; define a third specific operating range corresponding to the i-th rotational speed and set the weight value matched by the third specific operating range to N3. The third specific operating range is (3Tthi, +∞); where 1 <N1<N2<N3。

[0102] The optional main control module includes: a calculation unit, used to calculate the running duration of the i-th Hall signal, determine the target specific running interval to which the running duration belongs, find the target weight value corresponding to the target specific running interval, and accumulate them to obtain the current total weight; and a judgment unit, used to determine that the stepper motor has not collided if the total weight is less than the preset total weight, otherwise, determine that the stepper motor has collided, wherein the preset total weight ST≥N2+N3.

[0103] The control device provided in this embodiment performs speed adjustment during the initialization phase. At different motor speeds, it uses the Hall signal of the Hall sensor to perform collision detection to identify whether a collision has occurred. After a collision is detected, the initialization phase is stopped in time to eliminate the possibility of false detection and avoid the phenomenon of continuous collisions due to failure to detect collisions. This can reduce continuous collisions during initialization, reduce wear caused by continuous collisions, reduce initialization time, and reduce noise during the initialization process.

[0104] Based on the same inventive concept, embodiments of the present invention also provide a vehicle refrigeration device, including: the control device as described in any of the above embodiments.

[0105] Note that the above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments, combinations, and substitutions can be made without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of the present invention, the scope of which is determined by the scope of the appended claims.

Claims

1. A control method for controlling the initialization of an electronic expansion valve, characterized in that, The electronic expansion valve includes a stepper motor and a Hall sensor disposed near the stepper motor. The stepper motor is used to operate at a specific speed, and the Hall sensor is used to sense the magnetic field change caused by the rotation of the stepper motor to generate a corresponding Hall signal. The control method includes: During the initialization phase, the stepper motor is controlled to run at the i-th speed, and the i-th Hall signal generated by the Hall sensor is detected to determine whether the stepper motor has collided with the end. If it is determined that the stepper motor has not collided with the end, the stepper motor is controlled to run at the (i+1)th speed, and the (i+1)th Hall signal generated by the Hall sensor is detected to determine whether the stepper motor has collided with the end. If the stepper motor is determined to be in a collision state, the control initialization is complete, i = 1, 2, ...

2. The control method according to claim 1, characterized in that, When determining that the stepper motor has not collided with the end, the method further includes: The stepper motor speed is switched according to a fixed switching cycle, which is a fixed time length or a fixed number of steps.

3. The control method according to claim 1, characterized in that, Detecting the i-th Hall signal generated by the Hall sensor to determine whether the stepper motor has collided with the terminal includes: Calculate the running duration of the i-th Hall signal and detect whether the running duration is within the theoretical running range corresponding to the i-th rotational speed; If yes, determine that the stepper motor has not collided with the end; if no, determine that the stepper motor has collided with the end.

4. The control method according to claim 1, characterized in that, Detecting the i-th Hall signal generated by the Hall sensor to determine whether the stepper motor has collided with the terminal includes: Calculate the duration of the i-th Hall signal and detect whether the duration is greater than Tthi*M; If not, determine that the stepper motor has not collided with the end; if yes, determine that the stepper motor has collided with the end. Where Tthi is the theoretical operating duration corresponding to the i-th rotational speed, and M is greater than or equal to 4.

5. The control method according to claim 1, characterized in that, Before entering the initialization phase, the process also includes: establishing a weight database; The i-th rotational speed is set to correspond to multiple specific operating ranges, and the weight value corresponding to the multiple specific operating ranges is set to Ni. When the specific operating range is the theoretical operating range, Ni < 0. When the specific operating range is a non-theoretical operating range, Ni > 0. The weight value matched by a specific operating range far from the theoretical operating range is greater than the weight value matched by a specific operating range close to the theoretical operating range.

6. The control method according to claim 5, characterized in that, The theoretical operating range is [(1-ΔT1)Tthi, (1+ΔT1)Tthi], 0≤ΔT1≤0.5, where Tthi is the theoretical operating duration corresponding to the i-th rotational speed, and the weight value matched for this theoretical operating range is set to N0, -1≤N0≤0.

7. The control method according to claim 6, characterized in that, The i-th rotational speed is defined to correspond to multiple specific operating ranges, including: Set a first specific operating range corresponding to the i-th rotation speed, and set the weight value matched by the first specific operating range to N1. The first specific operating range is (-∞, (1-ΔT1)Tthi) or ((1+ΔT1)Tthi, 2Tthi]; A second specific operating range is set for the i-th rotational speed, and the weight value matched by the second specific operating range is set to N2. The second specific operating range is (2Tthi, 3Tthi]; Set a third specific operating range corresponding to the i-th rotational speed, and set the weight value matched by the third specific operating range to N3, wherein the third specific operating range is (3Tthi, +∞); Among them, 1 <N1<N2<N3。 8. The control method according to claim 7, characterized in that, Detecting the i-th Hall signal generated by the Hall sensor to determine whether the stepper motor has collided with the terminal includes: Calculate the duration of operation of the i-th Hall signal and determine the target specific operating interval to which the duration of operation belongs; Find the target weight value corresponding to the specific operating range of the target, and accumulate them to obtain the current total weight; If the total weight is less than the preset total weight, the stepper motor is determined not to have collided with the end; if the total weight is greater than or equal to the preset total weight, the stepper motor is determined to have collided with the end, wherein the preset total weight ST≥N2+N3.

9. A control device for controlling an electronic expansion valve, characterized in that, The control device includes a main control module; The electronic expansion valve includes a stepper motor and a Hall sensor disposed near the stepper motor. The stepper motor is used to operate at a specific speed, and the Hall sensor is used to sense the magnetic field change caused by the rotation of the stepper motor to generate a corresponding Hall signal. The main control module is used to control the stepper motor to run at the i-th speed during the initialization phase of the electronic expansion valve, and to detect the i-th Hall signal generated by the Hall sensor to determine whether the stepper motor has collided with the end; if it is determined that the stepper motor has not collided with the end, the main control module controls the stepper motor to run at the (i+1)-th speed, and detects the (i+1)-th Hall signal generated by the Hall sensor to determine whether the stepper motor has collided with the end; if it is determined that the stepper motor has collided with the end, the initialization is completed, i = 1, 2, ...

10. A vehicle refrigeration device, characterized in that, include: The control device as described in claim 9.

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