Industrial-grade electromagnetic boosting arm device with fault self-diagnosis and passive safety modes

Abstract

The invention belongs to the field of mechano-electronics and industrial automation control, and particularly relates to an industrial-grade electromagnetic boosting arm device with a fault self-diagnosis and passive safety mode, which comprises a loading seat integrated with a circuit board. The device comprises an electromagnetic driving execution module, a multi-mode sensing acquisition module, a self-adaptive signal conditioning module, a real-time fault diagnosis module, a passive safety decision module and a dynamic trajectory planning module. Through the dynamic filtering and phase locking technology of the adaptive signal conditioning module, the interference of the noise of the power switch on the signal of the rotary transformer is effectively suppressed, and the accuracy of fault diagnosis and the positioning precision of the device are remarkably improved. A multi-dimensional parallel diagnosis mechanism of the real-time fault diagnosis module can identify potential faults of a motor, a transmission chain and a sensor in an early stage, and device performance deterioration caused by fault accumulation is avoided.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of mechanical electronics and industrial automation control, and specifically relates to an industrial-grade electromagnetic assisting arm device with fault self-diagnosis and passive safety mode. BACKGROUND

[0002] In the field of industrial automation, high-precision mechanical arm devices are the core equipment for realizing manufacturing tasks such as precision assembly and material handling. Electromagnetic assisting arms, as a key branch, provide precise force control and motion assistance through electromagnetic drive technology, and their performance is directly related to production quality and efficiency. The reliability and safety of the device are the basis for ensuring stable operation of industrial applications.

[0003] Among them, the industrial-grade electromagnetic assisting arm device with fault self-diagnosis function aims to improve the reliability of equipment operation through real-time monitoring and diagnosis. Such devices usually rely on high-precision position feedback elements such as rotary transformers to accurately obtain actuator states, thereby achieving early identification and warning of potential faults.

[0004] In the prior art, the excitation signal of the rotary transformer is easily disturbed by the switching noise of the power device, causing signal phase modulation distortion. When the device works in typical working conditions, common-mode noise is coupled to the excitation line through parasitic capacitance, causing significant phase shift and causing position calculation error to increase. The traditional LC filtering scheme is insufficient in suppressing noise near the switching frequency due to the cutoff frequency limit, and cannot effectively attenuate interference harmonics. This causes the position error to continuously accumulate during high-speed trajectory tracking, seriously exceeding the allowable range of industrial precision standards, affecting the positioning accuracy and operation safety of the device.

[0005] Therefore, the industrial-grade electromagnetic assisting arm device with fault self-diagnosis and passive safety mode is proposed to solve the above problems. SUMMARY

[0006] The purpose of the present application is to solve the technical problems raised in the background art by setting an industrial-grade electromagnetic assisting arm device with fault self-diagnosis and passive safety mode.

[0007] To solve the above technical problems, the technical scheme is as follows: the industrial-grade electromagnetic assisting arm device with fault self-diagnosis and passive safety mode includes a loading seat, and the loading seat is integrated with a circuit board. The device includes an electromagnetic drive execution module, a multi-modal sensing and collecting module, an adaptive signal conditioning module, a real-time fault diagnosis module, a passive safety decision module, and a dynamic trajectory planning module.

[0008] The electromagnetic drive execution module consists of a high-power-density permanent magnet synchronous motor and a harmonic reducer, with its output shaft connected to the robotic arm joint via a rigid coupling. The multimodal sensing acquisition module integrates a rotary transformer, a triaxial vibration sensor, and a temperature sensor. The rotary transformer is directly mounted on the motor rotor shaft to acquire the raw position signal, the triaxial vibration sensor is fixed to the joint housing to monitor the mechanical vibration spectrum, and the temperature sensor monitors temperature rise data in real time. An adaptive signal conditioning module is connected to the output of the multimodal sensing acquisition module. Internally, it includes a programmable gain amplifier, a digital anti-aliasing filter, and a phase-locked loop circuit. This module performs amplitude normalization and noise suppression on the raw excitation signal output from the rotary transformer. The real-time fault diagnosis module receives the conditioned sensor signal and uses an embedded diagnostic algorithm to perform parallel evaluations of the motor's operating status, the integrity of the mechanical transmission chain, and the sensor's health. The passive safety decision module generates a device safety level identifier based on the output of the real-time fault diagnosis module and triggers the corresponding passive safety operation mode according to a preset safety strategy. The dynamic trajectory planning module adjusts the robotic arm's motion trajectory in real time based on external commands and the device's safety status, ensuring smooth degradation or safe shutdown under fault conditions.

[0009] Furthermore, the specific workflow of the adaptive signal conditioning module is as follows: The programmable gain amplifier first dynamically adjusts the gain of the differential signal output from the resolver to stabilize its amplitude within the optimal input range of the analog-to-digital converter. The digital anti-aliasing filter adopts a multi-stage cascaded finite impulse response structure, and its cutoff frequency is dynamically configured according to the current motor frequency and power switching frequency to specifically attenuate switching noise harmonics. The phase-locked loop circuit includes a digital phase detector, a loop filter, and a voltage-controlled oscillator. It corrects the phase shift caused by common-mode noise in real time through a closed-loop feedback mechanism, ensuring that the demodulated reference signal and the excitation signal remain strictly synchronized.

[0010] Furthermore, the diagnostic logic of the real-time fault diagnosis module includes a motor condition diagnosis unit, a transmission chain diagnosis unit, and a sensor self-calibration unit. The motor condition diagnosis unit identifies winding short circuits, permanent magnet demagnetization, or bearing wear faults by analyzing the current harmonic distortion rate and the symmetry of the back electromotive force waveform. The transmission chain diagnosis unit detects fatigue cracks or backlash anomalies in the harmonic reducer 2 based on envelope spectrum analysis of vibration signals and correlation calculation of joint torque fluctuations. The sensor self-calibration unit performs sensor drift compensation and fault identification by comparing the consistency between the calculated position of the rotary transformer and the estimated position of the motor, combined with temperature sensor readings.

[0011] Furthermore, the passive safety decision module defines three device safety levels: normal operation level, performance degradation level, and emergency stop level. When the real-time fault diagnosis module detects no abnormalities, the device operates at the normal operation level, and the electromagnetic drive execution module operates at rated performance. When a non-critical fault is diagnosed, such as slight sensor drift or vibration amplitude approaching a threshold, the device switches to the performance degradation level. In this case, the dynamic trajectory planning module limits the maximum speed to 70% of the rated value and increases the damping coefficient of the position control loop to suppress oscillation risk. When a critical fault is diagnosed, including motor stall, transmission chain breakage, or complete sensor failure, the device immediately enters the emergency stop level. The passive safety decision module sends a braking command to the electromagnetic drive execution module, activating its built-in eddy current brake and mechanical brake, and reducing the joint torque to zero within 500 milliseconds.

[0012] Furthermore, the dynamic trajectory planning module employs a 7th-order polynomial interpolation algorithm to generate a smooth joint space trajectory. This module receives target pose commands from the upper-level controller and, combined with the device health status provided by the real-time fault diagnosis module and the safety level set by the passive safety decision module, reconstructs the trajectory parameters online. Under performance degradation, the module automatically extends the trajectory execution time and reduces jerk constraints to minimize impact on the mechanical structure. Under emergency stop, the module immediately interrupts the current trajectory and generates a zero-speed transition trajectory with the shortest possible time, ensuring the robotic arm stops smoothly with minimal overshoot.

[0013] Furthermore, the device includes a central arbitration unit connected to the circuit board, which is interconnected with all modules via a high-speed serial bus. The central arbitration unit periodically collects status data from each module, including signal conditioning quality indicators, fault diagnosis confidence levels, safety level indicators, and trajectory tracking errors. A pre-installed consistency verification algorithm within the central arbitration unit detects data conflicts or communication timeouts between modules. Based on preset priority logic, it overrides local decisions, directly forcing the device into a performance degradation level or emergency shutdown level to ensure the highest level of functional safety.

[0014] Furthermore, the eddy current brake of the electromagnetic drive actuator module consists of multiple sets of copper discs and excitation coils. When an emergency stop command is received, the passive safety decision module applies a 24-volt DC voltage to the excitation coil, inducing eddy currents in the discs to generate braking torque. Simultaneously, the electromagnet of the mechanical brake is de-energized, pressing the brake pads under the action of a spring to achieve mechanical locking. This dual-redundant braking design ensures that the device can still achieve a safe stop in the event of a single brake failure.

[0015] The beneficial effects of this invention are:

[0016] The dynamic filtering and phase-locking technology of the adaptive signal conditioning module effectively suppresses the interference of power switching noise on the rotary transformer signal, reducing the position calculation error to within 0.5%, and significantly improving the accuracy of fault diagnosis and device positioning. The multi-dimensional parallel diagnostic mechanism of the real-time fault diagnosis module can identify potential faults in the motor, drivetrain, and sensors at an early stage, avoiding device performance degradation caused by fault accumulation.

[0017] The hierarchical safety strategy of the passive safety decision-making module and the smooth degradation mechanism of the dynamic trajectory planning module enable the device to automatically take the optimal safety response when faced with faults of varying severity, ensuring the safety of equipment and personnel while maximizing production continuity. The unified monitoring and mandatory intervention capabilities of the central arbitration unit further enhance the functional safety integrity level of the device, meeting the stringent requirements of industrial applications for high reliability and safety. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] In the attached diagram:

[0020] Figure 1 This is a schematic diagram of the overall technical solution architecture of the industrial-grade electromagnetic assistive arm device proposed in this invention.

[0021] Figure 2 This is a schematic diagram of the core principle framework of the adaptive signal conditioning module in this invention;

[0022] Figure 3 This is a logical flow diagram of the real-time fault diagnosis module in this invention;

[0023] Figure 4 This is a schematic diagram of the multi-level interaction relationship and data flow between the passive safety decision-making module and the dynamic trajectory planning module in this invention;

[0024] Figure 5 This is a schematic diagram of the unified monitoring and mandatory intervention mechanism framework of the central arbitration unit of this invention;

[0025] Figure 6 This is a schematic diagram of the overall structure of the electromagnetic assist arm device in this invention;

[0026] Figure 7 This is an exploded view of the electromagnetic assist arm device in this invention.

[0027] Reference numerals: 1. Loading seat; 2. Harmonic reducer; 3. Circuit board; 4. Rigid coupling; 5. Triaxial vibration sensor; 6. Temperature sensor; 7. Permanent magnet synchronous motor; 8. Adaptive signal conditioning module; 9. Real-time fault diagnosis module; 10. Passive safety decision module; 11. Dynamic trajectory planning module; 12. Central arbitration unit; 13. Electromagnetic drive execution module; 14. Multimodal sensing acquisition module; 15. Joint housing; 16. Rotary transformer. Detailed Implementation

[0028] The exemplary embodiments of this disclosure are described below with reference to the accompanying drawings, including various details of the embodiments to aid understanding, and should be considered merely exemplary. Therefore, those skilled in the art will recognize that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of this disclosure. Similarly, for clarity and brevity, descriptions of well-known functions and structures are omitted in the following description.

[0029] Specific implementation examples are given below.

[0030] Please see Figures 1-7 This invention provides an industrial-grade electromagnetic power-assisted arm device with fault self-diagnosis and passive safety modes, including a loading base 1 on which a circuit board 3 is integrated. The device comprises an electromagnetic drive execution module 13, a multi-modal sensing acquisition module 14, an adaptive signal conditioning module 8, a real-time fault diagnosis module 9, a passive safety decision-making module 10, a dynamic trajectory planning module 11, and a central arbitration unit 12. All modules are interconnected via a high-speed serial bus, forming a closed-loop control and safety protection system.

[0031] The electromagnetic drive execution module 13, serving as the core of the device's power output, integrates a high-power-density permanent magnet synchronous motor 7 with a harmonic reducer 2. The rotor shaft of the permanent magnet synchronous motor 7 is directly connected to the robotic arm joint via a rigid coupling 4, and its stator windings employ a distributed winding process to reduce cogging torque ripple. The harmonic reducer 2 is fixed to the joint housing 15, and its output end is coupled to the output shaft of the permanent magnet synchronous motor 7, with a transmission ratio set to 1:100. This allows it to convert the high-speed, low-torque output of the permanent magnet synchronous motor 7 into the low-speed, high-torque required by the joint. The electromagnetic drive execution module 13 also integrates a dual braking mechanism: an eddy current brake and a mechanical brake. The eddy current brake consists of five sets of copper discs alternately stacked with excitation coils; the discs are 2 mm thick and have an outer diameter of 80 mm. The mechanical brake's brake pads are made of sintered friction material and are kept normally closed by a spring preload mechanism. When the device is in normal operation, the excitation coil is de-energized, and the electromagnet of the mechanical brake is energized and engaged to release the brake. When the emergency stop level is triggered, the excitation coil receives a 24-volt DC voltage excitation, the electromagnet of the mechanical brake is de-energized, and the spring force drives the brake pads to press against the brake disc.

[0032] The multimodal sensing acquisition module 14 is located inside the robotic arm and includes a rotary transformer 16, a triaxial vibration sensor 5, and a temperature sensor 6. The rotary transformer 16 is installed on the non-drive end of the rotor shaft of the permanent magnet synchronous motor 7 and must be close to the moving / rotating parts of the equipment (such as…). Figure 6 , 7 The stator and rotor gap is controlled within 0.1 mm to acquire the original excitation signal containing position information. The triaxial vibration sensor 5 is fixed to the inner wall of the joint housing 15 with epoxy resin. It needs to be attached to the vibration source or key area of ​​vibration transmission to ensure effective capture of vibration data. Its measurement range covers the mechanical vibration spectrum from 10 Hz to 2000 Hz, with a sampling rate of 5 kHz. The temperature sensor 6 uses a platinum resistance element and needs to contact the surface of the structure / component to be measured, meeting the contact measurement requirements for temperature monitoring. A four-wire connection method is used to eliminate lead resistance errors and monitor the winding temperature rise data in real time. All sensor signals are transmitted to the adaptive signal conditioning module 8 through shielded twisted-pair cables. The outer layer of the cable is wrapped with a metal braided mesh to suppress electromagnetic interference.

[0033] The multimodal sensing and acquisition module 14 is designed to achieve multi-dimensional sensing and acquisition of rotation parameters, vibration parameters and temperature parameters. It integrates the functional units of rotary transformer 16, triaxial vibration sensor 5, temperature sensor 6 and supporting components.

[0034] Although the rotary transformer 16, the triaxial vibration sensor 5, and the temperature sensor 6 are physically located separately, they are connected through circuit / signal links to achieve synchronous acquisition, transmission, or preprocessing of multiple parameters.

[0035] The adaptive signal conditioning module 8 is connected to the output of the multimodal sensing and acquisition module 14. Its hardware is based on a collaborative platform consisting of a programmable gain amplifier, a digital anti-aliasing filter, and a phase-locked loop circuit. Please refer to the appendix. Figure 2The programmable gain amplifier first dynamically adjusts the gain of the differential signal output from the resolver 16. The amplifier integrates automatic range switching logic; when the peak value of the input signal is detected to be below 30% of the analog-to-digital converter's range, the gain is increased by 2 times; when the peak value exceeds 90% of the range, the gain is decreased by 0.5 times, ensuring that the output signal amplitude remains stable within 70% to 85% of the optimal input range of the analog-to-digital converter. The digital anti-aliasing filter adopts a 4-stage cascaded finite impulse response structure, with each stage having an order of 64. Its cutoff frequency is dynamically configured based on the current electrical frequency of the permanent magnet synchronous motor 7 and the power switching frequency. Specifically, the configuration strategy is to use twice the power switching frequency as the reference cutoff frequency, and then superimpose the third harmonic offset of the permanent magnet synchronous motor 7's electrical frequency to form an adaptive filtering characteristic. The phase-locked loop circuit consists of a digital phase detector, a loop filter, and a voltage-controlled oscillator forming a closed-loop device. The digital phase detector compares the phase difference between the conditioned signal and the local reference signal, and outputs an error voltage to the loop filter. The loop filter employs a proportional-integral (PI) structure with an integration time constant of 100 microseconds and a proportional gain of 0.8. The voltage-controlled oscillator adjusts its output frequency based on the filtered error voltage to ensure that the reference signal remains in phase with the excitation signal of the rotary transformer 16, with a maximum tracking error not exceeding 0.01 radians.

[0036] The real-time fault diagnosis module 9 receives conditioned multimodal sensor data and performs three types of evaluation tasks in parallel using an embedded diagnostic algorithm. Please refer to the appendix. Figure 3 The motor condition diagnosis unit identifies faults by analyzing the current harmonic distortion rate and the symmetry of the back electromotive force waveform. The current harmonic distortion rate is calculated using Discrete Fourier Transform to extract the amplitudes of the fundamental and 7th harmonics. A winding short-circuit warning is triggered when the total harmonic distortion rate exceeds 8%. The back electromotive force waveform symmetry is assessed by calculating the ratio of the positive to negative half-cycle areas. If the ratio deviates from 1 by more than 15%, permanent magnet demagnetization is determined. The transmission chain diagnosis unit performs envelope spectrum analysis on the vibration signal. First, the vibration signal envelope is extracted using Hilbert Transform, and then a 1024-point Fast Fourier Transform is performed on the envelope. If the amplitude of the second harmonic component of the meshing frequency of the harmonic reducer 2 increases by more than three times the reference value in the envelope spectrum, fatigue cracks are determined to exist; if a low-frequency component at 0.5 times the meshing frequency is detected, backlash abnormalities are determined. The sensor self-calibration unit diagnoses by comparing the consistency between the position calculated by the rotary transformer 16 and the estimated position of the permanent magnet synchronous motor 7. The estimated position of the permanent magnet synchronous motor 7 is obtained by integrating the electrical angle, and the calculation formula is as follows:

[0037] ;

[0038] in: The estimated electrical angle position of the permanent magnet synchronous motor 7, i.e., the electrical angle, is used to describe the spatial phase relationship of the magnetic field of the winding of the permanent magnet synchronous motor 7.

[0039] electric angular velocity The integral over the time interval (0, t) is obtained by integrating the angular velocity over time to obtain the change in electrical angle from the initial moment to time t, which reflects the electrical angle rotation amplitude of the permanent magnet synchronous motor 7 rotor during this time.

[0040] This indicates the initial electrical angle position, obtained by calibration using rotary transformer 16, and serves as the reference starting point for position estimation.

[0041] The electrical angular velocity is calculated by measuring the three-phase voltage and current, and the initial position is calibrated by the rotary transformer 16. When the position deviation exceeds 0.1 radians within 5 consecutive sampling periods, the rotary transformer 16 is marked as faulty; at the same time, drift compensation is performed by combining the readings of the temperature sensor 6, with a compensation coefficient of 0.002 radians per degree Celsius.

[0042] The passive safety decision module 10 defines three device safety levels: normal operation level, performance degradation level, and emergency shutdown level. This module periodically receives fault identifiers and confidence level data output from the real-time fault diagnosis module 9 and maps them to safety levels according to a preset strategy. When the confidence level of all diagnostic units is above 95% and there are no abnormal identifiers, the device maintains the normal operation level. When the confidence level of any diagnostic unit drops to between 80% and 95%, or when a vibration amplitude is detected exceeding the threshold of 80% for 3 consecutive seconds, the device switches to the performance degradation level. When the 7-phase current of the permanent magnet synchronous motor exceeds twice the rated value for 100 milliseconds, the drivetrain diagnostic unit reports a breakage fault, or the sensor completely fails, the device immediately enters the emergency shutdown level. Please refer to the appendix. Figure 4 Under the performance degradation level, the passive safety decision module 10 sends a speed limit command and damping adjustment parameters to the dynamic trajectory planning module 11; under the emergency stop level, it simultaneously sends a braking trigger signal and a torque zeroing command to the electromagnetic drive execution module 13.

[0043] The dynamic trajectory planning module 11 uses a 7th-order polynomial interpolation algorithm to generate the joint space trajectory. This algorithm determines the trajectory parameters through eight boundary conditions, including the starting point position, velocity, acceleration, jerk, and the target point position, velocity, acceleration, and jerk. Under normal operating conditions, the jerk constraint is set to 1000 radians per cubic second, and the trajectory execution time is adaptively calculated based on the target position difference. When the device switches to a performance degradation level, the module automatically limits the maximum motion speed to 70% of the rated value, reduces the jerk constraint to 500 radians per cubic second, and extends the trajectory execution time by 1.5 times. Under emergency stop conditions, the module immediately interrupts the current trajectory and generates a zero-speed transition trajectory. This transition trajectory starts at the current position and ends at zero velocity, zero acceleration, and zero jerk, with the transition time strictly controlled within 500 milliseconds to ensure the robotic arm stops smoothly with an overshoot of less than 2%.

[0044] The central arbitration unit 12 establishes a periodic data exchange mechanism with all modules via a high-speed serial bus. Please refer to the appendix. Figure 5 This unit collects status data from each module every 1 millisecond, including signal conditioning quality indicators, fault diagnosis confidence, safety level indicators, and trajectory tracking errors. Signal conditioning quality indicators cover signal-to-noise ratio (SNR) and phase jitter data; a SNR below 20 dB indicates signal degradation. Fault diagnosis confidence is calculated by combining the historical accuracy of each diagnostic unit with real-time data quality, ranging from 0 to 100. The central arbitration unit 12 has a pre-installed consistency verification algorithm. This algorithm first compares the safety level mapping results between the real-time fault diagnosis module 9 and the passive safety decision module 10. If the level difference persists for 10 milliseconds without being eliminated, a mandatory intervention procedure is initiated. The mandatory intervention logic is based on priority design: when a communication timeout or data conflict is detected, if the phase current of the electromagnetic drive execution module 13 exceeds 1.5 times its rated value, it directly forces the system to enter the emergency shutdown level; if only sensor data is abnormal and the current is normal, it forces the system to enter the performance degradation level. All mandatory intervention records are written to non-volatile memory for subsequent analysis.

[0045] During the power-on initialization phase, each module executes a self-test procedure. The eddy current brake and mechanical brake of the electromagnetic drive execution module 13 undergo three reciprocating motion tests to ensure the braking mechanism is free from jamming. The rotary transformer 16 of the multimodal sensing acquisition module 14 outputs an amplitude calibration signal to verify the integrity of the measurement link. The adaptive signal conditioning module 8 initiates a self-calibration sequence, verifying gain accuracy and phase consistency by injecting a standard test signal. The real-time fault diagnosis module 9 loads the historical fault model database and initializes the threshold parameters of each diagnostic unit. The passive safety decision module 10 initially sets the safety level to the performance degradation level, switching to the normal operation level after all modules pass their self-tests. The dynamic trajectory planning module 11 preloads commonly used motion trajectory templates, including point-to-point motion, circular interpolation, and linear tracking modes. After establishing communication connections with each module, the central arbitration unit 12 initiates the first round of status data collection, completing the device readiness confirmation.

[0046] In a typical operating cycle, the multimodal sensing acquisition module 14 continuously acquires joint motion data. The rotary transformer 16 outputs a set of sine and cosine signals every 50 microseconds, with an amplitude range of ±5 volts. The triaxial vibration sensor 5 synchronously acquires vibration acceleration data, with a range of ±50 grams. The temperature sensor 6 updates the winding temperature value every 100 milliseconds, with a measurement accuracy of 0.5 degrees Celsius. The adaptive signal conditioning module 8 processes the raw signal in real time, and the programmable gain amplifier dynamically adjusts the gain factor according to the signal amplitude, with an adjustment step size of 0.5 times. Each stage of the digital anti-aliasing filter introduces a 0.5 microsecond group delay, and the total delay compensation for the four stages is uniformly corrected by the phase-locked loop circuit. The voltage-controlled oscillator output frequency of the phase-locked loop circuit tracks from 1 kHz to 10 kHz, with a locking time of less than 1 millisecond.

[0047] The real-time fault diagnosis module 9 executes a complete diagnostic loop every 10 milliseconds. The motor status diagnosis unit uses a sliding window Fourier transform with a window width of 20 sampling points to calculate the current harmonic distortion rate. The transmission chain diagnosis unit updates its envelope spectrum analysis every 100 milliseconds with a spectral resolution of 5 Hz. The sensor self-calibration unit compares position data every 5 milliseconds; when the temperature exceeds 100 degrees Celsius, it activates an enhanced calibration mode, increasing the sampling frequency to 1 kHz. All diagnostic results are accompanied by timestamps and confidence labels and are transmitted to the passive safety decision module 10 via a message queue.

[0048] After receiving diagnostic data, the passive safety decision module 10 completes a safety level decision within 2 milliseconds. The decision logic is implemented using a state machine, containing 5 intermediate states to handle the level transition process. Recovery from the performance degradation level to the normal operation level requires 30 consecutive seconds without any abnormal detection. Exiting the emergency stop level requires manual reset confirmation; the reset signal is transmitted to the central arbitration unit 12 via a separate hardwired connection.

[0049] The dynamic trajectory planning module 11 uses a 7th-order polynomial interpolation algorithm to solve joint trajectories in real time. The core of the algorithm is solving an 8-variable linear equation system, with the coefficient matrix inverted using LU decomposition, and a calculation period of 1 millisecond. During trajectory execution, the module continuously monitors the deviation between the actual position and the planned position. When the deviation exceeds 5 degrees, a replanning procedure is triggered. The replanning uses the current position as the new starting point and recalculates the remaining trajectory segments to ensure motion continuity.

[0050] The functional safety monitoring of the central arbitration unit 12 covers the entire device lifecycle. This unit maintains communication health status counters for each module. If no data is received from a module for three consecutive cycles, the module is marked as having a communication failure. Simultaneously, a watchdog timer runs internally within the unit, with a timing period of 100 milliseconds. If the main control program fails to refresh the timer on time, a device-level reset is triggered. All status data and intervention records are uploaded to the upper-level monitoring device via an industrial Ethernet interface, supporting remote diagnostics and maintenance.

[0051] This embodiment, through the detailed implementation structure described above, achieves high-precision position control, multi-dimensional fault diagnosis, and graded safety protection for an industrial-grade electromagnetic assistive arm device. The adaptive signal conditioning module 8 effectively suppresses power switch noise interference, controlling the position calculation error of the rotary transformer 16 to within 0.5%. The parallel evaluation mechanism of the real-time fault diagnosis module 9 can identify 95% of typical faults within 50 milliseconds. The graded response strategy of the passive safety decision module 10 enables the device to maintain 70% operational capability when facing non-critical faults, and ensures safe shutdown within 500 milliseconds under critical fault conditions. The unified monitoring architecture of the central arbitration unit 12 meets the stringent requirements of functional safety integrity in industrial environments, with a mean time between failures (MTBF) exceeding 10,000 hours.

[0052] In the description of this invention, it should be understood that the various forms of processes shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this disclosure can be executed in parallel, sequentially, or in different orders, as long as the desired results of the technical solutions provided in this disclosure can be achieved, and no limitation is imposed herein.

[0053] The above description is merely a preferred embodiment of the present invention and does not constitute a limitation on the scope of protection of this disclosure. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this disclosure should be included within the scope of protection of this disclosure.

Claims

1. An industrial-grade electromagnetic assist arm device with fault self-diagnosis and passive safety mode, comprising a loading base (1), wherein a circuit board (3) is integrated on the loading base (1), characterized in that: Also includes: The electromagnetic drive execution module (13) consists of a high power density permanent magnet synchronous motor (7) and a harmonic reducer (2), and its output shaft is connected to the joint of the robotic arm through a rigid coupling (4). The multimodal sensing acquisition module (14) includes a rotary transformer (16), a triaxial vibration sensor (5), and a temperature sensor (6). The rotary transformer (16) is installed at the output end of the permanent magnet synchronous motor (7) and is used to acquire the original position signal of the permanent magnet synchronous motor (7). The triaxial vibration sensor (5) is fixed on the joint housing (15) and is used to monitor the mechanical vibration spectrum. The temperature sensor (6) is used to monitor the temperature rise data in real time. The adaptive signal conditioning module (8) is connected to the output of the multimodal sensing acquisition module (14). It contains a programmable gain amplifier, a digital anti-aliasing filter and a phase-locked loop circuit. The programmable gain amplifier dynamically adjusts the gain of the differential signal output by the rotary transformer (16). The digital anti-aliasing filter adopts a multi-stage cascaded finite impulse response structure. The phase-locked loop circuit corrects the phase shift in real time through a closed-loop feedback mechanism. The real-time fault diagnosis module (9) receives the conditioned sensor signal and performs parallel evaluation of the operating status of the permanent magnet synchronous motor (7), the integrity of the mechanical transmission chain and the health of the sensor through the embedded diagnostic algorithm. The passive safety decision module (10) generates a device safety level identifier based on the output of the real-time fault diagnosis module (9) and triggers the corresponding passive safety operation mode according to the preset safety strategy. The dynamic trajectory planning module (11) adjusts the movement trajectory of the robotic arm in real time according to external instructions and the safety status of the device; The electromagnetic drive execution module (13), multimodal sensing acquisition module (14), adaptive signal conditioning module (8), real-time fault diagnosis module (9), passive safety decision module (10) and dynamic trajectory planning module (11) are all connected to the circuit board (3).

2. The industrial-grade electromagnetic assistive arm device with fault self-diagnosis and passive safety mode according to claim 1, characterized in that: The workflow of the adaptive signal conditioning module (8) includes: The programmable gain amplifier dynamically adjusts the gain of the differential signal output by the rotary transformer (16) to stabilize its amplitude within the optimal input range of the analog-to-digital converter. The cutoff frequency of the digital anti-aliasing filter is dynamically configured based on the current electrical frequency and power switching frequency of the permanent magnet synchronous motor (7); The phase-locked loop circuit includes a digital phase detector, a loop filter, and a voltage-controlled oscillator. It ensures that the demodulation reference signal and the excitation signal remain strictly synchronized through a closed-loop feedback mechanism.

3. The industrial-grade electromagnetic assistive arm device with fault self-diagnosis and passive safety mode according to claim 1, characterized in that: The real-time fault diagnosis module (9) includes a motor status diagnosis unit, a transmission chain diagnosis unit, and a sensor self-verification unit. The motor condition diagnostic unit identifies faults by analyzing the current harmonic distortion rate and the symmetry of the back electromotive force waveform. The transmission chain diagnostic unit detects abnormalities based on the envelope spectrum analysis of vibration signals and the correlation between joint torque fluctuations. The sensor self-calibration unit performs a diagnosis by comparing the consistency between the position calculated by the rotary transformer (16) and the position estimated by the permanent magnet synchronous motor (7).

4. The industrial-grade electromagnetic assistive arm device with fault self-diagnosis and passive safety mode according to claim 3, characterized in that: The motor condition diagnostic unit extracts the amplitude values ​​of the fundamental wave and the 7th harmonic wave through discrete Fourier transform and calculates the total harmonic distortion rate. A winding short circuit warning is triggered when the total harmonic distortion rate exceeds 8%. Symmetry is assessed by calculating the ratio of the area of ​​the positive half-cycle to the negative half-cycle of the back electromotive force waveform. If the ratio deviates from 1 by more than 15%, the permanent magnet is determined to be demagnetized.

5. The industrial-grade electromagnetic assistive arm device with fault self-diagnosis and passive safety mode according to claim 3, characterized in that: The transmission chain diagnostic unit extracts the vibration signal envelope through Hilbert transform; The envelope spectrum is obtained by performing a 1024-point Fast Fourier Transform on the envelope. If the amplitude of the second harmonic component of the meshing frequency of the harmonic reducer (2) is found to increase by more than three times the reference value in the envelope spectrum, then fatigue cracks are determined to exist. If a low-frequency component at 0.5 times the meshing frequency is detected, the backlash is determined to be abnormal.

6. The industrial-grade electromagnetic assistive arm device with fault self-diagnosis and passive safety mode according to claim 1, characterized in that: The passive safety decision module (10) defines three device safety levels, including normal operation level, performance degradation level and emergency shutdown level; When the real-time fault diagnosis module (9) does not detect any abnormality, the device is in normal operation level; When a noncritical fault is diagnosed, the device switches to a performance degradation level; When a critical fault is diagnosed, the unit immediately enters the emergency shutdown level.

7. The industrial-grade electromagnetic assistive arm device with fault self-diagnosis and passive safety mode according to claim 6, characterized in that: At the performance degradation level, the dynamic trajectory planning module (11) limits the maximum motion speed to 70% of the rated value, while increasing the damping coefficient of the position control loop; Under the emergency stop level, the passive safety decision module (10) sends a braking command to the electromagnetic drive execution module (13), activates its built-in eddy current brake and mechanical brake, and reduces the joint torque to zero within 500 milliseconds.

8. The industrial-grade electromagnetic assistive arm device with fault self-diagnosis and passive safety mode according to claim 1, characterized in that: The dynamic trajectory planning module (11) uses a 7th-order polynomial interpolation algorithm to generate a smooth joint space trajectory; This module receives target pose commands from the upper-level controller and reconstructs trajectory parameters online by combining the device's health status and safety level. At the performance degradation level, the module automatically extends the trajectory execution time and reduces the jerk constraint; Under the emergency stop level, the module immediately interrupts the current trajectory and generates a zero-speed transition trajectory with the shortest possible time.

9. The industrial-grade electromagnetic assistive arm device with fault self-diagnosis and passive safety mode according to claim 1, characterized in that: It also includes a central arbitration unit (12), which is connected to the circuit board (3) and interconnects with all modules via a high-speed serial bus; The central arbitration unit (12) periodically collects status data from each module, including signal conditioning quality indicators, fault diagnosis confidence, safety level identification and trajectory tracking error; The central arbitration unit (12) has a pre-set consistency verification algorithm. When a data conflict or communication timeout is detected between modules, the local decision is overridden according to the preset priority logic.

10. The industrial-grade electromagnetic assistive arm device with fault self-diagnosis and passive safety mode according to claim 7, characterized in that: The eddy current brake of the electromagnetic drive execution module (13) consists of multiple sets of copper discs and excitation coils; When an emergency shutdown command is received, the passive safety decision module (10) applies a 24-volt DC voltage to the excitation coil; When the electromagnet of the mechanical brake is de-energized, the brake pads are pressed together by the spring to achieve mechanical locking.

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