drive device

Abstract

The present application provides a kind of driving device.The problem of the present application is to detect the abnormality of driving device earlier.The driving device has: driving device, which acts along with mechanical movement by driving signal;Driving part (42), which outputs driving signal;Sensor circuit (44), which outputs object signal, the object signal is based on the voltage generated from the sensor (43) possessed by driving device and linked with action;Adjustment part (451, 452), which adjusts amplitude and phase to signal from driving part (42), generates reference signal;And comparison part (453), which compares reference signal with object signal, outputs comparison signal for detecting the abnormality of driving device.

Description

Technical Field

[0001] This disclosure relates to drive devices. Background Technology

[0002] Anomaly detection device is known for detecting abnormalities in drive devices that undergo mechanical motion via drive signals. For example, Patent Document 1 discloses an anomaly detection device for an optical deflector, which includes: a mirror section; a support section supporting the mirror section; an actuator that causes the mirror section to oscillate relative to the support section about an oscillation axis by being applied a drive signal; and a sensor section that outputs a sensor signal based on the oscillation of the mirror section. This anomaly detection device generates predictive data based on the phase difference between the drive signal of the optical deflector and the sensor signal, and detects anomalies in the sensor signal by comparing the result of A / D conversion of the sensor signal with the predictive data.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2023-160273 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] However, since the signal is compared with the signal data after A / D conversion of the sensor signal, it is theoretically impossible to detect anomalies earlier than the sampling period of the A / D conversion. On the other hand, in applications that combine lasers and optical deflectors, higher laser power is required for faster detection of optical deflector anomalies. Here, using a faster A / D converter can increase the detection speed, but high-speed A / D converters are expensive, correspondingly increasing the cost.

[0008] This disclosure was made in view of the above circumstances, and its purpose is to detect abnormalities in drive devices more quickly.

[0009] Methods for solving problems

[0010] The drive device disclosed herein includes: a drive device that operates in conjunction with mechanical motion via a drive signal; a drive unit that outputs the drive signal; a sensor circuit that outputs an object signal based on a voltage generated by a sensor included in the drive device and linked to the operation; an adjustment unit that adjusts the amplitude and phase of the signal from the drive unit to generate a reference signal; and a comparison unit that compares the reference signal with the object signal and outputs a comparison signal that detects an anomaly in the drive device.

[0011] According to the present invention, abnormalities of the drive device can be detected more quickly by comparing a reference signal with a target signal after adjusting the amplitude and phase of the signal from the drive unit. Attached Figure Description

[0012] Figure 1 This is a block diagram illustrating the structure of a lighting device according to an embodiment of the present disclosure.

[0013] Figure 2 This is a block diagram illustrating the structure of the driving circuit of a lighting device according to an embodiment of the present disclosure.

[0014] Figure 3 This is a block diagram illustrating the structure of the sensor circuit of a lighting device according to an embodiment of the present disclosure.

[0015] Figure 4 This is a diagram showing the structure of the drive adjustment section of the lighting device according to an embodiment of the present disclosure.

[0016] Figure 5 This is a diagram showing the structure of the phase adjustment section of the lighting device according to an embodiment of the present disclosure.

[0017] Figure 6 This is a diagram showing the structure of the comparative section of the lighting device according to an embodiment of the present disclosure.

[0018] Figure 7 These are schematic diagrams of the output or input waveforms of various modules of the lighting device according to embodiments of the present disclosure. (A) is a waveform diagram of the drive branch signal output from the drive unit, (B) is a waveform diagram of the object signal and reference signal input to the comparison unit, and (C) is a waveform diagram of the comparison signal output from the comparison unit.

[0019] Figure 8 This is a diagram illustrating the detection in an existing device that detects anomalies based on the conversion results of an A / D converter.

[0020] Figure 9 This is a diagram illustrating a variation of the lighting device according to an embodiment of the present disclosure.

[0021] Figure 10 This is a diagram illustrating a variation of the lighting device according to an embodiment of the present disclosure.

[0022] Figure 11 This is a diagram illustrating a variation of the lighting device according to an embodiment of the present disclosure.

[0023] Figure 12 This is a diagram illustrating a variation of the lighting device according to an embodiment of the present disclosure.

[0024] Figure 13This is a diagram illustrating a variation of the lighting device according to an embodiment of the present disclosure.

[0025] Explanation of reference numerals in the attached figures

[0026] 1…Lighting device, 2…Light source, 3…Light source driver, 4…Driver, 5…Control unit, 13, 24, 35, 36, 63, 64…Operational amplifier, 41…Optical deflector, 42…Driver, 43…Sensor, 44…Sensor circuit, 45…Anomaly detection device, 51…First amplitude adjustment unit, 52…First phase adjustment unit, 53…First comparator, 54…Second amplitude adjustment unit, 55…Second phase adjustment unit, 56…Second comparator, 61, 62…Synthesis unit, 421 …D / A converter, 422, 423, 441, 442…Amplifier, 443…A / D converter, 451…Amplitude adjustment section, 452…Phase adjustment section, 453…Comparator section, a…Drive branch signal, b…Object signal, c…Reference signal, C21…Capacitor, d…Comparison signal, D1, D2…Diodes, R11, R12, R21, R22, R23, R31, R32, R33, R34, R35, R36, R37, R38, R39…Resistors Detailed Implementation

[0027] Hereinafter, the illumination device of the anomaly detection apparatus having the embodiments of the present disclosure will be described with reference to the accompanying drawings. In the drawings, the same or equivalent parts are labeled with the same reference numerals.

[0028] Figure 1 This is a block diagram showing the structure of the lighting device 1. The lighting device 1 may be, for example, a LiDAR (Light Detection and Ranging) device that detects the distance to an object by irradiating a laser and measuring its reflected light, or an image device that projects an image onto a screen. The lighting device 1 includes a light source 2, a light source driving unit 3 that drives the light source, a driving device 4, and a control unit 5 that controls the operation of the lighting device 1.

[0029] The light source 2 is a laser diode or the like, for example, in the case of a LiDAR device, which emits a pulsed laser with a near-infrared wavelength of approximately 900 nm. The LiDAR device also includes a receiver (not shown) that receives the reflected light from the light source 2 after it has been reflected by an object.

[0030] The driving device 4 is a device that drives a driving equipment, which operates in conjunction with mechanical motion via a driving signal. For example, it is a light polarization device. The light polarization device uses a light deflector 41 to scan the illumination light from the light source 2. The light deflector 41 is, for example, a driving device composed of MEMS (Micro Electro Mechanical System) mirrors. The light deflector 41 uses mirrors rotating about mutually orthogonal axes to reflect incident light incident from a certain direction, which is then emitted as scanning light. The driving device 4 can use piezoelectric, electrostatic, or electromagnetic actuators as actuators for the light deflector 41.

[0031] The drive unit 4 includes a drive unit 42 that supplies drive signals, which drive the actuator of the optical deflector 41. The optical deflector 41 is equipped with a sensor 43, which detects the movement accompanying the mechanical movement of the optical deflector 41. The sensor 43 generates a voltage linked to this movement as a sensor signal and inputs it to the sensor circuit 44, from which the sensor signal is output to the control unit 5.

[0032] The control unit 5 supplies a control signal, which serves as a drive signal, to the drive unit 42 in order to control the movement of the actuator of the optical deflector 41. The drive unit 42 then applies a drive signal to the actuator based on the control signal.

[0033] The drive unit 4 also includes an anomaly detection device 45 for detecting anomalies such as malfunctions of the optical deflector 41. A signal from the drive unit 42 and an object signal from the sensor circuit 44 are input to the anomaly detection device 45. The object signal and the sensor signal have the same frequency and phase; the object signal is a signal whose amplitude ratio has been adjusted by the sensor circuit 44. Furthermore, the anomaly detection device 45 outputs a signal showing the detection result to the control unit 5. The anomaly detection device 45 includes: an adjustment unit consisting of an amplitude adjustment unit 451 for adjusting the amplitude of the signal from the drive unit 42 and a phase adjustment unit 452 for adjusting the phase; and a comparison unit 453 that compares the amplitude- and phase-adjusted signal from the drive unit 42 (i.e., the reference signal) with the object signal.

[0034] The drive unit 42 outputs a signal with the same waveform (sine wave, triangle wave, sawtooth wave, etc.) and frequency as the drive signal to the amplitude adjustment unit 451 of the anomaly detection device 45. The amplitude adjustment unit 451 adjusts the amplitude of the input signal from the drive unit 42 to a predetermined value or a predetermined ratio relative to the amplitude of the signal from the drive unit 42.

[0035] The signal from the drive unit 42, whose amplitude has been adjusted by the amplitude adjustment unit 451, is then input to the phase adjustment unit 452. The phase adjustment unit 452 adjusts the phase to have a predetermined phase difference relative to the amplitude-adjusted signal from the drive unit 42. As a result, a reference signal for comparison with the target signal is generated in the next stage comparison unit 453. The reference signal is a signal with the same frequency, amplitude, and phase as the target signal when the optical deflector 41 is operating normally. Furthermore, in the above description, the signal from the drive unit 42 is input to the amplitude adjustment unit 451 for amplitude adjustment and then to the phase adjustment unit 452 for phase adjustment. However, it is also possible that the signal is initially input to the phase adjustment unit 452 for phase adjustment and then to the amplitude adjustment unit 451 for amplitude adjustment.

[0036] After the amplitude and phase are adjusted in the amplitude adjustment unit 451 and the phase adjustment unit 452, the signal from the drive unit 42 is input to the comparison unit 453 as a reference signal, as described above. An object signal, which is compared with the reference signal, is input from the sensor circuit to the comparison unit 453. Here, the input object signal, as described above, is a signal with the same frequency and phase as the sensor signal, and whose amplitude ratio has been adjusted; it is the signal before A / D conversion. The comparison unit 453 compares the object signal with the reference signal and outputs a comparison signal to detect an anomaly if the two signals are different. The comparison signal from the comparison unit 453 is sent to the control unit 5. The control unit 5 functions as an anomaly determination unit, determining whether an anomaly exists based on the comparison signal input from the comparison unit 453. Alternatively, the determination unit may be a separate device from the control unit 5, such as a reporting device that reports an anomaly.

[0037] Next, in Figure 2The diagram shows a block diagram illustrating the specific structure of the drive unit 42. The drive unit 42 includes a D / A converter 421, a first-stage amplifier 422 that amplifies the D / A converted drive signal, and a second-stage amplifier 423. Control signals, i.e., drive data, for driving the actuator are input from the control unit 5 to the D / A converter 421 of the drive unit 42. The D / A converter 421 performs D / A conversion on the drive data from the control unit 5, amplifies it through the first-stage amplifier 422 and the second-stage amplifier 423, thereby generating a drive signal, which is then output to the actuator of the optical deflector 41. Furthermore, a drive branch signal is output from a path branch between the output of the first-stage amplifier 422 and the input of the second-stage amplifier 423, serving as a signal from the drive unit 42. Since the branched drive branch signal is the output of the first-stage amplifier 422, it is a signal whose amplitude ratio is smaller than the amplification rate of the second-stage amplifier 423 relative to the drive signal; therefore, it is a signal with the same waveform, phase, and frequency. The drive branch signal from the output branch of the first-stage amplifier 422 is output to the amplitude adjustment unit 451 of the abnormality detection device 45. Here, as the signal output from the drive unit 42 to the amplitude adjustment unit 451, the drive signal can be used directly without using the drive branch signal.

[0038] Figure 3 This is a block diagram illustrating an example of the specific structure of the sensor circuit 44. The sensor circuit 44 includes a first-stage amplifier 441, a second-stage amplifier 442, and an A / D converter 443 that amplifies the sensor signal detected by the sensor 43. The sensor signal from the sensor 43 is amplified by the first-stage amplifier 441 and the second-stage amplifier 442, converted into digital data by the A / D converter 443, and output to the control unit 5. The conversion to digital data is performed by sampling the sensor signal according to the sampling frequency of the A / D converter 443. Furthermore, an output branch is provided from the path between the output of the first-stage amplifier 441 and the input of the second-stage amplifier 442, and a target signal is output from the branch point. The target signal is the output of the first-stage amplifier 441, and therefore is a signal whose amplitude ratio is smaller than the amplification rate of the second-stage amplifier 442 relative to the signal input to the A / D converter 443; it is an analog signal with the same phase and frequency. The target signal branched from the output of the first-stage amplifier 441 is output to the comparison unit 453 of the anomaly detection device 45.

[0039] Figure 4 This diagram illustrates an example of the specific structure of the amplitude adjustment unit 451. The amplitude adjustment unit 451 generates and adjusts the amplitude of the branched drive signal from the drive unit 42 as a reference signal for comparison with the target signal from the sensor circuit 44. Figure 4As shown, the amplitude adjustment unit 451 is a circuit that adjusts the amplitude by dividing the branched drive branch signal using resistors R11 and R12 and inputting it to the non-inverting terminal of the operational amplifier 13. This circuit adjusts the amplitude by changing the ratio of resistors R11 to R12. Here, as a method of changing the constants of resistors R11 and R12, for example, resistors R11 and R12 can be components with adjustable constants, such as digital potentiometers. The control unit 5 detects the amplitude of the sensor signal and adjusts the resistance values ​​of resistors R11 and R12 so that the amplitude is the same as the target signal input to the comparison unit 453. Alternatively, resistors R11 and R12 can be set as fixed resistors, and their resistance values ​​can be adjusted according to each device. Furthermore, amplitude detection is performed under specific conditions, such as during factory shipment, adjustment / maintenance, and device startup. Figure 4 A circuit is shown in which the amplitude is adjusted by dividing the drive branch signal using resistors R11 and R12 and inputting it to the non-inverting terminal of operational amplifier 13. However, the amplitude can also be adjusted by amplification without voltage division. In this case, for example, in Figure 4 In the middle, remove resistors R12 and R11, and connect a negative feedback circuit to the inverting input terminal of operational amplifier 13. Adjust the amplitude by adjusting the constant of the negative feedback circuit.

[0040] Figure 5 This diagram illustrates an example of the specific structure of the phase adjustment unit 452. The phase adjustment unit 452 adjusts the phase of the branched drive signal, after amplitude adjustment, so that it is approximately in phase or out of phase with the target signal, which is used to detect the movement of the optical deflector 41 driven by the drive signal. Whether it is adjusted to be in phase or out of phase depends on the structure of the comparison unit 453. Figure 5 This circuit changes only the phase characteristic without altering the amplitude characteristics of the signal input through the all-pass filter. Resistor R22 is the input resistor, and resistor R23 is the feedback resistor, negatively feeding the output of operational amplifier 24 to the inverting input terminal. Resistor R21 and capacitor C21 form an RC circuit; the phase is adjusted by changing the constants of resistor R21 and capacitor C21 to generate a reference signal. Here, as a method of changing the constants of resistor R21 and capacitor C21, for example, resistor R21 and capacitor C21 can be components with adjustable constants, such as digital potentiometers or variable capacitors. The control unit 5 detects the phase difference between the sensor signal and the drive signal and adjusts the resistance and capacitance values ​​accordingly. Alternatively, resistor R21 can be set as a fixed resistor, and capacitor C21 as a fixed capacitor, adjusting the resistance and capacitance values ​​according to each device. Furthermore, phase detection is performed under specific conditions, such as during factory shipment, adjustment / maintenance, and device startup.

[0041] Figure 6This diagram illustrates an example of the specific structure of the comparison unit 453. The comparison unit 453 compares the target signal and the reference signal and outputs a comparison signal. Here, the phase adjustment unit 452 adjusts the phase of the drive branch signal, after amplitude adjustment, to be the same as the phase of the target signal. Figure 6 In the first stage, a differential circuit is configured with resistor R31 connected to the inverting input terminal of operational amplifier 35, resistors R33 and R34 connected to the non-inverting input terminals, and resistor R32 provided as a feedback resistor. The second stage is configured as a comparator with a threshold voltage Vth connected to the non-inverting input terminal of operational amplifier 36 and the output of the differential circuit connected to the inverting input terminal. The target signal is connected to the inverting terminal of the differential circuit in the first stage, and a reference signal is connected to the non-inverting terminal. The differential circuit generates a differential signal between the target signal and the reference signal. The comparator in the second stage compares the threshold voltage Vth with the differential signal and outputs a comparison signal. Furthermore, the differential circuit in the first stage can also be changed to an adder circuit in the comparator section 453. In this case, the phase adjustment section 452 is adjusted so that the phase of the driving branch signal of the branch after amplitude adjustment is out of phase with the phase of the target signal.

[0042] then, Figure 7 A schematic diagram showing the output or input waveforms of each module of the drive unit 4 is provided. Figure 7 (A) shows in Figure 1 The waveform diagram of the signal output from the drive unit 42, i.e., the drive branch signal a, when the light deflector 41 is driven in the lighting device 1. Figure 7 (B) shows the waveforms of the target signal b and the reference signal c input to the comparison unit 453. Figure 7 (C) shows the waveform of the comparison signal d output from the comparison unit 453. Additionally, here, the target signal b and the reference signal c are normally out of phase, and an adder circuit is used as the operational amplifier 35 of the comparison unit 453.

[0043] The optical deflector 41 is a device that operates according to a drive signal. The sensor signal output from the sensor 43 installed on the optical deflector 41 is a signal indicating the mechanical movement of the optical deflector 41. Therefore, if the optical deflector 41 is operating normally, it outputs a sensor signal with the same frequency as the drive signal and a fixed amplitude ratio and phase difference. Therefore, by adjusting the amplitude and phase of the drive signal, the adjusted signal can be used as a reference signal indicating the normal operating state of the optical deflector 41. The drive signal is branched from the drive unit 42, and the drive branch signal with the same waveform and frequency as the drive signal is adjusted so that the amplitude and phase difference are the same as the object signal when the optical deflector 41 is operating normally, thus generating a reference signal. By comparing the generated reference signal with the object signal branched from the sensor circuit 44, in the event of an abnormality such as a malfunction of the optical deflector 41, the comparison signal changes, and the abnormality of the optical deflector 41 can be detected.

[0044] Compared to Figure 7 The driving branch signal a of (A), Figure 7 Before arrival time t, the object signal b (B) has the same frequency, amplitude ratio, and phase difference, and they are in a fixed relationship. Additionally, the reference signal c is adjusted to have the same amplitude and phase difference as the object signal when the optical deflector 41 is operating normally. The reference signal c and object signal b have the same frequency, the same amplitude, and a phase difference of 180°. Before arrival time t, the object signal b and reference signal c are in the aforementioned relationship, therefore... Figure 7 If the comparison signal d of (C) remains unchanged, it indicates that the optical deflector is normal. If, after a period of time, the optical deflector 41 malfunctions at time t, the object signal b drops sharply. Therefore, the comparison signal d changes, detecting an abnormality in the optical deflector 41.

[0045] In the illumination device 1 using a laser as the light source 2, when an anomaly occurs in the optical deflector 41, it is necessary to immediately detect the anomaly and stop the laser's emission. For example, consider the following scenario: when scanning a 0.1W visible light laser (wavelength: 400nm~700nm) by the optical deflector 41, the optical deflector 41 malfunctions, the laser scanning stops, and the laser illuminates only a single point. To safely stop the laser emission, the pulse energy needs to be below 77nJ. That is, the laser emission needs to stop within approximately 770ns. Furthermore, time is required to stop the laser emission after anomaly detection; therefore, anomaly detection needs to be performed faster than the aforementioned time. Additionally, the aforementioned time is inversely proportional to the laser power within a certain power range; for example, if it is 0.5W, it needs to be set to approximately 154ns or less.

[0046] For comparison, in Figure 8The image shows a conventional device that detects anomalies based on the conversion results of an A / D converter. Figure 8 The sensor signal and the A / D conversion result of converting the sensor signal into digital data are shown. When the sensor signal is converted to digital data by an A / D converter, data is acquired according to the sampling period of the A / D converter. Therefore, signals indicating abnormalities generated during the sampling period cannot be detected immediately, resulting in a detection delay. When detecting abnormalities based on the conversion result of the A / D converter, the abnormality of the optical deflector 41 and the A / D conversion are asynchronous, thus ensuring that the detection time is not shorter than the conversion period. By using a high-performance, high-speed A / D converter with a high sampling frequency, the detection speed can be improved, but high-speed A / D converters are expensive, with a cost difference of about 10 to 100 times compared to comparators of the same speed. On the other hand, according to the present invention, since the abnormality of the optical deflector 41 can be detected at high speed without using an expensive high-speed A / D converter, the laser emission can be quickly stopped when an abnormality occurs, ensuring safety at low cost.

[0047] (Variation Example 1)

[0048] In the above embodiment, anomaly detection, such as faults, is performed by comparing a reference signal (after adjusting the amplitude and phase of the drive branch signal) with the target signal. In contrast, a structure is further added that performs anomaly detection based on sensor data after A / D conversion of the sensor signal. After A / D conversion of the sensor signal in the sensor circuit 44, it is input to the control unit 5. The control unit 5 monitors changes in the sensor signal based on the input sensor data to detect anomalies. Here, in the case of detecting a fault occurring within a short period, anomaly detection is performed based on the comparison signal between the reference signal and the target signal; for faults or degradation occurring over a long period, anomaly detection is performed based on sensor data after A / D conversion of the sensor signal. This method enables the detection of both long-term degradation and momentary faults. Furthermore, in this case, the control unit 5 continuously monitors the sensor data after the sensor signal has undergone A / D conversion. Therefore, it can change the adjustment amount of the amplitude of the drive branch signal in the amplitude adjustment unit 451 to an appropriate value based on the amplitude of the sensor signal obtained through monitoring. In addition, it can change the adjustment amount of the phase of the drive branch signal in the phase adjustment unit 452 to an appropriate value based on the phase of the sensor signal obtained through monitoring.

[0049] (Variation Example 2)

[0050] The amplitude of the drive signal used to drive the actuator of the optical deflector 41 can be changed. The control unit 5 sends data indicating the change in the amplitude value of the drive signal to the drive unit 42 as drive data for generating the drive signal. As a result, the amplitude of the drive signal output from the drive unit 42 is changed. Here, when the amplitude of the drive signal is changed, the control unit 5 temporarily disables the abnormality detection processing of the abnormality detection device 45. Because the amplitude of the drive signal is changed, the drive branch signal is also changed, making it impossible to properly adjust the amplitude of the amplitude adjustment unit 451, potentially preventing the generation of a correct reference signal and thus hindering accurate abnormality detection. Therefore, for a certain period after the amplitude change, the abnormality detection processing of the abnormality detection device 45 is disabled, and erroneous detection is not performed. After the amplitude is changed, the amplitude adjustment unit 451 and the phase adjustment unit 452 are adjusted, and the abnormality detection processing is then enabled. The adjustment amount at this time is determined based on the amount of change in the amplitude of the drive signal, for example, by using the amplitude as a coefficient, or by using a predetermined table, etc. Alternatively, the adjustment amount can be determined based on the sensor signal detected by the sensor circuit 44.

[0051] (Variation Example 3)

[0052] In the above embodiment, a single sensor 43 detects the movement of the optical deflector 41 in response to a single drive branch signal, performing anomaly detection. Alternatively, sensors 43 can be provided to detect the movement of the optical deflector 41 in response to two or more drive signals, and anomaly detection can be performed on the sensor signals detected by each sensor 43. As an example, Figure 9A driving device is shown in which two driving signals, driving signal 1 and driving signal 2, are applied to the actuator of an optical deflector 41, respectively. Anomalies are detected based on sensor signals 1 and 2, which detect the movement of the optical deflector 41 based on each driving signal. Driving signals 1 and 2 are input to an amplitude adjustment unit 451 and a phase adjustment unit 452, respectively. The amplitude and phase of driving signal 1 are adjusted by a first amplitude adjustment unit 51 within the amplitude adjustment unit 451 and a first phase adjustment unit 52 within the phase adjustment unit 452. The amplitude and phase of driving signal 2 are adjusted by a second amplitude adjustment unit 54 within the amplitude adjustment unit 451 and a second phase adjustment unit 55 within the phase adjustment unit 452. A reference signal with adjusted amplitude and phase of driving signal 1 is input to a first comparison unit 53 within a comparison unit 453, and a reference signal with adjusted amplitude and phase of driving signal 2 is input to a second comparison unit 56 within the comparison unit 453. Furthermore, sensor signal 1 is input to the first comparison unit 53, and sensor signal 2 is input to the second comparison unit 56. A comparison signal between sensor signal 1 and a reference signal is output to perform anomaly detection based on sensor signal 1. Similarly, a comparison signal between sensor signal 2 and the reference signal is output to perform anomaly detection based on sensor signal 2. Moreover, instead of driving signal 1, the signal input to the first amplitude adjustment unit 51 can be a signal from the drive unit 42 with the same waveform and frequency as driving signal 1, i.e., drive branch signal 1. Likewise, instead of driving signal 2, the signal input to the second amplitude adjustment unit 54 can be a signal from the drive unit 42 with the same waveform and frequency as driving signal 2, i.e., drive branch signal 2.

[0053] (Variation Example 4)

[0054] In Variation 3, anomaly detection is performed separately for each sensor signal responding to two or more drive signals. In contrast, in Variation 4, the two or more drive signals and the individual sensor signals responding to them are combined into one for adjustment and comparison. As an example, Figure 10The driving device 4 is shown, in which driving signal 1 and driving signal 2 are respectively applied to the actuator of optical deflector 41, and sensor signal 1 and sensor signal 2 are output to detect the movement of optical deflector 41 based on each driving signal. Driving signal 1 and driving signal 2 are input to the synthesis unit 61, and the two signals are combined into one. Similarly, sensor signal 1 and sensor signal 2 are input to the synthesis unit 62, and the two signals are combined into one. The synthesis units 61 and 62 are, for example, differential circuits, adder circuits, etc. The driving signal combined by the synthesis units 61 and 62 is input to the amplitude adjustment unit 451 and the phase adjustment unit 452, and the amplitude and phase are adjusted to generate a reference signal. The reference signal is input to the comparison unit 453. In addition, the sensor signal combined by the synthesis unit 62 is also input to the comparison unit 453 for anomaly detection. In this way, two or more driving signals and sensor signals can be combined into one signal for processing, thus enabling simple anomaly detection. Alternatively, a signal from the drive unit 42 with the same waveform and frequency as drive signal 1, i.e., drive branch signal 1, can be used instead of drive signal 1. Similarly, a signal from the drive unit 42 with the same waveform and frequency as drive signal 2, i.e., drive branch signal 2, can be used instead of drive signal 2.

[0055] (Variation Example 5)

[0056] The comparisons in the comparison section 453 can also be performed using absolute values. Figure 11 This is an example of an absolute value circuit for comparison using the absolute value comparison unit 453. Operational amplifier 63, resistors R35 and R36, diodes D1 and D2 constitute a half-wave rectifier circuit. Furthermore, operational amplifier 64, resistors R37, R38, and R39 constitute an adder circuit. This circuit outputs positive and negative input signals as absolute value signals, enabling comparison.

[0057] (Variation Example 6)

[0058] In this embodiment, the comparison unit 453 directly compares the reference signal and the sensor signal. In contrast, in variation 6, the comparison unit 453 compares whether the respective signals of the reference signal and the sensor signal are specific voltage values ​​or voltage ranges, outputting comparison signal 1 and comparison signal 2. The control unit 5 detects abnormalities such as faults based on these comparison signals, i.e., comparison signal 1 and comparison signal 2. Figure 12The waveforms of the reference signal, comparison signal 1, sensor signal, and comparison signal 2 are shown. When the reference signal is within a specified voltage range, comparison signal 1 outputs "1". Similarly, when the sensor signal is within a specified voltage range, comparison signal 2 outputs "1". Since the sensor signal and the reference signal have the same frequency, phase, and amplitude, there is usually no difference between comparison signal 1 and comparison signal 2. Here, an anomaly occurs at time t, and the sensor signal drops sharply, falling within the specified voltage range. Therefore, comparison signal 2 continuously outputs "1" from time t. The output of "1" from time t onwards is inconsistent with comparison signal 1. Thus, when an anomaly such as a malfunction occurs, a difference arises between comparison signal 1 and comparison signal 2, allowing the control unit 5 to detect the anomaly by comparing the two signals.

[0059] (Variation Example 7)

[0060] The comparator 453 can also directly input the reference signal and the target signal to the comparator, using the comparison result as the comparison signal. For example, as Figure 13 As shown, the object signal b and the reference signal c are adjusted so that the amplitude of the reference signal c is slightly lower than that of the object signal b. In this state, when the comparator directly compares the object signal b and the reference signal c, under normal conditions, the comparison signal d repeatedly outputs "1" and "0" as a signal with a 50% duty cycle. Here, if an anomaly occurs at time t, and the object signal b drops sharply, the comparison signal d changes from "1" to "0". Thus, the duty cycle of the comparison signal d changes from 50%. In this way, when the duty cycle is not 50%, the comparison signal d changes from "1" to "0", thereby detecting anomalies.

[0061] Furthermore, in the above embodiments, a sine wave was shown as an example of a driving signal, but the driving signal can be any signal in which the voltage changes periodically. In addition to a sine wave, it can also be a triangular wave, a ramp wave, etc.

[0062] The embodiments of this disclosure have been described above, but the scope of this disclosure is not limited to the above embodiments, but includes the scope of the disclosure as set forth in the claims and its equivalents.

[0063] This application claims priority and interest in Japanese Patent Application No. 2024-219632, filed on December 16, 2024. In this specification, reference is made to the description, claims, and drawings of Japanese Patent Application No. 2024-219632, which are incorporated herein by reference in their entirety.

Claims

1. A driving device comprising: A drive device that operates in conjunction with mechanical motion via a drive signal; The driving unit outputs the driving signal; A sensor circuit that outputs an object signal, the object signal being based on a voltage generated by a sensor provided by the driving device and linked to the action; An adjustment unit adjusts the amplitude and phase of the signal from the drive unit to generate a reference signal; as well as The comparison unit compares the reference signal with the target signal and outputs a comparison signal that detects an abnormality in the drive device.

2. The driving device according to claim 1, wherein, The drive device includes a determination unit that determines an abnormality in the drive device based on the comparison signal.

3. The driving device according to claim 1, wherein, The reference signal has the same amplitude as the object signal when the operation is normal, and they are either in phase or out of phase.

4. The driving device according to claim 1, wherein, The drive device includes a control unit that determines the amount of adjustment the adjustment unit makes to the amplitude and phase. The sensor circuit sends the sensor data, after A / D conversion of the voltage generated by the sensor, to the control unit. The control unit determines the adjustment amount of the adjustment unit on amplitude and phase based on the sensor data.

5. The driving device according to claim 4, wherein, After the control unit disables the anomaly detection processing of the drive device based on the comparison signal, it adjusts the amplitude of the signal from the drive unit, and determines the adjustment amount of the adjustment unit based on the adjustment amount of the amplitude of the signal from the drive unit, thereby enabling the anomaly detection processing.

6. The driving device according to claim 1, wherein, The drive unit includes a control unit that detects abnormalities caused by long-term deterioration of the drive equipment. The sensor circuit sends the sensor data, after A / D conversion of the voltage generated by the sensor, to the control unit. The control unit detects abnormalities in the drive device based on long-term changes in the sensor data.

7. The driving device according to claim 1, wherein, The signal from the drive unit is a drive branch signal with the same waveform and frequency as the drive signal.

8. The driving device according to claim 1, wherein, The signal from the drive unit is the drive signal.

9. The drive device according to any one of claims 1 to 8, wherein, The driving device is an optical deflector.

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