Hybrid transmission cogwheel electromagnetic clutch control method and system
By combining multi-stage control, disengagement control, and abnormal protection mechanisms, the control accuracy and response issues of the gearbox electromagnetic clutch in hybrid electric vehicles during engagement and disengagement are solved, achieving efficient and reliable power switching and safety protection.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- KUNTAI VEHICLE SYST CHANGZHOU CO LTD
- Filing Date
- 2026-05-13
- Publication Date
- 2026-07-14
AI Technical Summary
Existing hybrid electric vehicle transmissions with toothed electromagnetic clutches suffer from speed differences and insufficient displacement stroke control precision during engagement and disengagement, which can easily lead to tooth knocking, impact, and incomplete engagement. During disengagement, the residual magnetism of the electromagnetic clutch and the residual torque of the load can cause incomplete separation and slow response. Furthermore, the abnormality monitoring mechanism is not perfect, which can easily cause component damage and affect the reliability and safety of the entire vehicle.
A multi-stage combined control method is adopted, including pre-magnetization, gear alignment, and position confirmation. The speed is adjusted by the motor controller to achieve engagement. Disengagement control adopts torque unloading, active demagnetization, and oscillating torque to eliminate residual torque. A full-scenario abnormality monitoring and three-level protection mechanism is established to monitor the clutch status in real time and execute protection actions in stages.
It significantly reduces tooth impact during meshing, improves meshing smoothness and reliability, enables rapid and drag-free separation, enhances system safety and durability, strengthens anomaly monitoring and protection mechanisms, and improves overall vehicle reliability and safety.
Smart Images
Figure CN122383784A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of hybrid vehicle transmission control technology, specifically relating to a control method and control system for the engagement, disengagement, and abnormal state handling of a dog clutch electromagnetic clutch applied to a hybrid transmission, implemented by a vehicle controller and a motor controller. Background Technology
[0002] Hybrid electric vehicle transmissions widely employ dog-clutch type electromagnetic clutches to switch power between the engine and electric motor, offering advantages such as zero slippage, high transmission efficiency, and compact structure. Existing control methods have the following shortcomings: The combined process has insufficient control precision for speed difference, displacement stroke and drive current, which can easily lead to tooth tipping, impact and incomplete meshing. During the separation phase, the separation is affected by residual electromagnetic magnetism and residual load torque, resulting in incomplete separation, slow response, and easy jamming. The abnormality monitoring mechanism is imperfect and lacks graded diagnosis and graded protection strategies. In the event of a fault, it is easy to cause damage to components and affect the reliability and safety of the whole vehicle.
[0003] Therefore, this invention proposes a control method and system for a hybrid transmission jaw-type electromagnetic clutch. Summary of the Invention
[0004] The purpose of this invention is to provide a control method and system for a hybrid transmission jaw-type electromagnetic clutch in order to solve at least one problem existing in the background art.
[0005] To achieve the above objectives, the present invention adopts the following technical solution. In a first aspect, the present invention provides a control method for a hybrid transmission jaw-type electromagnetic clutch, comprising: (1) Electromagnetic clutch engagement control: Receive engagement command, determine whether the speed difference between the two ends of the clutch and the load torque meet the engagement conditions; if they meet the conditions, perform pre-magnetization to eliminate free stroke, and adjust the motor speed through the motor controller to achieve tooth alignment of the driving and driven ends; then output holding current to make the teeth engage, and confirm engagement through the position sensor. (2) Electromagnetic clutch disengagement control: Receive disengagement command, unload load torque through motor controller; then cut off electromagnetic coil current and perform active demagnetization, and then apply motor oscillation torque by motor controller to eliminate residual engagement torque, so that the clutch disengages under the action of reset spring, and confirm the disengagement is completed by comprehensively using actuator stroke signal, speed difference signal at both ends and torque transmission status signal; (3) Electromagnetic clutch abnormality handling: Real-time monitoring of clutch working status, and based on the type, duration or number of abnormalities detected, the abnormality is judged as a minor abnormality, a moderate abnormality or a severe abnormality, and protective actions such as retry, limiting torque output or cutting off drive are performed in stages.
[0006] Preferably, the engagement condition is: the speed difference between the two ends of the clutch is less than the synchronous speed threshold, and the load torque is less than the allowable engagement torque.
[0007] Preferably, the confirmation conditions for disengagement completion are as follows: the clutch actuator stroke is reset to the initial position, the speed difference between the two ends is greater than the synchronous speed threshold, and it is confirmed that there is no torque transmission.
[0008] Preferably, the abnormal states include: tooth jacking, jamming, insufficient stroke, abnormal current, excessive speed difference, and excessive torque.
[0009] Preferably, the graded execution of protection actions includes: When it is detected that the top tooth or stroke is not in place during the engagement process, and the number of abnormalities is less than the preset number threshold, it is judged as a minor abnormality, and the clutch is controlled to re-execute the engagement control within the limited number of times. If the disengagement process fails to disengage, it is determined to be a minor abnormality. The motor controller is then instructed to increase the amplitude or frequency of the applied oscillation torque to assist in disengagement. When a moderate abnormality is detected, the transmission output torque is limited to a preset safe range. When a serious abnormality is detected, the drive output is forcibly cut off, the MIL light is illuminated, and the entire vehicle enters limp mode.
[0010] Preferably, if the minor anomaly is retried more than a preset number of times or the execution times out, it is upgraded to a serious anomaly and the corresponding serious anomaly protection action is executed.
[0011] Secondly, the present invention also proposes a hybrid transmission jaw clutch control system, including: an HTCU controller, a jaw clutch electromagnetic clutch, and a position sensor. The jaw-type electromagnetic clutch includes: an electromagnetic coil unit, a push ring assembly, a jaw disc, shaft teeth, and a return spring; The position sensor is used to collect the clutch displacement stroke in order to monitor whether the jaw disc is fully engaged; The HTCU controller is configured to execute the hybrid transmission jaw electromagnetic clutch control method.
[0012] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are: 1. The multi-stage combination control of pre-magnetization, tooth alignment, engagement maintenance, and position confirmation significantly reduces tooth impact and improves meshing smoothness and reliability.
[0013] 2. The disengagement control adopts torque unloading, active demagnetization, oscillation resistance reduction, and spring reset to eliminate residual magnetism and residual load, achieving rapid and drag-free separation.
[0014] 3. Establish a full-scenario anomaly monitoring and three-level protection mechanism to cover working conditions such as top gear, jamming, abnormal stroke, abnormal current, excessive speed difference, and excessive torque, thereby improving system safety and durability.
[0015] 4. The control logic is modular and easy to calibrate, adaptable to the integrated control architecture of hybrid transmissions, and has high engineering application value. Attached Figure Description
[0016] Figure 1 Control principle block diagram of the present invention Figure 2 This is a schematic diagram of the clutch engagement control process; Figure 3 This is a schematic diagram of the electromagnetic clutch disengagement control process; Figure 4 This is a schematic diagram of the abnormal handling and protection strategy for an electromagnetic clutch. Figure 5 This is a schematic diagram of the motor oscillation torque during the disengagement process of the electromagnetic clutch. Figure 6 A simplified diagram of a toothed electromagnetic clutch structure; Figure 7 This is a schematic diagram of the PID control logic for the electromagnetic coil current output.
[0017] Reference numerals in the attached diagram: 1. Push ring assembly; 2. Electromagnetic coil unit; 3. Toothed disc; 4. Return spring; 5. Spring baffle; 6. Disc teeth; 7. Shaft teeth; 8. Elastic retaining ring. Detailed Implementation
[0018] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0019] like Figures 1-7 As shown, this invention constructs a control method and system for a hybrid transmission toothed electromagnetic clutch.
[0020] like Figure 2 As shown, clutch engagement control: Triggering and monitoring start point: The vehicle controller (HTCU) issues a clutch engagement request and starts monitoring timing at the same time, requiring the monitoring time not to exceed the preset threshold T, so as to avoid engagement timeout from the source.
[0021] Speed synchronization preparation: The motor controller (MCU) performs synchronous speed regulation and torque control to create shock-free speed conditions for tooth clutch engagement, solving the core pain point of "tooth impact" in tooth clutches.
[0022] Combined with conditional judgment: Verify core states such as speed, torque, temperature, and power supply to determine whether they meet the conditions of the combined window. Meshing and position closed loop: The motor controller outputs a coil drive current, which is used to monitor the displacement of the dental disc in real time via a position sensor. Retry and Fault Degradation: After a synchronization failure, the cumulative number of failures is N, and the monitoring duration is checked to see if it exceeds 2T. If N > 3 and duration > 2T: the combination function is deemed to be faulty, the MIL light is illuminated, the instrument indicates that the gear is unavailable, the shifting process is terminated, and the system enters a fail-safe state.
[0023] like Figure 3 As shown, clutch disengagement control: This flowchart implements torque unloading, active disengagement, position monitoring, and fault safety during clutch disengagement. The core logic is as follows: Triggering and monitoring start point: The vehicle controller issues a clutch disengagement request and starts monitoring timing. The monitoring duration is required to not exceed the preset threshold T to avoid disengagement timeout.
[0024] Torque unloading preparation: The motor controller performs torque adjustment to complete power unloading, creating conditions for shock-free disengagement and avoiding damage to the tooth surface caused by disengagement under load.
[0025] Disengagement condition determination: Check torque, fault status, etc., to determine whether the disengagement condition is met; Decouple from the execution and location loop: The motor controller cuts off the coil drive current, the reset spring works, and the separation status of the dental disc is monitored in real time by the position sensor; Retry and Fault Degradation: After a failed disconnection, the cumulative number of times N is recorded, along with the number of verifications and the duration. If N > 3 and duration > 2T: the disengagement function is deemed to have failed, the MIL light is illuminated, the instrument panel indicates a transmission fault, the vehicle enters a limp state, the engine shuts off, and the highest level of safety protection is activated.
[0026] like Figure 4 As shown, the anomaly protection strategy is as follows: This flowchart realizes the abnormal monitoring, graded diagnosis and safety protection of the clutch throughout its entire life cycle. The core logic is as follows: Real-time status monitoring: The position sensor monitors the position status of the clutch in real time, serving as the core basis for anomaly detection.
[0027] Anomaly type determination: Determine whether the separation is abnormal (unintended separation without prior instruction). Determine if it is an abnormal combination Fault frequency and graded protection: Abnormal branch disconnection: Verification failure count N>3: Abnormal combination branch: Record the number of times N is disconnected, and verify that N > 3: like Figure 5 The diagram shows the motor oscillation torque during the disengagement process of the electromagnetic clutch: During the clutch disengagement execution phase, the motor controller outputs a short-term periodic oscillation torque, which acts on the driving and driven ends of the clutch to eliminate residual torque and mechanical jamming stress from the tooth meshing. This, in conjunction with the return spring, enables rapid and complete disengagement, avoiding problems such as incomplete separation, dragging, or jamming caused by residual load.
[0028] The motor oscillation torque is a dedicated auxiliary strategy for disengagement control, which is triggered only when all of the following conditions are met: 1. Clutch disengagement command received; 2. The load torque has been unloaded to within the clutch's allowable disengagement torque range; 3. The current to the electromagnetic coil has been cut off, and active demagnetization has been completed; 4. The position sensor detects that the dental disc has not entered the disengagement zone, or that there is a tendency for it to get stuck or stop moving. 5. No serious fault codes, and not in forced protection mode.
[0029] The timing of application must be strictly within the period between the completion of active demagnetization and the push action of the reset spring, neither too early nor too late, to ensure that only the self-locking of the tooth surface is eliminated and no additional impact is generated.
[0030] 2. Physical definition and control parameter confirmation of oscillating torque The oscillating torque is a low-frequency, small-amplitude alternating torque superimposed on the zero torque base point. It does not change the average speed of the driving and driven ends and is only used to disrupt the tooth surface contact stress.
[0031] Torque type: Sine wave alternating torque Amplitude range: 70%-90% of the rated maximum torque; Frequency range: 5Hz Duration: 100ms–150ms per segment Maximum total application time: ≤500ms (forced stop upon timeout) Application target: The motor controller applies pressure to the driving end of the clutch, while the driven end remains in a free or low-resistance state. 3. Method of applying oscillating torque and execution logic The HTCU sends an oscillation enable command to the MCU, which includes parameters for amplitude, frequency, and duration. MCU outputs a small positive torque → disconnects to overcome the maximum torque → half-cycle cyclic waveform; The position sensor samples the displacement every 1ms to determine the disengagement progress in real time. Once the dental disc is detected to have dislodged, the oscillation is immediately stopped, and the process proceeds to the reset confirmation stage. If the oscillation fails to break free in a single attempt, the retry mechanism will be automatically activated. First occurrence: Standard parameter oscillation; Second time: Amplitude +20%, frequency unchanged; Third adjustment: Amplitude +40%, frequency ±2Hz fine adjustment; If the connection fails to disengage after three retries, it is determined to be a disengagement jam, which is upgraded to a moderate / severe abnormality, and torque limiting or drive cut-off protection is implemented.
[0032] 4. The core role and technical effect of oscillating torque Eliminate frictional self-locking and residual engagement torque on the tooth surface of dental inserts; To counteract the adsorption resistance caused by electromagnetic remanence; Reduce the load on the return spring to prevent spring fatigue and jamming; Achieve rapid, thorough, and seamless separation, improving separation response time by more than 30%; Avoid tooth surface wear and tooth breakage caused by unloading or forcibly disconnecting under load.
[0033] like Figure 6 The diagram shows a simplified structure of a jaw-type electromagnetic clutch: the jaw-type electromagnetic clutch includes a push ring assembly 1, an electromagnetic coil unit 2, a jaw disc 3, a return spring 4, a spring baffle 5, disc teeth 6, shaft teeth 7, and an elastic retaining ring 8; when the electromagnetic coil unit 2 is energized, it generates electromagnetic attraction to drive the push ring assembly 1 to move, pushing the jaw disc 3 to mesh with the shaft teeth 7; after power is cut off, it disengages and resets under the action of the return spring 4; the position sensor monitors the displacement of the jaw disc 3 to achieve closed-loop monitoring of the engagement and disengagement states.
[0034] This clutch is an axially engaging dog clutch electromagnetic clutch, coaxially arranged in the power coupling path of the hybrid transmission, used for engaging and disengaging power between the engine and the motor / output shaft. It features an axially driven, spring-return, non-slip structure.
[0035] 2. Component Composition and Precise Functional Definition Electromagnetic coil unit 2: It is fixedly installed on the clutch housing / support and does not rotate with the shaft; Internally, it includes enameled wire windings, a magnetic housing, and an insulating frame; When energized, it generates a directional electromagnetic attraction; when the power is turned off, the magnetic field disappears rapidly. It supports three current modes: pre-magnetization, holding current, and active demagnetization.
[0036] Push ring assembly 1: Located between electromagnetic coil unit 2 and toothed disc 3, it is axially movable; It consists of a magnetic push ring, a bearing / sliding bushing, and a limiting structure; It receives electromagnetic attraction and transmits axial force to the toothed disc, thus driving engagement.
[0037] Dental disc 3 (driven disc): It can slide axially and connect to the driven shaft / gear in the circumferential direction; The end face is equipped with disc teeth, and the tooth shape is a trapezoidal tooth insert (good guidance, strong load-bearing capacity, and not easy to push the teeth). It contacts the push ring and engages / disengages as the push ring moves axially.
[0038] Shaft tooth 6 (driving tooth): It is interference-fitted or splined with the input shaft / motor shaft to fix the axial position; The end face tooth profile is perfectly matched with the disc tooth, and rigid transmission is achieved after meshing; The tooth tips are equipped with guide chamfers to facilitate tooth alignment and smooth meshing.
[0039] Return spring 4: It is a cylindrical helical compression spring, pre-tightened assembly; One end rests against the spring baffle 5, and the other end rests against the toothed disc 3; When the electromagnetic attraction disappears, a constant axial reset force is provided to push the dental insert 3 back to its initial position.
[0040] Spring baffle 5: Fixed to the shaft / housing, it is used for limiting and positioning the return spring, ensuring that the spring is centered, not skewed, and does not move.
[0041] Elastic retaining ring 8: Installed in the groove at the shaft end, it achieves axial limit positioning and prevents the toothed disc 3 from coming out or the parts from loosening.
[0042] Position sensor: It adopts a non-contact displacement sensor (Hall / magnetoelectric type), which has strong anti-interference and long life; It detects the absolute axial displacement of the dental insert with a resolution of ≤0.1mm and provides real-time feedback on the engagement / disengagement position.
[0043] 3. Key Structural Advantages No slippage, transmission efficiency ≥98%; It has a compact structure and small axial dimensions, and is highly integrated with the hybrid transmission layout. The toothed clutch has reliable meshing and can transmit large torques; The reset spring 4 is independently driven and separated, and does not rely on the motor for active dragging.
[0044] like Figure 7 The diagram shows the PID control logic for the electromagnetic coil current output: The HTCU sends a clutch target position signal, and the system calculates the position error between the target position and the actual position in real time; the target drive current is output through the position loop PID controller, and the current closed-loop regulation is completed in combination with the original current loop control logic, and finally the adapted drive current is output to the electromagnetic clutch actuator to achieve precise control and smooth output of engagement and disengagement actions; the position status is monitored in real time during the control process, and fault protection is triggered when abnormality occurs.
[0045] 1. Control Architecture and Control Objectives By employing dual closed-loop cascade control with position loop PID and current loop PID, the following can be achieved: The dental inlay displacement accurately tracks the target position; The coil current remained stable without any sudden changes. Engagement / disengagement is shock-free, tooth-triggering is non-overshooting; The entire location is closed-loop, and anomalies are identified very quickly.
[0046] 2. Control input signal Target position command: HTCU outputs according to the working conditions (fully engaged / fully disengaged / intermediate transition position); Actual position signal: The axial displacement of the dental disc acquired in real time by the position sensor; Actual current signal: Sampled value of current in the coil drive circuit; Operating condition auxiliary signals: speed difference, load torque, temperature, and power supply voltage.
[0047] 3. Control Process Position error calculation Real-time calculation of displacement deviation: ΔPOS = Pos_Target − Pos_Actual Pos_Target: Target location sent by HTCU Pos_Actual: Real-time feedback value from the position sensor Position loop PID control The position loop takes ΔPOS as input, performs PID calculations, and outputs the target drive current for the coil to achieve: Smooth convergence with small deviations; Fast response under large deviations; Eliminate static error and prevent overshoot and oscillation.
[0048] Output: I_target (target current).
[0049] Current loop PID control: The current loop uses I_target as the command and the actual coil current I_actual as feedback, and adjusts it via PID control. Rapidly track the target current; Limit the maximum current and minimum current; Limit the rate of change of current (di / dt) to prevent shocks.
[0050] Output: PWM duty cycle, directly driving the electromagnetic coil.
[0051] Execution and closed-loop feedback PWM drives the coil → push ring moves the toothed disc → position sensor samples in real time → continuously corrects ΔPOS → until the position error is less than or equal to the allowable threshold, control is complete.
[0052] 4. PID Control Constraints and Protection Logic If the position error exceeds the calibration threshold (e.g., >0.5mm) for 100ms, the position is considered out of control. If the current exceeds the limit or is insufficient, immediately cut off the output. If there is no displacement response (current present but no displacement), it is determined to be stuck / tooth malfunction. Any abnormal trigger will immediately exit PID automatic control and enter fail-safe mode.
[0053] 5. Control technology effectiveness Position control accuracy ±0.1mm; Meshing impact is reduced by more than 50%; The probability of tooth tipping decreases significantly; The actions are consistent and highly repeatable, making them suitable for batch engineering applications.
[0054] Based on the control logic disclosed in this invention, those skilled in the art can perform parameter adaptation and calibration without creative effort, and all such implementations fall within the protection scope of this invention.
[0055] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.
Claims
1. A control method for a hybrid transmission jaw-type electromagnetic clutch, characterized in that, include: (1) Electromagnetic clutch engagement control: Receive engagement command and determine whether the speed difference between the two ends of the clutch and the load torque meet the engagement conditions; Once satisfied, pre-magnetization is performed to eliminate free travel, and the motor speed is adjusted by the motor controller to achieve tooth alignment of the master and slave ends; then, a holding current is output to engage the teeth, and the engagement is confirmed by the position sensor. (2) Electromagnetic clutch disengagement control: Receive disengagement command, unload load torque through motor controller; then cut off electromagnetic coil current and perform active demagnetization, and then apply motor oscillation torque by motor controller to eliminate residual engagement torque, so that the clutch disengages under the action of reset spring, and confirm the disengagement is completed by comprehensively using actuator stroke signal, speed difference signal at both ends and torque transmission status signal; (3) Electromagnetic clutch abnormality handling: Real-time monitoring of clutch working status, and based on the type, duration or number of abnormalities detected, the abnormality is judged as a minor abnormality, a moderate abnormality or a severe abnormality, and protective actions such as retry, limiting torque output or cutting off drive are performed in stages.
2. The hybrid transmission jaw-type electromagnetic clutch control method according to claim 1, characterized in that, The engagement conditions are: the speed difference between the two ends of the clutch is less than the synchronous speed threshold, and the load torque is less than the allowable engagement torque.
3. The hybrid transmission jaw-type electromagnetic clutch control method according to claim 1, characterized in that, The specific conditions for confirming the disengagement are: the clutch actuator stroke is reset to the initial position, the speed difference between the two ends is greater than the synchronous speed threshold, and it is confirmed that there is no torque transmission.
4. The hybrid transmission jaw-type electromagnetic clutch control method according to claim 1, characterized in that, The abnormal conditions include: tooth jacking, jamming, insufficient stroke, abnormal current, excessive speed difference, and excessive torque.
5. The hybrid transmission jaw-type electromagnetic clutch control method according to claim 4, characterized in that, The hierarchical execution of protection actions includes: When it is detected that the top tooth or stroke is not in place during the engagement process, and the number of abnormalities is less than the preset number threshold, it is judged as a minor abnormality, and the clutch is controlled to re-execute the engagement control within the limited number of times. If the disengagement process fails to disengage, it is determined to be a minor abnormality. The motor controller is then instructed to increase the amplitude or frequency of the applied oscillation torque to assist in disengagement. When a moderate abnormality is detected, the transmission output torque is limited to a preset safe range. When a serious abnormality is detected, the drive output is forcibly cut off, the MIL light is illuminated, and the entire vehicle enters limp mode.
6. The hybrid transmission jaw-type electromagnetic clutch control method according to claim 5, characterized in that, If a minor anomaly is retried more than a preset number of times or the execution times out, it will be upgraded to a serious anomaly, and the corresponding serious anomaly protection action will be executed.
7. A hybrid transmission jaw-type electromagnetic clutch control system, characterized in that, include: HTCU controller, jaw clutch electromagnetic clutch, and position sensor; The toothed electromagnetic clutch includes: an electromagnetic coil unit (2), a push ring assembly (1), a toothed disc (3), shaft teeth (7), and a return spring (4); The position sensor is used to collect the clutch displacement stroke in order to monitor whether the jaw disc is fully engaged; The HTCU controller is configured to perform the hybrid transmission jaw electromagnetic clutch control method as described in any one of claims 1 to 6.