JP2006217697A - Speed controller for motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To attain smooth and highly precise feedback control by finely calculating motor speed. <P>SOLUTION: In detecting the edge of a pulse generated by the rotation of a motor and calculating a motor speed based on the edge, estimated speeds V<SB>01</SB>, V<SB>02</SB>and V<SB>03</SB>corresponding to elapsed times T<SB>01</SB>, T<SB>02</SB>and T<SB>03</SB>from a time point t<SB>0</SB>of a previous edge E1 at a predetermined sampling cycle are calculated until the next edge E2 has been obtained, if the next edge E2 is not obtained in a period from a time when the previous edge E1 is obtained to a time when a time of a previous edge cycle T<SB>0</SB>is reached. Thus, feedback control is performed using the estimated speeds. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an apparatus for controlling the speed of a motor used for opening and closing a rear door or window of a vehicle, for example.

  A motor control device generally includes a rotary encoder, a pulse detection circuit, a speed control circuit, and a motor drive circuit. The rotary encoder outputs a pulse corresponding to the rotation amount of the motor. For example, every time the window moves 0.75 mm, one pulse is output from the rotary encoder. The pulse detection circuit counts the pulses output from the rotary encoder and discretely detects the amount of rotation of the motor per unit time. The speed control circuit calculates the speed based on the rotation amount per unit time detected by the pulse detection circuit, compares the calculated speed with a predetermined target speed, and based on the comparison result, the motor Send control amount to drive circuit. The motor drive circuit drives the motor according to the received control amount. Thereby, the speed of the motor is controlled so as to follow the target speed.

  The following Patent Document 1 and Patent Document 2 disclose technologies for enabling accurate motor speed control. In Patent Document 1, it is determined whether or not there is a reference signal necessary for rotating the motor at a constant speed during a predetermined period of the FG signal generated according to the rotation speed of the motor. When there is no reference signal, a drive control signal is output to stop supplying the drive signal to the motor, thereby preventing the motor from malfunctioning due to reverse rotation runaway. In Patent Document 2, when the interval between the output pulses from the rotation detecting means that outputs a pulse proportional to the rotation period of the motor is longer than the first time, the motor is accelerated, and the interval between the output pulses is greater than the first time. If it is short, the motor acceleration is stopped or decelerated to control the motor at a constant speed, and when the acceleration is stopped or decelerated, if the output pulse interval is longer than the second time, the motor is accelerated. By doing so, constant speed control can be continued even if the motor does not have sufficient inertial force and stops if stop control is performed.

Japanese Patent Laid-Open No. 5-111277 (paragraph numbers 0005 to 0008) JP 7-154989 A (paragraph numbers 0005 to 0007)

By the way, in the motor speed control device, when calculating the motor speed based on the pulse output from the rotary encoder, the pulse cycle is measured by detecting the rising and falling edges of the pulse, and from this cycle There is a method for obtaining the speed of the motor. FIG. 6 shows this principle. Here, the sampling period is 5 ms, and pulse edge information is acquired at timings t ₀ , t ₁ , and t ₂ . Edge E1 is acquired at time _{t 0,} the speed _{V 0} = 1 / _T 0 on the basis of the period of the pulse _{T 0} (time from the edge E0 to the edge E1) is calculated at this point. Incidentally, the velocity _{V 0} exactly (same _V 1, _{V 2} below) representing the frequency. Next edge E2 is obtained at timing _{t 1,} the speed _{V 1} = 1 / _T 1 on the basis of the period _{T 1} of the pulse (the time from the edge E1 to the edge E2) are calculated in this time. The next edge E3 is acquired at timing _{t 2,} the speed _{V 2} = 1 / _T 2 on the basis of the cycle of the pulse _{T 2} (time from the edge E2 to the edge E3) is calculated at this point. In FIG. 6, since the relationship of T ₀ <T ₁ <T ₂ is satisfied, the speed of the motor is reduced.

The speed calculation method of FIG. 6, for example, the edge E1 velocity V ₀ at time t ₀ which is acquired is calculated, until the next edge E2 is obtained, the speed obtained at the acquisition time t ₀ of the edge E1 V At time t ₁ when ₀ is held and the edge E2 is acquired, a new speed V ₁ is calculated. In practice, however, the speed also changes in the section from the edge E1 to the edge E2. However, in the case of FIG. 6, since the changing speed value cannot be reflected in the feedback control, there is a problem that the control amount becomes discrete and rough, and smooth and highly accurate speed control cannot be performed. Further, when the motor stops and the edge of the pulse cannot be acquired, there is a problem that speed control becomes impossible. Furthermore, in the case of a motor that drives an opening / closing body such as a window, even if a foreign object is caught in the opening / closing body and the motor speed is reduced, the speed reduction amount is not calculated until the edge is acquired, so the detection of the jamming is delayed. There is a problem.

  The present invention solves the above-mentioned problems, and an object of the present invention is to enable smooth and highly accurate feedback control by finely calculating the speed of the motor. Another object of the present invention is to enable speed control even if a pulse edge due to rotation of a motor cannot be acquired. Still another object of the present invention is to quickly detect that a foreign object has been caught in the opening / closing body and to control the stop of the motor.

  A motor speed control device according to the present invention includes a detection unit that detects an edge of a pulse generated by rotation of the motor, a speed calculation unit that calculates a speed of the motor based on the edge of the pulse detected by the detection unit, Control means for controlling the motor so that the speed calculated by the speed calculating means is compared with a predetermined target value and the speed becomes the target value. When the next edge is not acquired within a predetermined time after the previous edge of the pulse is acquired, the speed calculation means obtains the previous edge acquisition time at a predetermined timing until the next edge is acquired. The estimated speed corresponding to the elapsed time from is calculated. The control means controls the speed of the motor based on the estimated speed and the target value in a section from when the predetermined time has elapsed until the next edge is acquired.

  When the motor speed is calculated by the speed calculation means, the speed can be calculated based on the pulse period (time from edge to edge). In this case, the frequency that is the reciprocal of the cycle is the motor speed. Therefore, the speed calculation means of the present invention includes a period calculation means and a frequency calculation means.

  In the present invention, if the next edge is not acquired within a predetermined time after the previous edge is acquired, the time corresponding to the elapsed time from the acquisition time of the previous edge is acquired until the next edge is acquired. An estimated speed is calculated. Since the feedback control is performed using the estimated speed and the target value, the speed changing between the edges can be reflected in the feedback control, thereby enabling smooth and highly accurate speed control. . Even if the motor stops at low speed due to a heavy motor load and the pulse edge cannot be acquired, feedback control is possible by performing the speed estimation calculation, and the motor operates normally. can do.

  In the present invention, the predetermined time after the previous edge is acquired is, for example, the time between the previous edge and the previous edge (in the present invention, this is referred to as “previous edge period”). Set to That is, when the next edge is not acquired after the previous edge has been acquired, the estimated speed corresponding to the elapsed time from the acquisition time of the previous edge is calculated.

  In this case, the speed calculation means calculates the speed of the motor at a constant sampling period, and based on the previous edge period for each sampling until the predetermined time (previous edge period) is reached after the previous edge is acquired. Speed can be calculated. In addition, after a predetermined time (previous edge cycle) has elapsed, until the next edge is acquired, the estimated speed can be calculated based on the time from the acquisition time of the previous edge to each sampling time point. .

  The present invention can be applied to an apparatus that controls the speed of a motor for opening and closing a rear door of a vehicle in a plurality of stages of acceleration, constant speed, and deceleration. In this case, the motor speed control device according to the present invention includes a storage unit that stores a target value of a predetermined speed corresponding to each of a plurality of stages, and a detection that detects an edge of a pulse generated by the rotation of the motor. Means, a speed calculating means for calculating the speed of the motor based on the edge of the pulse detected by the detecting means, and the tip speed of the rear door corresponding to the motor speed calculated by the speed calculating means in the storage means. Control means for controlling the motor so that the tip speed becomes the target value compared with the stored predetermined target value. The speed calculation means is a predetermined time until the next edge is acquired when the motor is in a deceleration state and the next edge is not acquired within a predetermined time after the previous edge of the pulse is acquired. At this timing, the estimated speed corresponding to the elapsed time from the acquisition time of the previous edge is calculated. The control means controls the speed of the motor based on the estimated speed and the target value in a section from when the predetermined time has elapsed until the next edge is acquired.

  According to this, the estimated speed is used even when the time until the next pulse edge is long in the section where the rear door approaches the fully open position (or the fully closed position) and the tip speed of the door decreases. Therefore, the tip speed can be controlled smoothly and accurately.

  The present invention can also be applied to an apparatus that controls the speed of a motor for driving the opening / closing body and detects that a foreign object has been caught in the opening / closing body. In this case, the speed control device for a motor according to the present invention includes a storage unit that stores a threshold for detecting pinching, a detection unit that detects an edge of a pulse generated by the rotation of the motor, and the detection unit. Speed calculating means for calculating the speed of the motor based on the edge of the pulse, fluctuation amount calculating means for calculating the fluctuation amount of the motor speed calculated by the speed calculating means, and speed calculated by the fluctuation amount calculating means Control means for comparing the amount of fluctuation with a threshold value stored in the storage means and controlling the motor to stop when it is detected that a foreign object is caught in the opening / closing body based on the comparison result. The speed calculation means calculates an estimated speed corresponding to the elapsed time from the acquisition time of the previous edge at a predetermined timing from when the previous edge of the pulse is acquired until the next edge is acquired. The fluctuation amount calculating means calculates an estimated fluctuation amount of the motor speed based on the estimated speed calculated by the speed calculating means. The control means detects the trapping of the foreign matter based on the estimated fluctuation amount and the threshold value, and stops the motor.

  According to this, an estimated speed corresponding to the elapsed time from the acquisition time of the previous edge is calculated from the acquisition of the previous edge to the acquisition of the next edge, and obtained based on this estimated speed. The trapping is detected by comparing the estimated speed fluctuation amount and the threshold value. For this reason, it becomes possible to stop the motor by detecting the pinching until the next edge is acquired, and it is possible to detect the pinching at an earlier stage than in the conventional case in which pinching is detected after the edge is acquired. Further, even when the motor cannot be rotated due to the pinching of a rigid body or the like and the edge of the pulse cannot be detected, the pinching can be detected by performing the speed estimation calculation.

  According to the present invention, smooth and highly accurate feedback control can be performed by finely calculating the motor speed between the edges of the pulse. Further, even when the pulse edge cannot be acquired, the speed control can be performed using the estimated speed. Furthermore, it is possible to quickly detect that a foreign object has been caught in the opening / closing body, and to stop the motor.

  FIG. 1 is a schematic mechanism diagram of a rear door opening / closing device (power tailgate) to which the present invention is applied. Reference numeral 1 denotes a vehicle, and a rear door 2 is rotatably supported by a hinge portion 3 at a rear portion thereof. 4 is a motor for opening and closing the rear door 2, 5 is a driving roller that rotates in the direction a according to the direction of rotation of the motor 4, 6 is an arm that reciprocates in the direction b according to the direction of rotation of the driving roller 5, 7 Is a stay that applies an urging force by a spring when the rear door 2 is opened and also acts as a damper when the rear door 2 is closed. When the motor 4 rotates, this rotation is transmitted to the driving roller 5 through a gear, the driving roller 5 rotates, and the rotation of the driving roller 5 is converted into a linear motion of the arm 6 through the gear. Since one end of the arm 6 is connected to the rear door 2, the rear door 2 rotates in the c direction about the hinge portion 3 by opening and closing the rear portion of the vehicle 1 by the reciprocation of the arm 6.

  FIG. 2 is a block diagram showing an electrical configuration of the rear door opening and closing device. Reference numeral 11 denotes a door opening / closing switch for instructing opening / closing of the rear door 2, which is provided in the driver's seat of the vehicle 1. Reference numeral 12 denotes a door full-closed detection switch that detects that the rear door 2 is completely closed, and includes a limit switch provided at the rear of the vehicle 1. Reference numeral 13 denotes a motor drive circuit that supplies current to the motor 4 to rotate the motor 4, and reference numeral 14 denotes a rotary encoder that generates pulses according to the rotation of the motor 4. Reference numeral 15 denotes a pulse detection circuit that detects a pulse output from the rotary encoder 14, and reference numeral 16 denotes an edge detection unit that detects edges (rising and falling) of the pulse detected by the pulse detection circuit 15. Reference numeral 17 denotes a speed calculation unit that calculates the speed V of the motor 4 based on the edge detected by the edge detection unit 16. Reference numeral 18 denotes a control unit that controls the speed of the motor 4, and 19 denotes a memory including a ROM, a RAM, and the like. The memory 19 stores in advance a target speed Vref corresponding to the target value in the present invention.

  In the above, the edge detection unit 16, the speed calculation unit 17, the control unit 18, and the memory 19 constitute the speed control device 50 for the motor 4. In the speed control device 50, the functions of the edge detection unit 16, the speed calculation unit 17, and the control unit 18 can be realized by a microcomputer. Here, the edge detection unit 16 constitutes an embodiment of the detection means in the present invention, the speed calculation unit 17 constitutes an embodiment of the speed calculation means in the present invention, and the control unit 18 corresponds to the control means in the present invention. The memory 19 constitutes an embodiment of the storage means in the present invention.

  FIG. 3 shows an example of the target speed Vref stored in the memory 19. Here, the target speed Vref represents the target speed of the front end 2A (see FIG. 1) of the rear door 2, but the target speed stored in the memory 19 may be the target speed of the motor 4. As shown in the figure, the value of the target speed Vref changes according to the door opening. The target speed Vref that increases with the door opening is set in the section X1 with a small door opening, and the target speed Vref that decreases with the door opening is set in the section X3 with a large door opening. In the middle section X2, the target speed Vref is set to a constant value regardless of the door opening.

  Therefore, considering the case where the rear door 2 operates from the fully closed state to the fully opened state (that is, when the door opens), the rear door 2 opens in an accelerated state for the first certain time after the opening (section X1), and thereafter The fixed time is opened at a constant speed (section X2), and the last fixed time is decelerated and is fully opened (section X3). On the other hand, considering the case where the rear door 2 operates from the fully open state to the fully closed state (that is, when the door is closed), the rear door 2 is closed in an accelerated state for a first fixed time after the start of closing (section X3), and thereafter Is closed at a constant speed for a certain period of time (section X2), and is finally decelerated for a certain period of time until it is fully closed (section X1). The speed control of the motor 4 is performed by the speed control device 50 so that the rear door 2 performs such an operation. The door opening degree of the rear door 2 can be measured using the pulse output of the rotary encoder 14. The control unit 18 reads the target speed Vref corresponding to the door opening degree from the memory 19, and controls the speed of the motor 4 via the motor drive circuit 13 based on the target speed Vref.

  That is, the door tip speed (speed of the tip 2A of the door 2) obtained by multiplying the rotation speed V of the motor 4 calculated by the speed calculator 17 by a predetermined gear ratio is compared with the target speed Vref, and the door tip speed is obtained. The controller 18 gives a command to the motor drive circuit 13 to feedback control the speed of the motor 4 so that becomes the target speed Vref. FIG. 4 shows a control system in this feedback control. Here, the control system has a known configuration including elements such as a proportional gain, an integrator, an integral gain, a feed forward gain, and an adder. In practice, this control system is realized as a function of a microcomputer. The control system of FIG. 4 performs PI control by proportionality and integration, but this is an example, and PID control by proportionality, integration, and differentiation may be performed.

  Next, details of the speed control of the motor 4 will be described with reference to FIG. 5A shows the speed of the motor 4 calculated by the speed calculation unit 17, FIG. 5B shows a pulse output from the pulse detection circuit 15, and FIG. 5C shows a sampling pulse for determining the timing for calculating the speed. Represents. Here, the sampling period is 5 ms, and the speed calculation unit 17 calculates the speed V of the motor 4 every 5 ms. In the following description, an example is given in which the rear door 2 is opening, the door opening is in the section X3 in FIG. 3, and the speed of the motor 4 is decreasing.

As shown in FIG. 5 (b), the the pulse edges E1 detected by the edge detection unit 16 are acquired at the sampling time point t _0, the speed calculation portion 17, the period T _{0 (edge} from the edge E0 of defined pulses Based on the time until E1, the motor speed V ₀ = 1 / T ₀ in FIG. 5A is calculated. This speed V ₀ accurately represents the frequency (the same applies to the motor speed calculated below). Then, the velocity calculation unit 17, the periodic T ₀ as a previous edge period, the next edge E2 in time of the previous edge period T ₀ from the acquired time t ₀ of the edges E1 to monitor whether acquired. As the speed of the motor 4 is reduced, since the period of the pulse is gradually increased, after obtaining the edge E1, next edge E2 within time T ₀ will not be acquired. Therefore, in this case, at the first sampling time t ₀₁ after T ₀ has elapsed, based on the elapsed time T ₀₁ (= T ₀ +5 ms) from the acquisition time t ₀ of the previous edge E1, FIG. Motor speed V ₀₁ = 1 / T ₀₁ is calculated.

Speed calculating unit 17 continues thereafter to monitor whether an edge E2 is obtained, if the edge E2 is obtained, at the next sampling time point t _02, from the acquisition time t ₀ of the previous edge E1 Based on the elapsed time T ₀₂ (= T ₀ +10 ms), the motor speed V ₀₂ = 1 / T ₀₂ in FIG. 5A is calculated. Speed calculating unit 17 continues to monitor thereafter further acquisition of the edge E2, if the edge E2 is obtained, at the next sampling time point t _03, the elapsed time T ₀₃ from the acquisition time t ₀ of the previous edge E1 ( = T ₀ +15 ms), the motor speed V ₀₃ = 1 / T ₀₃ in FIG. 5A is calculated. Thereafter, a pulse is risen, when the edge detector 16 a pulse of the edge E2 in is detected, the speed calculation unit 17 obtains the edge E2 at the next sampling time point t _1. Then, based on the determined pulse period T ₁ (time from the edge E1 to the edge E2), the motor speed V ₁ = 1 / T ₁ in FIG. 5A is calculated.

Thereafter, the cycle T ₁ as a new previous edge period, the next edge E3 from the acquisition time t ₁ within a time T ₁ of the edge E2 monitors whether acquired. Then, if the acquired next edge E3 in time _{T 1,} at the first sampling time point _{t 11 after T 1} is elapsed, the elapsed time from the acquisition point _{t 1} of the previous edge E2 _T 11 (= Based on (T ₁ +5 ms), the motor speed V ₁₁ = 1 / T ₁₁ in FIG. 5A is calculated. In the same manner, until the next edge E3 is obtained, at each sampling time point, based on the elapsed time from the acquisition point t ₁ of the previous edge E2, and calculates the motor speed. Then, it under Standing pulses, the pulse edge E3 in the edge detector 16 is detected, the speed calculation unit 17 obtains the edge E3 at the sampling time point t _2. Then, based on the determined pulse period T ₂ (time from the edge E2 to the edge E3), the motor speed V ₂ = 1 / T ₂ in FIG. 5A is calculated. Thereafter, the period T ₂ as a new previous edge period, repeats the above operation.

As described above, when the next edge is not acquired from the time when the previous edge is acquired to the time of the previous edge cycle, the speed calculation unit 17 until the next edge is acquired, The motor speed (V ₀₁ , V ₀₂ , V _03, etc.) corresponding to the elapsed time from the previous edge acquisition time is calculated at a sampling period of 5 ms. This motor speed is not an actual speed (V ₀ , V ₁ , V ₂ ) calculated from the determined pulse period, but an estimated speed calculated based on the elapsed time. The speed estimation section shown in FIG. 5A indicates a section for which the estimated speed is obtained.

  In the conventional case of FIG. 6, since the velocity is not calculated until the edge of the pulse is acquired, only coarse velocity information can be obtained. However, in the present invention, not only the time when the edge is acquired but also the previous time. Since the speed is also calculated in the speed estimation section, fine speed information can be obtained. As a result, the speed information obtained in the speed estimation section can be reflected in the feedback control. That is, in the speed estimation section, the control unit 18 multiplies the estimated speed of the motor by the gear ratio to obtain the aforementioned door tip speed, compares the door tip speed with the target speed Vref, and determines that the door tip speed is the target speed. When it is slower than Vref, the speed of the motor 4 is controlled so that the door tip speed increases to the target speed Vref, and when the door tip speed is faster than the target speed Vref, the door tip speed decreases to the target speed Vref. The speed of the motor 4 is controlled.

  Therefore, the rear door 2 approaches the fully open position, the tip speed enters a deceleration state (section X3 in FIG. 3), and the time until the speed of the motor 4 gradually decreases and the next pulse edge is acquired becomes longer. Even in this case, feedback control can be performed using the estimated speed calculated in the speed estimation section, so that the tip speed of the rear door 2 can be smoothly and accurately controlled. Further, even if the motor 4 stops in the middle due to a heavy load on the motor 4 and a pulse edge cannot be acquired, the speed estimation calculation is continued and feedback control can be performed, so the motor 4 is driven. The rear door 2 can be opened to the end.

FIG. 7 is a flowchart showing the speed calculation procedure, where (a) shows processing executed at a sampling period of 5 ms, and (b) shows interrupt processing when a pulse edge is detected. In FIG. 7A, first, 1 is added to the counter value C _5m of the period counter (step S1). The period counter is provided in a predetermined area of the memory 19 in FIG. Next, an elapsed time T _0m after obtaining the previous edge is calculated (step S2). The elapsed time T _0m is obtained by multiplying the counter value C _5m of the period counter by the sampling period of 5 ms. T ₀₁ , T ₀₂ , T _{03 in} FIG. 5B correspond to the elapsed time T _0m here. Then, the calculated elapsed time is compared with T _{0 m} the previous edge period T _i, the elapsed time T _{0 m} determines whether exceeds a previous edge period T _i (step S3).

A result of the determination in step S3, if the elapsed time _{T 0 m} is I exceeds the previous edge period _{T i} (step S3: YES), the motor speed V to calculate as V = 1 _{/ T 0m} (step S4), and the door The tip speed Va is calculated by Va = 1 / T _0m × G (G is a gear ratio) (step S5). Here, the gear ratio G is a parameter for converting the speed of the motor 4 to the tip speed of the rear door 2, and takes different values depending on the door opening. This gear ratio G is stored in the memory 19. On the other hand, if the elapsed time T _0m does not exceed the previous edge period T _i as a result of the determination in step S3 (step S3: NO), the motor speed V is calculated as V = 1 / T _i (step S6). The door tip speed Va is calculated by Va = 1 / T _i × G (step S7).

When the edge of the pulse is detected by the edge detection unit 16, the process proceeds to the interrupt processing of FIG. 7B at that time, and the pulse period (time from edge to edge) determined by the edge detection is a new previous time. The edge period T _i is stored in the memory 19 (step S8). Then, after the interruption process is completed, the routine returns to the steady routine of FIG. 7A, and the door tip speed Va is calculated for each sampling. At this time, the previous edge period T _i in step S3 is updated to the new previous edge cycle stored in the memory 19 at step S8.

The above is an example in the case where the motor 4 is in a decelerating state (section X3 in FIG. 3) when the rear door 2 is opened, but the motor 4 is in a decelerating state (section X1 in FIG. 3) when the rear door 2 is closed. In this case, the speed control is performed based on the same principle. In the section where the motor 4 is in the acceleration or constant speed state, the speed control can be performed by the same method as the conventional method. Whether the motor 4 is in a decelerating state can be determined by any of the following.
(1) When the current target speed Vref is decreasing with respect to the past target speed Vref, it is determined that the vehicle is in a decelerating state.
(2) When the measured speed of the motor 4 is reduced with respect to the speed of the motor 4 measured in the past, it is determined that the motor 4 is in a decelerating state.
The present invention is particularly effective in the deceleration section (X3 or X1) in which the motor 4 is in the deceleration state and the pulse edge interval becomes long as described above. However, the speed control process described above is performed in the entire section of FIG. You may carry out over X1-X3.

  FIG. 8 is a block diagram showing an embodiment when the present invention is applied to pinching detection. Reference numeral 21 denotes a window opening / closing switch for instructing opening / closing of a vehicle window, which is provided in the driver's seat. Reference numeral 22 denotes a motor drive circuit for supplying current to the window opening / closing motor 23 to rotate the motor 23, and reference numeral 24 denotes a rotary encoder that generates a pulse in accordance with the rotation of the motor 23. Reference numeral 25 denotes a pulse detection circuit that detects a pulse output from the rotary encoder 24, and reference numeral 26 denotes an edge detection unit that detects edges (rising and falling) of the pulse detected by the pulse detection circuit 25. Reference numeral 27 denotes a speed calculation unit that calculates the speed V of the motor 23 based on the edge detected by the edge detection unit 26. Reference numeral 28 denotes a fluctuation amount calculation unit that calculates a speed fluctuation amount (difference between the current speed and a speed before a predetermined time) ΔV based on the speed calculated by the speed calculation unit 27. Reference numeral 29 denotes a control unit that controls the speed of the motor 23, and reference numeral 30 denotes a memory including a ROM, a RAM, and the like. The memory 30 stores in advance a sandwiching threshold value K described later.

  In the above, the speed control device 60 of the motor 23 is configured by the edge detection unit 26, the speed calculation unit 27, the fluctuation amount calculation unit 28, the control unit 29, and the memory 30. The functions of the edge detection unit 26, the speed calculation unit 27, the fluctuation amount calculation unit 28, and the control unit 29 can be realized by a microcomputer. Here, the edge detection unit 26 constitutes an embodiment of the detection means in the present invention, the speed calculation unit 27 constitutes an embodiment of the speed detection means in the present invention, and the fluctuation amount calculation unit 28 represents the fluctuation in the present invention. One embodiment of the amount calculating means is configured, the control unit 29 constitutes one embodiment of the controlling means in the present invention, and the memory 30 constitutes one embodiment of the storing means in the present invention.

Next, details of pinching detection will be described with reference to FIGS. FIG. 9 is a time chart showing the pinching detection method in comparison between the conventional method and the present invention. t represents a sampling period (for example, 5 ms). Conventionally, pinching is detected at sampling points a, d, and h when the edges E1, E2, and E3 of the pulse are acquired. That is, when a the edge E1 has been acquired, the pulse period T ₀ was determined as the motor period T, calculates a motor speed 1 / T _0. Then, at the point d where the edge E2 has been acquired, the pulse period T ₁ which confirmed the motor period T, calculates a motor speed 1 / T _1. Furthermore, when h edge E3 is obtained, the pulse period T ₂ which finalized the motor period T, calculates a motor speed 1 / T _2. In this way, the motor speed is calculated at each sampling time point when the edge is acquired, and the fluctuation amount of the motor speed is obtained each time. Then, it is determined whether or not the fluctuation amount (decrease amount) exceeds a predetermined threshold value. When the fluctuation amount exceeds the threshold value, it is determined that foreign matter is caught.

  In the conventional method described above, the pinching detection is performed only at the edge acquisition timings a, d, and h. Therefore, when the speed of the motor 23 is reduced due to the pinching of the foreign object, it takes time to acquire the next edge. However, the timing for detecting pinching is delayed. As a result, for example, a heavy load is applied to an arm or a neck sandwiched between windows, which may lead to a dangerous state. In order to avoid this, there is a method of detecting the pinching by detecting the current flowing through the motor 23. In this case, however, there is a problem that a current detection device is required and the cost is increased.

On the other hand, in the case of the present invention, as shown in FIG. 9, not only the edge acquisition timings a, d, and h but also the pinching detection at each sampling time point b, c, e, f, and g between them. Do. That is, at the time point a at which the edge E1 is acquired, the motor speed 1 / T ₀ is calculated using the determined pulse period T ₀ as the motor period T, as in the conventional case. At the next sampling time point b, no edge is acquired. Regardless of whether or not the edge is acquired, the motor cycle T is set to T = t based on the elapsed time t from the previous edge acquisition time point a, and the motor speed 1 / t. Is calculated. This motor speed is not an actual speed calculated from the determined pulse period but an estimated speed calculated based on the elapsed time t. An edge is not acquired at the next sampling time point c. In this case, the motor cycle T is set to T = 2t based on the elapsed time 2t from the previous edge acquisition time point a regardless of whether or not the edge is acquired, and the motor speed ( (Estimated speed) 1 / 2t is calculated.

The acquired next sampling time point d the edge E2, the pulse period T ₁ is determined, the pulse period T ₁ and a motor period T, calculates a motor speed (actual speed) ₁ / T 1. At the next sampling time e, no edge is acquired. Regardless of whether or not the edge is acquired, the motor cycle T is set to T = t based on the elapsed time t from the previous edge acquisition time d, and the motor speed (estimated speed). ) 1 / t is calculated. Thereafter, similarly, at the sampling times f and g, based on the elapsed time from the previous edge acquisition time d, the motor cycles T are set to T = 2t and T = 3t, respectively, and the motor speed (estimated speed) 1 / 2t, 1 / 3t is calculated. When the edge E3 in the sampling time h is obtained, based on the pulse period _{T 2} which finalized, the motor cycle T and T = _{T 2,} and calculates the motor speed (actual speed) 1 / _{T 2.}

In this way, the motor speed is calculated at all sampling points, and the fluctuation amount of the motor speed is obtained each time. This fluctuation amount is calculated as the difference between the motor speed obtained from the current motor cycle and the motor speed obtained from the previous pulse cycle (previous edge cycle). For example, at the sampling time point c, the fluctuation amount of the motor speed is calculated as (1 / 2t) − (1 / T ₀ ). Then, at each sampling, it is determined whether or not the fluctuation amount (decrease amount) exceeds a predetermined threshold value, and if the threshold value is exceeded, it is determined that there has been pinching. When the pinching is detected, the control unit 29 gives a command to the motor drive circuit 22 to stop the motor 23 and then control to reversely drive. As a result, the window is opened, and the foreign object is released.

  According to the pinching detection method as described above, at each sampling time from when the previous edge is acquired until the next edge is acquired, the motor is estimated according to the elapsed time from the acquisition time of the previous edge. Since the speed is calculated and the estimated speed variation is calculated based on this, if the motor speed drops due to the foreign object being caught, it becomes possible to detect the jamming until the next edge is acquired. Compared with the conventional case in which pinching detection is performed after acquisition, pinching can be detected at an earlier stage. In addition, even when the motor stops due to the rigid body being caught and the edge of the pulse cannot be detected, the estimated fluctuation amount is calculated, so that the jamming can be detected.

  FIG. 10 is a time chart showing the timing of pinching detection. As shown in the figure, even if it takes time until the next pulse edge E occurs after the motor speed decreases, in the present invention, the motor speed is obtained at a constant time interval until the next edge E, and the speed fluctuation amount is obtained. Since the (decrease amount) is calculated, entrapment is detected at the time ta when the speed fluctuation amount exceeds the entrapment threshold K. On the other hand, in the conventional case, the speed fluctuation amount is calculated at time tb after the occurrence of the edge E, and pinching is detected. Therefore, the present invention can detect the pinching at a timing earlier than that of the prior art. As a result, in the present invention, for example, when an arm, a neck, or the like is caught in a window, the pinching is detected immediately, and the motor is stopped. It can be avoided. In addition, since no current detection device is required, there is no problem of increased cost.

  FIG. 11 is a flowchart showing a procedure for detecting pinching, and shows processing executed at a sampling period of 5 ms. First, it is determined whether or not an edge of a pulse has been acquired (step S11). When the edge is acquired (step S11: YES), the motor speed V is calculated based on the previous edge period Ti (step S16). The motor speed V immediately after the edge acquisition is calculated by V = 1 / Ti. Next, a speed fluctuation amount ΔV is calculated from the motor speed V and the previous edge period Ti (step S17). The speed fluctuation amount ΔV immediately after the edge acquisition is ΔV = 1 / Ti−1 / Ti = 0.

On the other hand, when the edge is not acquired (step S11: NO), 1 is added to the counter value C _5m of the period counter (step S12). The period counter is provided in a predetermined area of the memory 30 in FIG. Next, an elapsed time T _0m after obtaining the previous edge is calculated (step S13). The elapsed time T _0m is obtained by multiplying the counter value C _5m of the period counter by the sampling period of 5 ms. In FIG. 9, T = t, T = 2t, and T = 3t correspond to the elapsed time T _0m here. Subsequently, based on the elapsed time _T0m , the motor speed (estimated speed) V is calculated as V = 1 / _T0m (step S14). Further, the speed fluctuation amount (estimated fluctuation amount) ΔV is calculated as ΔV = 1 / T _0m −1 / Ti from the motor speed V and the previous edge period Ti (step S15).

  After execution of steps S15 and S17, the process proceeds to step S18, where the calculated speed fluctuation amount ΔV is compared with the sandwiching threshold value K. If ΔV> K as a result of the comparison (step S18: YES), it is determined that there has been pinching and a pinching detection signal is output (step S19). As a result of comparison, if ΔV> K is not satisfied (step S18: NO), it is determined that there is no pinching, and the process ends without executing step S19.

  In the above-described embodiment, an example in which the present invention is applied to a rear door opening / closing device and a pinch detection device in a vehicle has been described. However, the present invention is not limited to this and can be applied to all devices that control the speed of a motor. .

It is a schematic mechanism diagram of a rear door opening and closing device of a vehicle to which the present invention is applied. It is a block diagram which shows the electrical structure of a rear door opening / closing apparatus. It is a figure which shows the target speed memorize | stored in memory. It is a figure which shows the control system in feedback control. It is a figure explaining the detail of the speed control of a motor. It is a figure explaining the speed control of the conventional motor. It is a flowchart which shows the procedure of speed calculation. It is a block diagram which shows other embodiment of this invention. It is a time chart explaining the detection method of pinching. It is a time chart which shows the timing of pinching detection. It is a flowchart which shows the procedure of pinching detection.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Vehicle 2 Rear door 4 Motor 13 Motor drive circuit 14 Rotary encoder 15 Pulse detection circuit 16 Edge detection part 17 Speed calculation part 18 Control part 19 Memory 22 Motor drive circuit 23 Motor 24 Rotary encoder 25 Pulse detection circuit 26 Edge detection part 27 Speed Calculation unit 28 Fluctuation amount calculation unit 29 Control unit 30 Memory 50 Speed control device 60 Speed control device Vref Target value K Clamping threshold E0, E1, E2, E3 Pulse period T ₀ , T ₁ , T ₂ Pulse period (previous Edge period)
V Motor speed ΔV Speed fluctuation amount

Claims (5)

Detecting means for detecting an edge of a pulse generated by rotation of the motor;
Speed calculating means for calculating the speed of the motor based on the edge of the pulse detected by the detecting means;
Control means for comparing the speed calculated by the speed calculation means with a predetermined target value and controlling the motor so that the speed becomes a target value;
In a motor speed control device comprising:
The speed calculation means, when the next edge is not acquired within a predetermined time after the previous edge of the pulse is acquired, until the next edge is acquired at a predetermined timing. Calculate the estimated speed according to the elapsed time from the acquisition time,
The speed control device for a motor characterized in that the control means controls the speed of the motor based on the estimated speed and a target value in a section from when the predetermined time has elapsed until the next edge is acquired. . In the motor speed control apparatus according to claim 1,
The motor speed control device according to claim 1, wherein the predetermined time is a previous edge period representing a time between a previous edge and an edge immediately before the previous edge. The motor speed control device according to claim 2,
The speed calculation means calculates the speed of the motor at a constant sampling period, calculates the speed based on the previous edge period for each sampling until the predetermined time is reached after the previous edge is acquired, A speed control of a motor, characterized in that the estimated speed is calculated based on the time from the acquisition time of the previous edge to each sampling time until the next edge is acquired after a predetermined time has elapsed. apparatus. A device that controls the speed of the motor for opening and closing the rear door of the vehicle in multiple stages of acceleration, constant speed, and deceleration,
Storage means for storing a target value of a predetermined speed corresponding to each of the plurality of stages;
Detecting means for detecting an edge of a pulse generated by rotation of the motor;
Speed calculating means for calculating the speed of the motor based on the edge of the pulse detected by the detecting means;
The tip speed of the rear door corresponding to the motor speed calculated by the speed calculation means is compared with a predetermined target value stored in the storage means so that the tip speed becomes the target value. Control means for controlling the motor;
In a motor speed control device comprising:
The speed calculation unit is configured to acquire a next edge when the motor is in a deceleration state and the next edge is not acquired within a predetermined time after the previous edge of the pulse is acquired. Meanwhile, at a predetermined timing, calculate the estimated speed according to the elapsed time from the previous edge acquisition time,
The speed control device for a motor characterized in that the control means controls the speed of the motor based on the estimated speed and a target value in a section from when the predetermined time has elapsed until the next edge is acquired. . A device for controlling the speed of a motor for driving the opening and closing body and detecting that a foreign object has been caught in the opening and closing body,
Storage means for storing a threshold for detecting pinching;
Detecting means for detecting an edge of a pulse generated by rotation of the motor;
Speed calculating means for calculating the speed of the motor based on the edge of the pulse detected by the detecting means;
A fluctuation amount calculating means for calculating a fluctuation amount of the motor speed calculated by the speed calculating means;
The speed fluctuation amount calculated by the fluctuation amount calculating means is compared with a threshold value stored in the storage means, and when it is detected that a foreign object is caught in the opening / closing body based on the comparison result, Control means for controlling the motor to stop;
In a motor speed control device comprising:
The speed calculation means calculates an estimated speed according to an elapsed time from the acquisition time of the previous edge at a predetermined timing after the previous edge of the pulse is acquired until the next edge is acquired. And
The fluctuation amount calculating means calculates an estimated fluctuation amount of the motor speed based on the estimated speed calculated by the speed calculating means,
The motor speed control device according to claim 1, wherein the control means detects the trapping of a foreign substance based on the estimated fluctuation amount and a threshold value and stops the motor.

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