JP2019193450A - Load detector of dynamo-electric machine - Google Patents

Abstract

To provide a load detector of a dynamo-electric machine which allows for high accuracy detection of a load with no impact of ripple noise.SOLUTION: A pulse signal P synchronizing with rotation of the motor shaft is outputted from a pulse detector. A current change measurement unit measures variation of the current value, by comparing the current values of the same physical relationship during one rotation, e.g., the current values of the same rising timing during one rotation. In particular, variation ΔI1 of a current value is measured by comparing the current value at a rising timing matching the starting point of the first unit pulse signal P1 and the current value at a rising timing matching the starting point of the second unit pulse signal P2. The load per rotation of a motor is calculated by a load detection unit.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a load detection device for a rotating electrical machine.

  Patent Document 1 discloses a technique for detecting pinching by a door glass in a vehicle power window device that opens and closes the door glass by an actuator that uses a motor as a power source as a representative example of a rotating electrical machine. As a method for detecting the pinching, various methods have been proposed in addition to the conventional pulse detection method and the method using torque-current characteristics according to Patent Document 1. A method is also conceivable in which a pulse signal synchronized with the rotation of the motor is monitored, the current of the drive voltage and the current value is measured, the motor load is calculated using a predetermined calculation formula, and this is compared with a threshold value.

JP 2005-133449 A

  When a DC motor is used as a power source, current pulsation occurs due to the influence of ripple noise due to its structure. If the current change due to ripple noise is in the amperage order, the measured current value will vary greatly, and the motor load cannot be detected accurately.

  The present invention has been made paying attention to such problems, and an object of the present invention is to provide a load detection device for a rotating electrical machine that enables highly accurate detection of a load without being affected by ripple noise. There is.

  A load detection device for a rotating electrical machine that solves the above-described problem is a pulse output unit that outputs a pulse signal synchronized with the rotation of a rotating shaft, and a positional relationship during one rotation based on the pulse signal output from the pulse output unit. Current change measuring means for measuring the amount of change in the current value by comparing the same current values, and a load for calculating the load of the rotating electrical machine using the amount of change in the current value measured by the current change measuring means Detecting means.

  According to this configuration, by comparing the current values having the same positional relationship during one rotation, it is possible to measure the amount of change in the current value without being affected by the current change due to the ripple noise. And it becomes possible to calculate correctly the load of a rotary electric machine using the variation | change_quantity of the measured current value. Therefore, the load can be detected with high accuracy without being affected by the ripple noise.

  With respect to the load detection device for a rotating electric machine, the pulse output means includes a high level period from the first rising to the falling for each rotation of the rotating shaft, and a continuous period from the falling to the next. A unit pulse signal having one low level period until the rising edge and one cycle is output, and the current change measuring means determines the rising or falling edge during one rotation based on the two unit pulse signals. It is good also as comparing the current values with the same timing.

  According to this configuration, the current comparison timing can be easily grasped by comparing the current values at the rising edges or the falling edges of the pulse edges.

  According to the present invention, a load can be detected with high accuracy without being affected by ripple noise.

The schematic block diagram of a power window apparatus. The block diagram of a power window apparatus. The conceptual diagram of the load detection method by a comparative example. The conceptual diagram of the load detection method by this example.

Hereinafter, an embodiment of a load detection apparatus for a rotating electrical machine will be described.
As shown in FIG. 1, a power window device 1 which is an application example of a load detection device for a rotating electrical machine uses a movable window glass 3 provided on a door 2 on the side of a vehicle as a motor that is a typical example of a rotating electrical machine. Among them, for example, it is automatically opened and closed by an actuator 4 using a DC motor as a power source. The window glass 3 moves up and down in a sliding direction D that coincides with a substantially vertical direction, and opens and closes the opening 6 of the door frame 5 by a closing operation by raising and an opening operation by lowering. The window glass 3 is an example of an opening / closing body.

  As shown in FIG. 2, the power window device 1 includes an operation unit 11 that is operated by an occupant in addition to a controller 10 that controls opening and closing of the window glass 3. The controller 10 opens and closes the window glass 3 by supplying power from the battery 8 to the actuator 4 while controlling the drive circuit 7 based on an operation signal input from the operation unit 11.

  In addition to the pulse detector 12, a voltage detector 13 and a current detector 14 are electrically connected to the controller 10. The pulse detector 12 outputs a pulse signal P synchronized with the rotation of the motor shaft (rotary shaft) of the DC motor in the actuator 4. The pulse signal P is an electric signal in which unit pulse signals using rectangular waves are continuously generated. The pulse detection unit 12 has one high level period from the first rise to the fall and one low level period from the fall to the next rise that follows the high level period per rotation of the motor shaft. Each unit pulse signal having one cycle is output. The pulse detector 12 corresponds to pulse output means.

  The controller 10 recognizes the position of the window glass 3 by counting the number of pulse edges of the pulse signal P (for example, the sum of the number of rising edges and the number of falling edges). That is, on the assumption that the moving distance of the window glass 3 per one high level period or low level period is defined, for example, the count value of the fully open position of the window glass 3 is set to “0”, and the number of pulse edges Is counted, the position of the window glass 3 can be recognized from the fully opened position.

  The voltage detector 13 detects the drive voltage V of power supplied from the drive circuit 7 to the actuator 4 through the power supply path Rp, and the current detector 14 supplies power supplied from the drive circuit 7 to the actuator 4 through the power supply path Rp. The drive current I is detected.

  The controller 10 monitors the drive voltage V by the voltage detection unit 13 and the drive current I by the current detection unit 14 in addition to the pulse signal P by the pulse detection unit 12 and is created from the following basic formula according to the law of energy conservation. The ascending load of the window glass 3 is calculated using the following calculation formula, and it is compared with a threshold value to detect the object sandwiched by the window glass 3.

First, the electric energy W [J] is represented by the basic formula (1), and the work W [J] is represented by the basic formula (2).
Electric power amount W [J] = Power P [W] × Time t [s] (1)
Work W [J] = force F [N] × distance moved in the direction of force d [m] (2)
Then, according to the law of conservation of energy, the magnitude F [N] of the force is solved on the assumption that the electric energy W [J] of the basic formula (1) and the work W [J] of the basic formula (2) are equal. And the rising load [N] of the window glass 3 can be expressed by the following formula (3).

Ascent load [N] of window glass 3 = drive voltage V [V] × drive current I [A] × movement time t [s] of window glass 3 per unit pulse signal / movement of window glass 3 per unit pulse signal Distance d [m] (3)
That is, on the premise that the moving distance d [m] of the window glass 3 per unit pulse signal is defined, the driving voltage V [V] and the driving current I [A] and the window glass 3 per unit pulse signal By monitoring the movement time t [s], the rising load [N] of the window glass 3 can be calculated. When the object is sandwiched in the window glass 3, a threshold value that takes into consideration that the rising load [N] of the window glass 3 is larger than that in the case where the object is not sandwiched in the window glass 3 is defined. On the assumption that the window glass 3 is in the rising load [N], it is possible to detect the object sandwiched by the window glass 3 by comparing it with the threshold value.

  When the ascending load [N] of the window glass 3 becomes equal to or greater than the threshold value, the controller 10 turns the window glass 3 in the reverse direction or stops it, assuming that an object is caught by the window glass 3.

  Note that the rising load [N] of the window glass 3 is increased not only when an object is sandwiched between the window glass 3 but also when the window glass 3 moves near the closed position. This is because when the window glass 3 moves in the vicinity of the closing position, sliding resistance is generated by sliding the upper part of the window glass 3 in the glass run. If the window glass 3 reaches the contact position with the glass run and the object is sandwiched by the window glass 3 and the window glass 3 is reversed, the window glass 3 cannot be closed. In other words, so-called erroneous inversion occurs.

  Therefore, in order to prevent erroneous reversal, a dead zone in which pinching detection is invalidated is set in the vicinity of the closed position, and when the rising load [N] of the window glass 3 exceeds the threshold in the dead zone area The window glass 3 is closed until it reaches the closed position without determining that the object is caught by the window glass 3. Thereby, the window glass 3 can be closed completely.

  By the way, when a DC motor is used as a power source, due to its structure, current pulsation occurs due to the influence of ripple noise, and thus the drive current I by the current detector 14 varies greatly.

  Therefore, the controller 10 compares the current values having the same positional relationship during one rotation based on the pulse signal P output from the pulse detection unit 12, thereby measuring the change amount of the current value. 15 and a load detection unit 16 that calculates a load per one rotation of the motor using the amount of change in the current value measured by the current change measurement unit 15. The current change measurement unit 15 corresponds to a current change measurement unit, and the load detection unit 16 corresponds to a load detection unit.

Next, the operation of the power window device 1 will be described.
As shown in FIG. 3, in the comparative example for this example, the current value at the rise timing of the pulse signal P by the pulse edge E1 is compared with the current value of the fall timing by the next pulse edge E2. In this comparative example, the current value of the pulse edge E1 and the current value of the pulse edge E2 are the same value. When the change amount zero of the current value at this time is applied to the drive current I of the above equation (3), the window It is understood that the load of the motor according to the rising load [N] of the glass 3 becomes zero and the load cannot be detected. That is, since the motor has ripple noise, there is a case where there is no change in current even if the current is compared at the pulse edge, and the load cannot be detected. Incidentally, when the current value at the fall timing due to the pulse edge E2 is compared with the current value at the rise timing due to the next pulse edge E3, a change amount ΔI of the current value is obtained. Accordingly, the motor load can be detected.

  On the other hand, in this example shown in FIG. 4, the current change measurement unit 15 compares current values having the same positional relationship during one rotation, for example, current values having the same rising timing during one rotation. Then, the amount of change in the current value is measured. Specifically, the current value at the rise timing that coincides with the start point of the first unit pulse signal P1 is compared with the current value at the rise timing that coincides with the start point of the second unit pulse signal P2. Thus, the amount of change ΔI1 in the current value is measured. Then, the load detection unit 16 calculates the load per one rotation of the motor according to the above equation (3). That is, by comparing the current values under the same positional relationship between the motor shaft and the motor coil, the load can be detected without being affected by ripple noise. Incidentally, when the current value at the rise timing that coincides with the start point of the second unit pulse signal P2 is compared with the current value at the rise timing that coincides with the start point of the third unit pulse signal, the current value of Since the change amount ΔI2 is obtained, the load per one rotation of the motor can be detected according to the above equation (3) as described above.

As described above, according to the present embodiment, the following effects can be obtained.
(1) By comparing current values having the same positional relationship during one rotation, it is possible to measure the amount of change in the current value without being affected by the current change due to ripple noise. Then, it is possible to correctly calculate the load per one rotation of the motor using the measured change amount of the current value. Therefore, the load can be detected with high accuracy without being affected by ripple noise.

(2) The current comparison timing can be easily grasped by comparing the current values at the rising edges of the pulse edges.
(3) Since the load can be detected with high accuracy, it is not necessary to give a large width to the threshold for detecting pinching. As a result, it is possible to contribute to a reduction in the load for pinching detection.

In addition, the said embodiment can also be changed and actualized as follows.
-It may replace with the composition which compares current values with the same rise timing in one rotation, and may adopt the composition which compares current values with the same fall timing in one rotation. According to this configuration, the current comparison timing can be easily grasped by comparing the current values at the falling edges of the pulse edges.

  In general, the pulse detector 12 includes two Hall ICs (an example of pulse output means) so that the position of the window glass 3 can be recognized and the moving direction of the window glass 3 can be detected. Here, based on the pulse signal P output from any Hall IC, current values having the same positional relationship during one rotation may be compared.

  Instead of the configuration for detecting the load per motor rotation, a configuration for detecting the load per motor rotation or three rotations may be adopted, for example. Alternatively, a configuration may be adopted in which current values having the same positional relationship during one rotation are compared based on two unit pulse signals that are spaced apart from each other and that have one or more unit pulse signals in between.

The present invention may be applied not only to the power window device 1 but also to a device using a DC motor as a power source, such as an electric wiper device or an electric mirror device.
The present invention may be embodied in a drive device for an opening / closing body that performs an opening operation by raising and a closing operation by lowering using a motor as a power source, such as a shutter of a building.

The present invention may be embodied in a driving device for an opening / closing body that is operated in the horizontal direction using a motor as a power source, such as a sliding door of a vehicle or an automatic door of a building.
The present invention may be embodied in a driving device for an opening / closing body that is opened / closed using a motor as a power source, such as a sunroof of a vehicle.

  The present invention may be applied to a load detection device for a rotating electrical machine such as a stepping motor, an AC motor, or a generator, instead of the DC motor load detection device that is easily affected by ripple noise.

  DESCRIPTION OF SYMBOLS 1 ... Power window apparatus (load detection apparatus of a rotary electric machine), 2 ... Door, 3 ... Window glass, 4 ... Actuator, 5 ... Door frame, 6 ... Opening part, 7 ... Drive circuit, 8 ... Battery, 10 ... Controller, DESCRIPTION OF SYMBOLS 11 ... Operation part, 12 ... Pulse detection part (pulse output means), 13 ... Voltage detection part, 14 ... Current detection part, 15 ... Current change measurement part (current change measurement means), 16 ... Load detection part (load detection means) ).

Claims (2)

Pulse output means for outputting a pulse signal synchronized with the rotation of the rotary shaft;
Based on the pulse signal output from the pulse output means, current change measuring means for measuring the amount of change in the current value by comparing current values having the same positional relationship during one rotation;
A load detecting device for a rotating electrical machine, comprising: load detecting means for calculating a load of the rotating electrical machine using a change amount of the current value measured by the current change measuring means. The pulse output means includes a high level period from the first rise to the fall and a low level period from the fall to the next rise that follows the high level period per rotation of the rotating shaft. Unit pulse signal that has one period and makes one cycle,
The load detection device for a rotating electrical machine according to claim 1, wherein the current change measuring means compares current values having the same rising or falling timing during one rotation based on two unit pulse signals.