JP2541229B2 - Entrapment detection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of use] The present invention relates to an entrapment detection device, and more particularly, to an entrapment detection device based on the load of a motor that drives a driven body.

[Prior Art] Conventionally, various types of devices have been proposed that detect a foreign object caught by a driven body driven by a motor as a drive source, for example, vehicle window glass. In such a device, it is difficult to actually measure the drive torque of the driven body with a simple configuration, and therefore the pinch detection is performed based on a predetermined parameter of the motor that drives the driven body. For example, assume that the load of a DC motor is estimated by its drive current, and the reference current of a preset value that will flow to the DC motor according to the position of the driven body is compared with the actual drive current. , The trapping is detected. In this case, since the starting current immediately after starting the motor is considerably larger than the steady-state current, a time limiter is provided to prevent pinch detection for a certain period after starting the motor so that erroneous detection does not occur due to this starting current. Has been proposed (eg
"Drive device for overload protection of motor" described in JP-A-59-172924).

[Problems to be Solved by the Invention] However, such a detection device has a problem that entrapment cannot be detected while the time means is operating. Therefore, if a pinch occurs immediately after driving the motor, it cannot be detected for a certain period of time, and the safety of the mechanism for driving the driven body cannot be sufficient.

This period required for avoiding erroneous detection (the period during which the entrapment detection is not performed) is performed by the device that performs the entrapment detection by estimating the actual load using the motor characteristics from the motor parameters. Needed in shape,
The problem is not limited to estimating the load using the drive current of the DC motor as a parameter.

The present invention has been made for the purpose of solving the above problems and accurately detecting entrapment.

Configuration of the Invention The configuration of the present invention that achieves the above object will be described below.

[Means for Solving Problems] The pinching detection device of the present invention is, as illustrated in FIG. 1, a reference value setting means for obtaining a load reference value at the time of normal driving of the motor M2 for driving the driven body M1. M3, from the parameters of the motor M2, based on the characteristics of the motor M2, the actual load estimation means M4 for estimating the actual load of the motor M2, the calculated load reference value and the detected actual load Comparing the above, in the pinch detection device provided with the pinch detection means M5 for detecting the pinch by the driven body M1, the reference value setting means M3 is a position detection means for detecting the open / closed position of the driven body M1. M6
A virtual load estimating means M7 for estimating the load applied to the motor M2 according to the detected opening / closing position of the driven body M1, and an elapsed time detecting means for detecting the passage of time after the motor M2 is started. M8, and a calculation means M9 for calculating the load reference value based on the detected elapsed time and the estimated virtual load.

Here, the driven body M1 may be any object as long as it can detect entrapment, but various objects such as a window glass in a vehicle power window, an electric shutter, and an automatic door can be considered. Also the motor
M2 includes not only a DC motor but an AC motor and the like.

The actual load estimating means M4 may be, for example, one that detects a parameter of the motor M2, for example, an armature current of a DC motor, and estimates the load based on the characteristics of the motor M2. Instead of using a so-called torque meter, a motor
Any one may be used as long as it estimates the actual load of the motor M2 based on the characteristics of the motor M2 from one or several of the current and voltage of M2, the number of revolutions, and the like.

The entrapment detection means M5 may be realized by a discrete configuration using a comparator or the like, or may be configured as an arithmetic logic operation circuit together with the reference value setting means M3 and the like.

The reference value setting means M3 includes a position detecting means M6, a virtual load estimating means M7, an elapsed time detecting means M8, and a calculating means M9, and obtains a load reference value when the driven body M1 is normally driven. The position detection means M6 may be configured as a sensor that directly detects the position of the driven body M1, or is configured to indirectly detect the position by an encoder or the like that measures the rotation angle and the number of rotations of the motor M2. May be. The virtual load estimation means M7 is means for estimating the load according to the position of the driven body M1, and for example, stores the relationship between the position of the driven body M1 and the motor load in a storage means in advance, and drives the driven body. A configuration or the like can be considered in which the reference load is estimated by referring to this storage means based on the position of the body M1. Of course, if the mechanism for driving the driven body M1 has a load uniquely determined by the position of the driven body M1, the reference virtual load may be estimated based on such a relationship.

The elapsed time detection means M8 is for detecting the passage of time after the motor M2 is started, and may be, for example, one that measures time in a certain unit (millisecond or the like), or notifies this when a predetermined time has passed. You can do it. Calculation means M9
Is for calculating the load reference value based on the elapsed time and the virtual load, and may be configured to calculate the load reference value by correcting the virtual load according to the time from the start of the motor M2. The load reference value based on the virtual load may be simply changed before and after the passage.

[Operation] The pinch detection device of the present invention having the above configuration estimates the pinch of the driven body M1 driven by the motor M2 by the load reference value set by the reference value setting means M3 and the actual load estimation means M4. The detected actual load of the motor is detected by comparing with the pinch detection means M5. Moreover, the entrapment detection device of the present invention sets the load reference value as follows. That is, based on the position of the driven body M1 detected by the position detection means M6, the virtual load estimation means M7 estimates the load applied to the motor M2 corresponding to the position of the driven body M1 and is estimated. The load reference value is calculated by the calculating means M9 based on the virtual load and the elapsed time from the activation of the motor M2 detected by the elapsed time detecting means M8.

As a result, the load reference value used to detect the entrapment becomes a value that corresponds to the mode of estimation of the actual load that depends on the elapsed time since the motor M2 was started.

[Embodiment] In order to further clarify the configuration and operation of the present invention described above, a preferred embodiment of the entrapment detection device of the present invention will be described below. FIG. 2 is a block diagram showing the configuration of a window motor driving device equipped with an entrapment detection device as an embodiment of the present invention.

As shown in the figure, the window motor driving device drives a DC motor 1 that raises and lowers a window provided in a vehicle, and is provided at an easily operable location in the vehicle and operated by an occupant (hereinafter, referred to as an up-down switch). 2), a battery 3 as a power source of the DC motor 1, and an electronic control unit 4 that controls the DC motor 1 in response to an operation of the switch 2.

The electronic control unit 4 is composed of a well-known CPU5, ROM6, RAM7, backup RAM7a, timer 8 and the like as an arithmetic and logic operation circuit, and these elements are mutually connected via a bus 9 and further to the outside. Input / output port 10 for input / output of
Is also connected to. Switch 2 for I / O port 10
Connected to the buffer 11, two drive circuits 16 and 17 connected to each of the two relays 12 and 13, a rotation angle detection circuit 20 connected to the transformer 18, and a load detection connected to the current detection resistor 22. Circuit 25 is connected.

The switch 2 connected to the buffer 11 is of a momentary type, and is operated from a neutral position (normally open NO) to an up-up or down-down position by an occupant who wants to move the window up and down. Buffer 11
Converts the state of the switch 2 into an electric signal, and this signal is read by the CPU 5 via the input / output port 10.

The relays 12, 13 and the like connected to the drive circuits 16, 17 form a circuit for supplying an armature current for driving the DC motor 1. That is, the normally open contacts Nb of both relays 12 and 13 are connected to the positive side terminal of the battery 3, while the normally closed contacts Na of both relays 12 and 13 are the current detection resistor 22 and the transformer 18. It is connected to the grounded negative side terminal of the battery 3 via the primary side winding, and the common side Nc of the relays 12 and 13 is connected to the DC motor 1 respectively. Therefore, by the control signal from CPU5,
When the relays 12 and 13 are exclusively switched on,
Current flows in the direct current motor 1 in either the forward or reverse direction depending on the operating states of the relays 12 and 13, and the direct current motor 1 is driven in the forward or reverse direction.

Since the armature current of this DC motor 1 flows through the primary winding of the transformer 18, an induced voltage corresponding to the pulsation of the armature current is mutually induced on the secondary side of the transformer 18. The rotation angle detection circuit 20 shapes this waveform and outputs it as a pulse signal. Therefore, the CPU 5 detects the rotation of the DC motor 1 for each predetermined rotation angle from the number of segments of the commutator in contact with the brush of the DC motor 1 by reading the change in this signal via the input / output port 10. be able to.

The armature current flows through the current detection resistor 22 together with the primary winding of the transformer 18, and a potential difference according to the current value is generated across the resistor 22. The load detecting means 25 integrates this potential difference to obtain an average value, which is analog / digital converted and output. Therefore, by reading the output of the load detection circuit 25 via the input / output port 10, the armature current flowing through the DC motor 1 can be detected. The armature current can be regarded as a parameter that reflects the load when the DC motor 1 is driven in a steady state.

Next, the control executed by the window motor driving device having the above-described configuration will be described with reference to the flowchart in FIG. 3, and the operation as the pinch detection device will be described. When the window motor driving device is turned on, it executes a window control routine shown in FIG. 3, and first, at step 100, a so-called initialization process is performed. As the initialization processing, for example, the RAM 7 is cleared, or the value of the position counter Xc corresponding to the position X of the window at the time when the opening / closing is completed last time is backed up in the RAM 7a.
Read from the current counter Xc as an initial value and set to a predetermined address in RAM7, and also the virtual load HY determined by the position of the window until the previous learning value.
There are processes such as expansion to RAM7. The position counter Xc corresponding to the position X of the window is set to a value of 200 at the fully closed position of the window and a value of 0 at the fully opened position of the window.

After the initialization process is completed, the state of the up / down switch 2 is determined (step 110). When the switch 2 read via the buffer 11 is operated to the UP side, the relay 12 is turned on via the drive circuit 16 and the DC motor 1 is rotated to raise the window (step 120). ). Subsequently, the position X of the window is calculated from the value of the position counter Xc (step 130), and the load detection circuit 25 further detects the armature current flowing through the DC motor 1 to determine the actual load Y of the DC motor 1. Is estimated (step 140).

Then, the timer 8 is accessed to measure the elapsed time t after the DC motor 1 is started (step 150) and whether the elapsed time t exceeds a predetermined time T or not. A judgment is made (step 160). When the elapsed time t has not reached the predetermined time T, the load reference value HY used for detecting the entrapment is calculated from the position X of the window and the elapsed time t (step 170), while the predetermined time T has elapsed. Is the load reference value HY at the window position X
(Step 180). Therefore, the load reference value HY after the DC motor 1 is started is as shown in FIG.
It is a value that takes into consideration the starting current of the virtual load KY, and after the elapse of the predetermined time T, the virtual load KY that is previously determined according to the position of the window.
Is a value corresponding to (solid line J in FIG. 4).

After the processing of step 170 or 180 for setting the load reference value HY described above, it is determined whether the actual load Y estimated in step 140 exceeds the load reference value HY (step 190), and the actual load Y is determined. Is less than the load reference value HY,
A process of calculating a new load reference value HY (update process of the load reference value HY) is performed based on the actual load Y of the motor 1 and the load reference value HY (step 200). Such update processing of the load reference value HY is performed by the driving force required to move the window, in other words, the load of the DC motor 1, decreases the lubricating oil of the window drive system and deteriorates the packing provided on the window frame. It is performed for the purpose of learning the load reference value used for entrapment detection in accordance with this.

Then, pulse detection and window stop processing are performed as the window moves (step 210). That is,
The rotation angle detection circuit 20 determines whether or not the rotation angle pulse is input within a predetermined time Tout (step 21
2) If it is input, the counter Xc representing the position of the window is incremented by 1 (step 21
4) If the rotation angle pulse is not input even after the time Tout elapses and the value of the counter Xc is larger than the specific value XL indicating the window position close to the fully closed position where there is no possibility of pinching a finger etc. (step 215), the value 200 is set in the counter Xc (step 216) because the window has reached the fully closed position, and the relay 12 is turned off to stop the window (step 218).

On the other hand, if the estimated actual load Y of the DC motor 1 exceeds the load reference value HY, it can be determined that entrapment has occurred. Therefore, the process proceeds from step 190 to step 220 and thereafter, and the window width W After the process of lowering the load reference value is performed, the load reference value HY is updated (step 230) and the pulse detection and window stop process (step 240) is performed in the same manner as in step 200 and thereafter. It goes without saying that in the process of step 220 of lowering the window by the width W, the relay 12 is turned off and the relay 13 is turned on. In step 240 for detecting a pulse, the counter Xc is decremented by 1 each time a pulse is detected, and when the window is lowered by the width W or when no pulse is detected (that is, the fully opened position is reached). When the relay 13 is turned off, the window is stopped.

After the processing described above is finished, the processing of steps 110 to 240 is repeated again, but if the switch 2 is returned from the UP UP position to the OFF NO position while the window is rising, the determination in step 110 is made. Accordingly, the processing shifts to step 250, the relay 12 is turned off, and the movement of the window is stopped.

Next, the processing when the switch 2 is operated to the down DOWN position will be described. In this case, the processing shifts from step 110 to step 260 and thereafter, first the relay 13 is turned on, the DC motor 1 is rotated to lower the window (step 260), and the window position X is counted by the counter X.
Calculation is performed from the value of c (step 270), and pulse detection and window stop processing are further performed (step 280).
The process in step 280 is similar to that in step 210 or 240 described above, and if the pulse signal from the rotation angle detection circuit 20 is input within the predetermined time Tout, the value of the counter Xc is decremented and the input is completed. If not, the window is stopped assuming that the window has reached the fully open position.

The window motor drive device having the above-described configuration raises and lowers the window in accordance with the operation of the switch 2. In particular, the pinch detection device of the present embodiment incorporated in a part of the window motor drive detects the pinch of the window by the DC motor. The starting current of 1 is taken into consideration. As an example, as shown in FIG. 5, the window has a position Wa that is about 70 percent open.
Starts to move in the fully closed direction (this timing is time ta) and passes through position Wb (arrival time tb) to position Wc (arrival time
An example will be described in which the process is closed up to tc).

In this case, the load reference value HY used for trapping detection is a value determined by the position of the window (the virtual load shown in FIG. 5).
As shown in FIG. 4, if the virtual load KY is used between the start-up time ta and the predetermined time period T, the conventional device for KY) will erroneously detect that a pinching has occurred due to the start-up current. If entrapment detection is prohibited during the time T, entrapment immediately after the window rise cannot be detected.

On the other hand, in the pinch detection device of this embodiment, when the window starts moving from the position Wa, the timing
From ta to the predetermined time T, the load reference value HY is calculated based not only on the position of the window but also on the elapsed time t (see step 170 in FIG. 3). Therefore, start (time ta)
From the time tb to the time tb, the trapping can be detected using the load reference value HY that takes into account the starting current of the DC motor 1, and when the window stops from the time tb (time t
Until tc), the DC motor 1 is considered to be in a steady state,
Entrapment can be detected by using the value corresponding to the virtual load as the load reference value HY.

As a result, the trapping can be detected extremely accurately and from the fully closed position to the fully opened position of the window. That is, the problem of erroneous detection of entrapment based on an error when estimating the actual load of the motor from the armature current of the DC motor 1 can be sufficiently solved, and the entrapment can be accurately detected even immediately after starting.

Further, in the present embodiment, when the trapping is detected, the window is lowered by the predetermined width W, so that the trapped state can be immediately released, and the safety of the power window device is further ensured. I am trying. Further, in this embodiment, since the load reference value HY is learned when the window rises, it is possible to continue to perform accurate pinch detection by sufficiently responding to the load change due to the change with time of the device. Therefore, no labor such as adjustment is required.

Although the embodiment of the present invention has been described above, the present invention is not limited to such an embodiment. For example, a configuration in which the load reference value is determined by considering the elapsed time t even after the predetermined time T has elapsed, A configuration that includes an encoder that detects the position of the window, a limit switch, or the like, or a configuration that estimates the actual load of an AC motor or a stepping motor that drives the driven body using parameters such as armature current,
Needless to say, the present invention can be implemented in various modes without departing from the scope of the present invention.

EFFECTS OF THE INVENTION As described in detail above, according to the entrapment detection device of the present invention, without increasing the parameters of the motor to be detected,
Even when the motor for driving the driven body is started, the pinching can be detected with high accuracy. Therefore, the trapping can be detected immediately after the motor is started, and the problem of erroneous detection can be avoided.

As a result, by using the trapping detection device of the present invention, the safety of the device can be further ensured.

[Brief description of drawings]

FIG. 1 is a block diagram illustrating the basic configuration of the pinch detection device of the present invention, FIG. 2 is a schematic configuration diagram of a window drive device incorporating the pinch detection device as one embodiment of the present invention, and FIG. 3 is the same. FIG. 4 is a flowchart showing a window control routine executed by the electronic control unit 4, FIG. 4 is a graph showing an example of the load reference value HY, and FIG. 5 is a graph showing an example of change of the virtual load KY with respect to the window opening. . 1 …… DC motor 2 …… Up / down switch (switch) 3 …… Battery 4 …… Electronic control device 12,13 …… Relay 16,17 …… Drive circuit 18 …… Transformer 20 …… Rotation angle detection circuit 22… … Current detection resistor 25 …… Load detection circuit

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-56-20289 (JP, A) JP-A-59-59087 (JP, A) JP-A-59-172924 (JP, A) JP-A-60- 141984 (JP, A) JP 61-30987 (JP, A) JP 61-60981 (JP, A) JP 61-64982 (JP, A) Actual development JP 62-42671 (JP, U) 62-61874 (JP, U)

Claims (1)

(57) [Claims] 1. A reference value setting means for obtaining a load reference value when a motor for driving a driven body is driven normally, and an actual load of the motor is estimated from parameters of the motor based on characteristics of the motor. In the entrapment detection device including an actual load estimation unit and an entrapment detection unit that compares the calculated load reference value with the estimated actual load to detect entrapment by the driven body, the reference value The setting means includes position detecting means for detecting an open / closed position of the driven body, virtual load estimating means for estimating a load applied to the motor according to the detected open / closed position of the driven body, and a motor being activated. An elapsed time detecting means for detecting an elapse of time from the beginning, and a calculating means for calculating the load reference value based on the detected elapsed time and the estimated virtual load. Entrapment detection apparatus characterized.