JPH04306387A - Controlling method of power window for car - Google Patents

Abstract

PURPOSE:To detect a lock always at a constant detection level irrespective of load condition by obtaining mean value of a load current at the time of normal operation for every opening and shutting operation of a window glass, making it as a reference load current in that time, and making it as reference value to make a decision of the lock. CONSTITUTION:When an electrically driven motor M starts rotating drive, a current detection circuit detects a load current I to input it to an A/D converter of a control section. After that, the control section makes sampling of the load current I after the elapse of the first set time t0 from the start of driving. Then, the control section obtains means value of the load current I making a sampling within t1 time after the elapse of the second set time t1, and it is a reference load current i1. Value i1+DELTAi1 adding set value DELTAi1 to the reference load current i1 is compared with the load current I detected by the current detection circuit, and when it reaches I>=i1+DELTAi1, it is decided as the lock to break an operation stop signal, and the electrically driven motor M is stopped.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling power windows in automobiles.

0002

[Prior Art] In a power window device that opens and closes a car window glass by forward and reverse rotation of an electric motor, conventional lock detection (locking when the window glass is fully closed or fully open, and locking due to a person being caught in the window) is not possible. This was done by detecting when the load current exceeded a set value (for example, in Japanese Patent Application Laid-open No. 6
1-64982).

0003

[Problems to be Solved by the Invention] The operating load for opening and closing automobile window glasses changes, for example, between winter and summer, and the load is particularly light in summer, even though the load current is the same for the same window glass. It is never a constant value; its value changes each time it is activated.

Therefore, in the conventional method described above, if the set value of the load current for lock detection is determined based on a heavy load condition (for example, in winter), an unnecessarily excessive overload may occur in a light load condition (for example, in summer). Not only is a current required, but the effect of pinching a human body will be greater.On the other hand, if the setting value is determined based on a light load condition, a slight load fluctuation may cause a misjudgment of locking when the load is heavy. For example, there is a problem in that the drive may stop before the window glass is sufficiently pressed against the weather strip (before it is fully closed).

The main object of the present invention is to solve the above-mentioned conventional problems.

[0006]

[Means for Solving the Problems] The present invention provides a power window device for an automobile, each time a window glass is opened/closed, after a first set time to has elapsed from the start of load drive, and within a second set time t1. Find the average value from the sampled load current I, set it as the reference load current i1, and set it as the second
The load current I sampled after the set time t1 has elapsed
The first feature is that when the load current i1 exceeds the set value △i1, the electric motor is determined to be locked and the load drive of the electric motor is stopped. Within time t1, when the sampled load current I exceeds the value obtained by adding the set value △i1 to the previous reference load current i1' obtained during the previous opening/closing operation, it is determined that the lock is established and the electric motor loads. The second feature is that it performs control to stop the.

[0007]

[Operation] Due to the first feature above, lock detection can always be performed at a constant detection level regardless of the load condition, and the second feature allows lock detection to be performed even if a human body is caught during operation. can reduce the impact on

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the present invention will be described below with reference to the drawings.

FIG. 1 shows an electric motor M used in the present invention.
FIG. 2 is a block diagram showing an example of a drive control circuit, in which the drive control circuit ECU includes a control section that has a RAM (random access memory) and an A/D converter and mainly performs calculations, and a control section that converts switch inputs into electric signals. an input interface that converts the signal into an electrical signal and inputs it to the control section; a drive circuit that drives the load based on the signal from the control section; and an A/D converter of the control section that detects the load current and converts it into an electrical signal. It is composed of an input current detection circuit and a power supply circuit that supplies power to each of them, and the control section performs the following control.

FIGS. 2A, 2B and 2C are diagrams respectively showing three patterns of load current characteristics during window glass opening/closing operations.

FIG. 2A shows the change in the load current I during normal operation, for example, from a fully open state to a window glass closing operation to a fully closed state, and the solid line indicates that when the load is small, The dotted line indicates the case where the load is large.

In the pattern shown in FIG. 2A, for example, an up signal is input to the control unit via the input interface by switch operation, and the electric motor M is driven to rotate via the drive circuit in response to the signal from the control unit. When starting, the current detection circuit detects the load current and inputs it to the A/D converter of the control section, and the control section samples the load current I after the first set time to has elapsed from the start of driving. 1st above
The set time to is a time for avoiding rush current that occurs at the start of load driving.

After the elapse of the second set time t1, the average value of the load current I sampled within the time t1 is determined, and this is set as the reference load current i1, and the value i1 + which is the sum of the reference load current i1 and the set value Δi1 is calculated. △i1 is compared with the load current I detected by the current detection circuit, and I≧i1
When +Δi1 is reached, it is determined that the lock is present, and an operation stop signal is issued to stop the drive of the electric motor M.

In the above, the reference load current i1 is stored in memory, and the stored value is used as the previous reference load current i1' when driving the load next time. That is, when driving the load next time, the load current I sampled after the elapse of time to is first compared with the previous reference load current i1', and I
If ≦i1', as in the previous case, find the average value of the load current I sampled within time t1 and use it as the reference load current i1 at that time, and from then on, when I≧i1 +△i1, the operation stop signal will be activated. emanate.

In FIG. 2(A), for example, if the load is larger this time as shown by the dotted line compared to the previous operation shown by the solid line, then the load current I sampled within time t1 this time is I>i1'. Become. In such a case, compare the sampled load current I with the value i1 ′+△i1, which is the sum of the previous reference load current i1 ′ and the set value △i1, and if I<i1 ′+△i1, Same as last time
The average value of I sampled within one hour is set as the current reference load current i1, and when I≧i1 +△i1, an operation stop signal is issued.

In this way, I is the reference load current i at that time.
By determining a lock when the value is equal to or greater than the sum of 1 and Δi1, lock detection can be performed in a constant state regardless of changes in load size.

For example, when the window glass is completely closed from a state where it is slightly open, the window glass becomes fully closed in the middle of the second set time t1, as shown in FIG. 2(B). There is. For example, when the closing operation is performed in a fully closed state or a state very close to fully closed, a pattern as shown in FIG. 2(C) will be obtained. Furthermore, if a foreign object (such as a human body) is caught during or immediately after the closing operation of the window glass, the procedure shown in Figure 2 above will also occur.
B) or (C) pattern, and in either case t1
The load current I sampled within the time is larger than the previous reference load current i1', and I≧i1'+△i1
becomes.

In this way, the load current I sampled within time t1 is set to the previous reference load current i1'.
When the value is greater than or equal to i1, it is determined to be locked,
An operation stop signal is issued to stop driving the electric motor M.

When the reference load current i1 at that time is determined from the solid line to the dotted line in FIG. 2(A), the memory is rewritten using the newly determined reference load current i1 as i1' for the next If the reference load current i1 is not determined at that time as shown in (B) and (C) in Figure 2, the memory is not rewritten and the previous i1' is stored as is. .

The control in (A), (B), and (C) of FIG. 2 above is collectively expressed in a flowchart as shown in FIG.
It becomes as shown in .

[0021]

As described above, according to the present invention, the average value of the load current during normal operation is determined every time a window glass is opened/closed, and this is used as the reference load current at that time, and this is used as the reference value for locking. By adopting the method of making a judgment, lock detection can always be performed at a constant detection level regardless of the load state.

Furthermore, the value of the reference load current determined for each switching operation is memorized, and locking is determined using the previously stored reference load current as the reference value until the reference load current is determined for the next switching operation. This method has the effect of reducing the impact on the human body even if, for example, a human body gets caught during operation, and since these controls depend on software, there is little impact on cost. Together with this, it is extremely effective in practice.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an example of an electric motor drive control circuit used in the present invention.

[Figure 2] Load current characteristics during window glass opening/closing operation (A),
It is shown in three patterns (B) and (C),

[
FIG. 3 is a flowchart showing an embodiment of the control method of the present invention.

Claims (2)

[Claims] Claim 1: In a power window device for an automobile that uses an electric motor to open and close a window glass, after a first set time to has elapsed from the start of load driving of the electric motor,
Load current I sampled within second set time t1
Find the average value from , set it as the reference load current i1, and then compare the sampled load current I with the value i1 + △i1, which is the sum of the reference load current i1 and the set value △i1, and find that I is i1 + △ A method for controlling a power window for an automobile, characterized in that when the power window exceeds i1, it is determined to be locked and the load drive of the electric motor is stopped. 2. In the control method for an automobile power window according to claim 1, the load current I sampled within the second set time t1 and the previous reference load current i1' obtained during the previous opening/closing operation are used. The set value △i1 is added to the value i1 ′+△i1, and I is i1 ′+△
A method for controlling a power window for an automobile, characterized in that when the power window exceeds i1, it is determined to be locked and the load drive of the electric motor is stopped.