Automatic test system and method for acr safety belt ecu

Abstract

This application provides an automatic testing system and method for an ACR seatbelt ECU. The system includes a functional status control module, a retractor motor, a tow motor, a tow motor control module, a calibration measurement module, and an isolated load module. The functional status control module sends functional status commands to the ECU under test and motor status commands to the tow motor control module. The tow motor control module sends motor drive signals to the tow motor based on the received motor status commands. The tow motor drives the motor shaft of the retractor motor to rotate to a target angle within a preset time window. The angle sensor of the retractor motor sends the motor shaft angle information of the retractor motor to the ECU under test in real time. The calibration measurement module receives the retractor motor control commands sent by the ECU under test and performs measurement calibration. The isolated load module simulates the load state of the ECU under test.

Description

Technical Field

[0001] This application relates to the field of vehicle safety technology, specifically providing an automatic testing system and method for ACR seatbelt ECU. Background Technology

[0002] An ACR (Active Control Retractor) seatbelt is a passive safety system in automobiles that actively tightens and releases the seatbelt via a motor. In an emergency, the ECU controlling the ACR seatbelt activates and drives the motor to tighten the seatbelt. The Hall effect step count (a step count obtained by the ECU based on the output signals of Hall sensors, used to characterize the relative position of the retractor motor or mechanism) increases accordingly. Simultaneously, the passenger's body, due to inertia, pulls the seatbelt out, causing the motor to passively reverse, and the Hall effect step count decreases. The ECU outputs different subsequent control sequences based on whether the Hall effect step count, determined by the combined effects of tightening and pulling, exceeds a threshold boundary. Therefore, the fundamental purpose of developing and testing an ACR seatbelt is to precisely adjust the Hall effect step count to preset positions on both sides of the threshold boundary, verifying whether the ECU outputs the expected control response under the corresponding boundary conditions.

[0003] The existing testing scheme relies on manual rotation of the retractor motor to complete the Hall step adjustment, which has the following obvious limitations: insufficient accuracy, it is difficult for manual operation to stop stably near the boundary verification point; the time window is difficult to match, there is a time constraint between the target step arrival time and the ECU response window, which is easy to cause missed judgments and false judgments; poor repeatability, even a small deviation near the threshold boundary can cause the ECU to output different responses, and it is difficult to form stable repeatability conditions manually.

[0004] Furthermore, if the retractor motor is directly connected to the ECU drive output, the ECU will immediately drive the motor to tighten after the function is activated, interfering with the Hall step count in real time. This will cause the test condition to be disrupted at the same time as it is established, making it impossible to stably enter the target test condition. Summary of the Invention

[0005] This application provides an automatic testing system for an ACR seatbelt ECU through embodiments, used to test the ECU under test, wherein the ECU under test is an ACR seatbelt ECU, and includes: a functional status control module, a retractor motor, a trailer motor, a trailer motor control module, a calibration measurement module, and an isolated load module; The functional status control module is used to send functional status commands to the ECU under test and to send motor status commands to the towing motor control module. The tractor motor control module sends motor drive signals to the tractor motor based on the motor status commands it receives. The towing motor drives the motor shaft of the retractor motor to rotate to the target angle within a preset time window based on the motor drive signal it receives. The angle sensor of the retractor motor is connected to the ECU under test and is used to send the motor shaft angle information of the retractor motor to the ECU under test in real time. The calibration measurement module is used to receive the take-up motor control command information sent by the ECU under test and perform measurement calibration; The isolated load module is connected to the motor drive output terminal of the ECU under test and is used to simulate the load state of the ECU under test.

[0006] This application also provides an automatic testing system for ACR seatbelt ECUs through embodiments. Using the aforementioned automatic testing system for ACR seatbelt ECUs to test the ECU under test includes the following operations: Operation 1: The calibration measurement module continuously receives control command information from the ECU under test; Operation 2: During the operation of the calibration measurement module, activate the ECU under test to put it into the active tightening stage, and drive the drag motor to rotate so that the motor shaft of the retractor motor rotates to the target angle before the judgment time of the ECU under test and remains there until after the judgment time.

[0007] The automatic testing system and method for ACR seat belt ECUs provided in this application decouples the power connection between the ECU under test and the retractor motor, thereby avoiding the problem that the retractor motor shaft angle cannot reach the angle threshold boundary due to the ECU's active control of the retractor motor. By using the auxiliary motor control module to drive the auxiliary motor to rotate, it ensures that the retractor motor shaft is stably and quantitatively adjusted to near the angle threshold boundary position and maintained in this state before the judgment time of the ECU under test. This overcomes the problem that the rotation angle of the retractor motor shaft is difficult to control quickly and accurately due to the inconsistency of operating speed and stopping accuracy when manually rotating the retractor motor, so as to maintain stable and consistent test conditions between different execution times of the same test scheme. Attached Figure Description

[0008] Figure 1 This is a schematic diagram of the working principle of an ACR seatbelt ECU; Figure 2 This is a schematic diagram of an ACR seatbelt ECU that generates different control commands based on the judgment result at the judgment moment; Figure 3 This is a schematic diagram of the test results under the direct connection test between the ACR seat belt ECU and the retractor motor. Figure 4 This is a schematic diagram of the architecture of an automatic testing system for an ACR seatbelt ECU provided according to an embodiment of this application; Figure 5This is a schematic diagram of an isolated load module provided according to an embodiment of this application; Figure 6 This is a schematic diagram of the ACR seatbelt ECU automatic testing method provided according to an embodiment of this application; Figure 7 This is a control timing diagram of the ACR seatbelt ECU automatic testing method provided according to an embodiment of this application; Figure 8 This is a schematic diagram of the test results of the ACR seat belt ECU automatic testing method provided according to the embodiments of this application; Figure 9 This is a schematic diagram of the architecture of the ACR seatbelt ECU automatic testing system provided according to an embodiment of this application; Figure 10 This is a schematic diagram of the architecture of the ACR seatbelt ECU automatic testing system provided according to an embodiment of this application; Figure 11 This is a schematic diagram of a switching circuit provided according to an embodiment of this application. Detailed Implementation

[0009] The present application will now be further described based on preferred embodiments and with reference to the accompanying drawings.

[0010] An ACR (Active Control Retractor) seatbelt is an intelligent automotive seatbelt that can anticipate and actively tighten. Its core actuators are the ECU (Electronic Control Unit), the retractor motor, and the retractor. The retractor motor has a built-in angle sensor, such as a Hall sensor, which communicates with the ECU to collect and send the angle information of the retractor motor shaft, such as Hall step values, to the ECU in real time.

[0011] Figure 1 The diagram illustrates the principle of how ACR seat belts provide active protection for vehicle occupants. Figure 2 This diagram illustrates the changes in current of the ACR seatbelt retractor motor and the Hall effect step count of the Hall sensor. Figure 1 , Figure 2As shown, when a vehicle experiences an emergency such as a collision and triggers the ACR seatbelt activation, the ACR seatbelt's operation can be roughly divided into an active tightening phase and a subsequent adjustment phase. In the active tightening phase, after receiving the trigger signal, the ECU outputs a preset control command sequence to the retractor motor electrically connected to it. This command is specifically a sequence of motor drive signals used to control the retractor motor to rotate in a preset positive rotation scheme (in the embodiments of this application, for ease of description, the retractor tightening direction is the positive direction of rotation, and the retractor unwinding direction is the negative direction of rotation), thereby driving the retractor to tighten the seatbelt to apply a restraining force to the human body. At the same time, the angle of the retractor motor shaft collected by the angle sensor increases.

[0012] Within a short period after the active tightening action is triggered, the human body tilts outward due to inertia, exerting a reaction force on the seatbelt. The seatbelt is pulled outward, causing the retractor motor to passively rotate in the negative direction. This causes the angle value of the retractor motor shaft, as measured by the angle sensor, to decrease. During this phase, the angle value measured by the angle sensor is jointly determined by the ECU driving the retractor in the positive direction and the seatbelt driving the retractor in the negative direction. When the outward tilt of the person is small, the angle of the retractor motor shaft only decreases slightly (e.g., Figure 2 The blue solid line shows the Hall step count variation curve. However, when the angle of the retractor motor shaft decreases significantly (e.g., when the person's outward tilt is large), the angle may drop drastically. Figure 2 The red dashed line in the middle shows the Hall step count variation curve.

[0013] Therefore, a decision point can be set after the moment the active tightening action is triggered, i.e., the start of the active tightening phase. At this decision point, the relationship between the angle of the retractor motor shaft and a preset angle threshold boundary is determined, and the subsequent control command sequence for the retractor motor is determined based on the decision result. Without loss of generality, the decision point can be set to be spaced apart from the start of the active tightening phase. That is, the duration of the active tightening phase is Then, it enters the subsequent adjustment phase.

[0014] like Figure 2 As shown, if the angle of the retractor motor shaft is greater than the preset angle threshold boundary at the judgment time, that is, the Hall step count is greater than the preset step count threshold, it indicates that only a small outward tilt has occurred (small outward tilt condition). The degree to which the human body pulls the retractor to reverse is not enough to make the angle of the retractor motor shaft fall below the angle threshold boundary, indicating that the emergency can be resolved. Therefore, in the subsequent adjustment stage, the ECU will send a preset reverse rotation control command sequence to control the retractor motor, and the angle of the retractor motor shaft will continue to decrease to loosen the seat belt.

[0015] Conversely, if the angle of the retractor motor shaft is less than the preset angle threshold at the judgment time, it indicates that the person's outward tilt is too large and continues until the judgment time. Therefore, in the subsequent adjustment phase, the ECU will send a preset positive rotation control command to the retractor motor to tighten the seat belt to ensure the safety of the person.

[0016] It is evident that the angle of the retractor motor shaft output by the angle sensor in the retractor motor is the core basis for the ECU to determine the current seat belt status and decide on the subsequent control sequence. The angle threshold boundary is the criterion for the ECU to switch responses between different control command sequences (adjustment command sequences that make the retractor motor rotate forward or backward). When the angle (Hall step count) is located on both sides of the angle threshold boundary, the ECU will generate different judgment results and output different subsequent control command sequences.

[0017] Based on the above working principle, during the functional development, debugging, and factory inspection of the ACR seatbelt ECU, it is necessary to test its response characteristics near the angle threshold boundary at the judgment moment. Specifically, it is necessary to ensure that the angle sensor in the retractor motor is in operation before the judgment moment (i.e., after the active tightening action is triggered). The signal (within) accurately reaches the vicinity of the threshold boundary and continues until the judgment time, in order to verify whether the ECU can accurately output the corresponding subsequent control command sequence based on the relative position of the angle of the retractor motor shaft and the angle threshold boundary at the judgment time.

[0018] The specific requirements of the aforementioned test scenarios increase the difficulty of conducting response tests on the ACR seatbelt ECU: such as Figure 3 As shown, if the motor drive output terminal of the ECU under test is directly electrically connected to the power terminal of the retractor motor, the motor drive command output by the ECU during the function activation phase will directly drive the retractor motor to rotate autonomously, thereby interfering with the external adjustment and control of the angle of the retractor motor shaft. This results in the inability to accurately control the angle of the retractor motor shaft to the preset angle threshold boundary, unless a mechanical device that can simulate the forward leaning action of a human body to pull the seat belt is designed at the same time. However, this will greatly increase the complexity of the test.

[0019] In addition, there are also test schemes that disconnect the electrical connection between the ECU and the retractor motor, that is, disconnect the connection between the motor drive output terminal of the ECU under test and the power terminal of the retractor motor, and adjust the angle by manually rotating the retractor motor, and rely on separate communication equipment and calibration measurement equipment to complete the function control and parameter acquisition. However, this test scheme can only achieve basic testing and has obvious limitations in the angle threshold boundary verification scenario: (1) Insufficient accuracy, manual operation is difficult to stably control the number of steps, and usually can only achieve a relatively coarse step positioning, and it is difficult to accurately stop near the boundary verification point. For scenarios that need to verify whether the angle of the retractor motor shaft triggers or does not trigger the function on a certain side of the angle threshold boundary, the accuracy of manual step control is difficult to meet the requirements; (2) The time window is difficult to match, and the interval between the tightening function trigger time and the judgment time is difficult to match. In shorter test scenarios, the angle adjustment of the retractor motor shaft needs to be completed within a very short time window. However, manually rotating the motor requires operation time and often cannot be rotated to the required position at the required time, which increases the uncertainty of the angle threshold boundary verification and is prone to missed judgment and misjudgment; (3) Poor repeatability makes it difficult to form stable repeated test conditions. Manual operation is greatly affected by the operator's habits, force, speed and observation time. When the same test case is executed repeatedly, the results fluctuate significantly, especially near the angle threshold boundary. Small deviations can lead to different control responses output by the ECU.

[0020] Furthermore, while this method of directly disconnecting the electrical connection between the ECU and the retractor motor (i.e., disconnecting the power flow) can prevent the retractor motor from being directly driven by the ECU, the motor drive output of the ECU will be in a floating or abnormal load state that is different from the actual connection state of the retractor motor. Its electrical load state differs from the actual connection state of the retractor motor, and there is a significant difference between the electrical load state and the actual connection state of the retractor motor, causing the ECU's working conditions in the test state to deviate from the real scenario.

[0021] To address the aforementioned issues and achieve efficient, accurate, and repeatable testing of the ACR safety point ECU boundary response, this application provides an automated testing system for the ACR seatbelt ECU. Figure 4 The diagram illustrates the architecture of the automated testing system for the ACR seatbelt ECU in one specific embodiment, as follows: Figure 4 As shown, this automated testing system can be used to perform precise and controllable testing of the boundary response of the ACR seatbelt ECU under test. In the following explanation, for ease of clarification, "ECU under test" will be used to refer to the ACR seatbelt ECU under test. For example, Figure 4The ECU under test being tested is ECU-1. It is understood that before or after testing this ECU, it can be replaced with ECU-2, ..., ECU-N. These ECUs are all ACR seat belt ECUs, so similar ACR seat belt retractor motor control function tests can be performed.

[0022] Continue to refer to Figure 4 The automatic testing system for the ACR seatbelt ECU includes a functional status control module, a retractor motor, a tow motor, a tow motor control module, a calibration measurement module, and an isolated load module.

[0023] The functional status control module is communicatively connected to the ECU under test and the drive motor control module, and is used to send signals to the ECU under test (e.g., Figure 4 The ECU-1 sends functional status commands (including activation and reset commands) and motor status commands to the tow motor control module. The tow motor control module is electrically connected to the tow motor and sends motor drive signals to the tow motor based on the received motor status commands. The motor shaft of the tow motor is coaxially and fixedly connected to the motor shaft of the retractor motor. Based on the received motor drive signals, it drives the motor shaft of the retractor motor to rotate to the target angle within a preset time window. The angle sensor of the retractor motor is communicatively connected to the ECU under test and is used to send the motor shaft angle information of the retractor motor to the ECU under test in real time. The calibration measurement module is communicatively connected to the ECU and is used to receive the retractor motor control commands sent by the ECU under test and perform measurement calibration. The isolated load module is power connected to the ECU under test and is used to simulate the load state of the ECU under test.

[0024] The following provides a detailed explanation of the functions of each module and the optional implementation methods.

[0025] The functional state control module is used to control the ECU under test to enter or reset the test state. Specifically, when it is necessary to measure whether the ECU under test can issue the correct control command according to the urgency of the situation (motor shaft angle of the take-up motor), the functional state control module sends an activation command to the ECU, causing it to enter the active tightening stage. At this time, the ECU under test is in the test state, which will continue for a period of time after the judgment time. That is, from the moment the active tightening is triggered, after... The duration is determined to ensure that the complete response of the ECU during the active tightening phase and subsequent adjustment phase can be obtained, thereby completing a test experiment.

[0026] After completing a test experiment, the functional status module sends a reset command to the ECU under test, causing the ECU under test to exit the test state. After that, the ECU under test will no longer respond to the motor shaft angle of the retractor motor until it receives an activation command from the functional control module again.

[0027] The functional status control module also controls the rotation of the tow motor through the tow motor control module. Specifically, when the tested ECU is activated to enter the test state (or shortly thereafter, such as after 50ms), the functional status control module sends a motor status command to the tow motor control module to activate the rotation of the tow motor, thereby driving the retractor motor to simulate the motion state of the seat belt actively tightening and being pulled outward.

[0028] Motor status commands can be pre-defined based on the required testing conditions. These commands can include specifying the target angle the motor shaft of the tow motor needs to rotate to within a preset time window, and the duration for which it needs to maintain that target angle. Clearly, the preset time window is located after the activation moment of the ECU under test and before the judgment moment (as explained earlier, the judgment moment is the moment when the ECU under test compares the angle of the retractor motor's shaft with a preset angle threshold boundary). The target angle should be near the angle threshold boundary that allows the ECU under test to generate different subsequent adjustment stage control commands; that is, the difference between the target angle and the angle threshold boundary should not exceed a preset value (e.g., 360°) to avoid an excessively large difference that would render the test meaningless.

[0029] For example, if the goal of a test is to detect whether the ECU under test can correctly output the control command to release the seat belt when the angle of the retractor motor shaft has not dropped below the angle threshold boundary at the judgment time, then the target angle is a specified angle above the angle threshold boundary (e.g., 180° above the angle threshold boundary, i.e., half a turn). Correspondingly, the motor status command specifies that the motor shaft of the tow motor and the motor shaft of the retractor motor it drives must rotate from the initial angle (0°) to this specified angle before the judgment time begins, and continue until after the judgment time (e.g., after the ECU under test exits the test state). Then rotate back to the initial angle; for example, if the goal of a test is to detect whether the ECU under test can correctly output the control command corresponding to releasing the seat belt when the angle of the retractor motor shaft has dropped below the angle threshold boundary at the judgment time, then the target angle is a specified angle below the angle threshold boundary (for example, 240° below the angle threshold boundary, i.e., 2 / 3 turn). Correspondingly, the motor status command is to specify that the motor shaft of the tow motor and the motor shaft of the retractor motor it drives rotate from the initial angle to the specified angle before the judgment time begins, and continue until after the judgment time, and then rotate back to the initial angle.

[0030] In some preferred embodiments, the motor status command may also include a curve showing the change of the angle of the motor shaft of the tractor motor over time as it rotates from an initial angle to a target angle, i.e., the curve showing the change of the rotation angle before the determination time begins. In other words, in addition to specifying the target angle, the rate of change of the angular velocity before reaching the target angle may also be specified to more accurately simulate the state changes during the period when the seat belt is pulled out.

[0031] After receiving the motor status command, the tow motor control module sends a corresponding drive signal to the tow motor to drive it to rotate. The motor shaft of the tow motor and the motor shaft of the retractor motor are coaxially connected through a coupling or other fixed connection method. Under the drive of the tow motor, the motor shaft of the retractor motor rotates synchronously. At the same time, the angle sensor inside the retractor acquires the rotation angle information of the retractor motor shaft in real time and sends it to the ECU under test. For example, a Hall sensor can generate Hall step counts corresponding to the angle; another example is that a magnetoresistive sensor can output orthogonal SIN / COS analog voltage signals, and the precise rotation angle can be obtained by calculating the ratio of these two signals; yet another example is that incremental or absolute encoders can generate digital codes in different formats, which also carry the angle information of the retractor motor shaft.

[0032] In the embodiments of this application, there are no particular limitations on the form of the auxiliary motor and the motor drive signal. Those skilled in the art can select a suitable auxiliary motor model and control method, as well as a suitable drive signal form, according to the testing requirements. For example, when the selected auxiliary motor is a stepper motor, the motor drive signal can be a pulse direction signal (STEP / DIR signal). The auxiliary motor control module sends the number of pulses and the direction signal corresponding to the target rotation angle to the stepper motor driver through serial communication. The stepper motor driver converts them into the corresponding phase sequence excitation current to drive the stepper motor to rotate to the preset angle. As another example, when the selected auxiliary motor is an AC servo motor, the motor drive signal can be a pulse command signal in the position control mode, and the servo driver controls the motor shaft to rotate to the target angle in a closed loop.

[0033] Meanwhile, the ECU under test communicates with the calibration measurement module through communication interfaces such as CAN. The calibration measurement module can continuously receive the control command sequence information sent by the ECU under test during the entire test and convert it into the corresponding calibration measurement results (such as the current change value of the retractor motor).

[0034] In some embodiments, the calibration measurement results generated by the calibration measurement module can be sent to the functional status control module. The functional status control module determines whether the ECU under test can output the correct retractor motor control commands based on the control commands output by the ECU under test after the determination time, combined with the comparison between the angle of the retractor motor shaft and the angle threshold boundary. In other embodiments, the calibration measurement results generated by the calibration measurement module can also be sent to the host computer together with the angle of the retractor motor shaft via wired or wireless communication for subsequent judgment.

[0035] As mentioned earlier, when testing whether the ECU under test can output a correct response in an emergency, the ECU under test does not actually drive the retractor motor; that is, the motor drive output terminal of the ECU under test is disconnected from the power terminal of the retractor motor. To ensure that the ECU motor drive output terminal is in an electrical state close to a real load under test conditions, in... Figure 4 In the illustrated embodiment, the motor drive output terminal of the ECU under test is connected to an isolated load module for replacing the electrical load of the take-up motor. Specifically, as shown in the example... Figure 5 As shown, the isolation load module is an RL circuit composed of an equivalent inductance and an equivalent resistance connected in series. The two ends of this RL circuit are respectively connected to the positive and negative terminals of the motor drive output of the ECU under test. The inductance value of the equivalent inductance and the resistance value of the equivalent resistance can be determined by measuring the stator inductance and internal resistance of the retractor motor. By connecting this isolation load module, the ECU under test can be in the same load state as the driving retractor motor, thereby improving the accuracy of the test.

[0036] In the embodiments of this application, the automatic testing system also includes a power supply module to supply power to each functional module in the automatic testing system. The specific implementation of the power supply module is not limited, and those skilled in the art can select a suitable power supply scheme according to the power supply requirements, operating voltage level and usage scenario of each functional module.

[0037] For example, the industrial real-time measurement and control platform host can be powered by standard AC mains power (AC 220V) converted by the built-in power module; the dual-channel CAN / CANFD communication interface card and serial port adapter can be powered through the USB interface or internal bus of the industrial real-time measurement and control platform host; the tractor motor can be powered by an independent DC regulated power supply or a power supply matching the motor driver, depending on its rated operating voltage; the ACR seat belt ECU under test can be independently powered by a DC regulated power supply simulating the vehicle power supply (typically 12V or 24V DC) to reproduce the power supply environment of the ECU in a real vehicle; if the dual-channel synchronous switching switch in the external motor isolation load module is implemented using a relay or electronic switch, it can also be powered by an independent low-voltage DC power supply or the platform control power supply. Electrical isolation should be maintained between each power supply branch to avoid power interference between different modules affecting the accuracy of the test signal. This application does not limit the specific implementation form of the power supply module.

[0038] In some specific embodiments, the control functions of the aforementioned functional state control module, calibration measurement module, and motor control module can be implemented in the form of executable programs and integrated into various selectable industrial real-time measurement and control platforms. The industrial real-time measurement and control platform can be carried by various industrial control hardware that supports real-time scheduling, such as a real-time controller based on NI CompactRIO, an industrial measurement and control chassis based on PXI architecture, or other industrial control hosts with real-time operating system support. The industrial real-time measurement and control platform can carry the communication links of the functional state control module, calibration measurement module, and motor control module respectively through its built-in or external CAN communication module and serial communication module, and coordinate the three modules to run collaboratively in the same test cycle under a unified scheduling mechanism to achieve timing alignment of functional state switching, parameter acquisition, and motor control.

[0039] Figure 6 A flowchart is shown illustrating an automated testing method for an ACR seatbelt ECU according to some embodiments of this application. This automated testing method can... Figure 4 This is implemented on the automated testing system shown. For example... Figure 6 As shown, this automated testing method includes the following operations: Operation 1: The calibration measurement module continuously receives control command information from the ECU under test; Operation 2: During the operation of the calibration measurement module, activate the ECU under test to put it into the active tightening stage, and drive the drag motor to rotate so that the motor shaft of the retractor motor rotates to the target angle before the judgment time of the ECU under test and remains there until after the judgment time.

[0040] Figure 7 The timing sequence of actions of the ECU under test, the motor drive module, and the calibration measurement module during the execution of this automated test method is further illustrated.

[0041] refer to Figure 6 , Figure 7 After the automatic test begins, the functional status control module first activates the calibration measurement module, enabling it to continuously receive control command sequence information from the ECU under test. Alternatively, as mentioned above, in some preferred embodiments, the calibration measurement module can first enter a continuous working state under the unified scheduling of the industrial real-time measurement and control platform.

[0042] Then, during the continuous operation of the calibration measurement module, the functional status control module sends an activation command to the ECU under test. The ECO triggers an active tightening action, and the control command corresponding to the active tightening action is synchronously sent to the calibration measurement module via a communication link such as CAN, in message or other optional formats. The calibration measurement module parses the command and generates the corresponding calibration measurement results, such as the curve of the required current of the retractor motor (i.e., the current that should be generated to execute the control command). It should be noted that since the motor drive output terminal of the ECO under test is not actually connected to the motor, this control command does not affect the state of the retractor motor.

[0043] Simultaneously with or slightly after the activation of the ECU under test (e.g., 10ms, 20ms, or 50ms), the functional status control module activates the towing motor control module. The towing motor control module then drives the towing motor and the coaxially connected retractor motor according to preset motor status commands, ensuring that they rotate to the target angle before the determination time of the ECU under test and remain there until after the determination time.

[0044] For example, in an optional embodiment, the time interval between the determination time and the activation time of the tested ECU is 1 second, and the target angle is greater than the threshold angle boundary of 180°. Under the drive of the towing motor, the retractor motor reaches the target angle 0.7 seconds after the tested ECU is activated, and remains at the target angle until the determination time, for example, until the functional state control module issues a reset command to the tested ECU and the towing motor control module.

[0045] For example, in another optional embodiment, the time interval between the determination time and the activation time of the tested ECU is 0.5s, the target angle is less than the threshold angle boundary of 240°, and under the drive of the towing motor, the retractor motor reaches the target angle 0.3s after the tested ECU is activated, and remains at the target angle until the determination time, for example, until the functional state control module issues a reset command to the tested ECU and the towing motor control module.

[0046] Clearly, the measurable operating limit of this automatic testing system, namely the minimum time interval between the judgment time and the activation time of the tested ECU, is determined by the maximum speed of the towing motor and the difference between the initial angle and the target angle. In other words, the time it takes for the towing motor to rotate the motor shaft of the retractor motor from the initial angle to the target angle at its maximum speed determines the minimum time interval after the activation time of the tested ECU to set the judgment time. Only by setting the judgment time greater than this time interval can it be ensured that the motor shaft of the retractor motor can reach the specified angle before the tested ECU makes the judgment.

[0047] During the execution of Operation 2, the angle sensor installed on the retractor motor sends angle information to the ECU under test in real time. Therefore, the ECU under test will automatically compare the motor shaft angle of the retractor motor with the angle threshold boundary at the judgment time, and send the corresponding control command sequence according to the comparison result. These control commands are also sent to the calibration measurement module in the form of messages, etc., and then the calibration measurement module parses and generates the corresponding calibration measurement results.

[0048] Figure 6 and Figure 7 This reflects the process and timing of an automated test of the ECU under test. After a sufficiently long time interval, such as 2s, 3s, or longer, after the determination time, the automated test can be ended. The functional status control module sends a reset command to the ECU under test and the towing motor control module, so that the ECU under test no longer responds to the angle information and the motor shaft of the retractor motor returns to the initial angle until the next test process begins.

[0049] The measurement and calibration module can enter working state before each automated test begins and exit working state after each automated test ends, or it can remain working state throughout multiple automated tests.

[0050] Figure 8 The illustration shows the measurement results obtained by performing the above-described automated test method twice (with the activation times aligned) in a specific embodiment. In the two tests, the target angle is set above and below the angle threshold boundary, respectively. It can be seen that the motor shaft of the retractor motor reaches the target angle before the determination time and maintains it until the determination time. At the determination time, the tested ECO issues the corresponding control command based on the detected angle of the retractor motor shaft.

[0051] Figure 9The figure illustrates the architecture of the automatic testing system constructed using an industrial real-time measurement and control platform (specific model) in a specific embodiment. As shown, the industrial real-time measurement and control platform integrates a functional control module, a calibration measurement module (which can use the standard XCP calibration measurement module built into the industrial real-time measurement module), and a drive motor control module. The functional control module and the XCP calibration measurement module communicate with the ECU under test through a dual-channel CAN interface card to achieve communication of various messages. The drive motor control module drives the drive motor through serial communication. The retractor motor is equipped with a Hall sensor, and the angle information sent to the ECU under test is the real-time Hall step count.

[0052] Figure 10 Another preferred embodiment of this application is shown, such as Figure 10 As shown, this embodiment is similar to Figure 4 The difference in the illustrated embodiment is that it also includes a switching circuit, which is used to switch the connection state between the motor drive output terminal of the ECU under test and the power terminal of the isolated load module or the retractor motor, so that the automatic test system can work between the motor isolation test mode and the motor access test mode, thereby expanding the application range of the automatic test system.

[0053] Figure 11 An alternative architecture for the switching circuit is shown, such as... Figure 11 As shown, the switching circuit consists of a dual-channel synchronous switching switch. Its common terminal is connected to the motor drive output terminal of the ECU under test, and its two sets of synchronous switching terminals are respectively connected to the power terminals of the isolation load module and the retractor motor. When the motor drive output terminal of the ECU under test is connected to the isolation load module, the automated test system operates in motor isolation test mode. This test mode is similar to... Figure 4 The illustrated embodiments are exactly the same and can be implemented in this mode. Figure 7 The automated testing method shown can be used to test other items of the ECU under test, such as, as described in the background art, by introducing a mechanical structure that can drive the seat belt to pull out a certain amount, and testing the response of the ECU under test when the retractor motor is controlled by both the ECU and the seat belt. In this case, the motor drive output terminal of the ECU under test can be directly connected to the power terminal of the retractor motor, so that the automated testing system enters the motor access test mode.

[0054] Understandable, Figure 11 The circuit shown does not constitute a limitation on the switching circuit. Those skilled in the art can also select other circuit forms that enable the automated test system to switch between motor isolation test mode and motor access test mode according to actual needs.

[0055] The specific embodiments of this application have been described in detail above. For those skilled in the art, several improvements and modifications can be made to this application without departing from the principle of this application, and these improvements and modifications also fall within the protection scope of the claims of this application.

Claims

1. An automatic testing system for an ACR seatbelt ECU, used to test an ECU under test, wherein the ECU under test is an ACR seatbelt ECU, characterized in that, include: Functional status control module, retractor motor, twin motor, twin motor control module, calibration and measurement module, and isolated load module; The functional status control module is used to send functional status commands to the ECU under test and to send motor status commands to the towing motor control module. The tractor motor control module sends motor drive signals to the tractor motor based on the motor status commands it receives. The towing motor drives the motor shaft of the retractor motor to rotate to the target angle within a preset time window based on the motor drive signal it receives. The angle sensor of the retractor motor is connected to the ECU under test and is used to send the motor shaft angle information of the retractor motor to the ECU under test in real time. The calibration measurement module is used to receive the take-up motor control command information sent by the ECU under test and perform measurement calibration; The isolated load module is connected to the motor drive output terminal of the ECU under test and is used to simulate the load state of the ECU under test.

2. The automatic testing system for the ACR seatbelt ECU according to claim 1, characterized in that, The preset time window is located after the activation time of the ECU under test and before the determination time. The determination time is the moment when the ECU under test compares the motor shaft angle of the retractor motor with the preset angle threshold boundary.

3. The automatic testing system for the ACR seatbelt ECU according to claim 2, characterized in that, The difference between the target angle and the angle threshold boundary does not exceed a preset value.

4. The automatic testing system for the ACR seatbelt ECU according to claim 3, characterized in that, The measurable operating limits of the automatic testing system for the ACR seatbelt ECU are determined by the maximum speed of the towing motor and the difference between the initial angle and the target angle.

5. The automatic testing system for the ACR seatbelt ECU according to claim 1, characterized in that, The drive motor is a stepper motor or an AC servo motor. The angle sensor of the retractor motor is a Hall sensor, a magnetoresistive sensor, an incremental encoder, or an absolute encoder.

6. The automatic testing system for the ACR seatbelt ECU according to claim 1, characterized in that, The isolated load module is an RL circuit composed of an equivalent inductance and an equivalent resistance connected in series. The two ends of the RL circuit are respectively connected to the positive and negative terminals of the motor drive output terminal of the ECU under test; The inductance and resistance values ​​of the equivalent inductance are determined by measuring the stator inductance and internal resistance of the retractor motor.

7. The automatic testing system for the ACR seatbelt ECU according to claim 1, characterized in that, It also includes a switching circuit for switching the connection status between the motor drive output terminal of the ECU under test and the power terminal of the isolated load module or the retractor motor.

8. The automatic testing system for the ACR seatbelt ECU according to any one of claims 1 to 7, characterized in that, It also includes a power supply module for powering the automatic testing system of the ACR seatbelt ECU.

9. An automatic testing method for an ACR seatbelt ECU, comprising testing the ECU under test using the automatic testing system for an ACR seatbelt ECU as described in claim 1, characterized in that, Includes the following operations: Operation 1: The calibration measurement module continuously receives control command information from the ECU under test; Operation 2: During the operation of the calibration measurement module, activate the ECU under test to put it into the active tightening stage, and drive the drag motor to rotate so that the motor shaft of the retractor motor rotates to the target angle before the judgment time of the ECU under test and remains there until after the judgment time.

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