JPH05111285A - Error detector and detecting method for commutation signal of three-phase brushless motor - Google Patents

Abstract

PURPOSE:To provide an error detector for three-phase brushless motor in which an error occurring in a commutation sensor can be detected at any time. CONSTITUTION:Three-phase commutation signals having phase difference of 120 deg. are split into 60 deg. sections 1-6 having different phase states depending on the combination of high and low levels of respective phase signals. When the variation from section 1 to section 6 due to rotation of motor deviates from an order predetermined based on the information of the rotational direction of motor, a decision is made that the commutation signal is erroneous.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to abnormality detection of a three-phase brushless motor used in the field of automobile electrical equipment, and more particularly to an error detection device and error detection method for commutation signals.

[0002]

2. Description of the Related Art In recent years, the development of mechatronics technology in the automobile field has been remarkable, and various actuators have been developed. In particular, a brushless motor, which is maintenance-free and has excellent responsiveness, is attracting attention as a positioning mechanism actuator. The brushless motor detects the rotor position from the commutation sensor signal,
A motor is rotated by turning a switching element on and off according to a predetermined excitation pattern, and a hall element is often used as a commutation sensor. If an error such as noise occurs in this commutation sensor signal, it may cause malfunction or misalignment.
It can put the system in a dangerous state. The method shown in FIG. 6 is used for monitoring the commutation sensor signal in the related art. That is, in the case of a three-phase brushless motor, the commutation sensors are arranged at 120 ° intervals as shown in FIG. 6A, so that the three commutation sensors are simultaneously at a high level (hereinafter simply referred to as “high”) or at the same time. Low level (hereinafter simply called low)
Never becomes. Therefore, the circuit shown in FIG. 6 (b) determines that the time of simultaneous high or low is abnormal and sets it as a fail signal.

[0003]

However, in such a conventional method, since only the simultaneous high or the simultaneous low is detected, only the error occurring in the shaded portion of the timing chart of the commutation signal shown in FIG. 7 is detected. Could not cover the whole.

The present invention is intended to solve the above problems, and an object thereof is to provide an apparatus and method for judging an error by software based on phase information of a commutation signal when a motor rotates in a certain direction. ..

[0005]

In order to achieve the above object, an error detecting device for a commutation signal of a three-phase brushless motor according to the present invention is provided with a means for obtaining information on the rotation direction of the motor and a three-phase commutation signal. And a means for determining that there is an error in the commutation signal when the change in the phase state due to the rotation of the motor deviates from the predetermined order determined by the information on the rotation direction of the motor. ing.

[0006]

With the above construction, when the motor is rotating in a certain direction, the error can always be detected by the change in the phase state of the three-phase commutation signal.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. A timing chart of the three-phase commutation sensor is shown in FIG. However, the rotation direction is the CW direction. In the section, CSU and CSW are low and CSV is high. Similarly, in the section, CSU is low and CSV and CSW are high. This state is shown in FIG. That is, in order for the CSU signal to go from low to high, CSW must go from low to high and CSV must go from high to low. Even when CSU changes from high to low, CSW must change from high to low and CSV must change from low to high. That is, the change in the phase of the commutation signal has a predetermined order determined by the rotation direction of the motor.
This is shown in the flow chart of FIG. The phase of the commutation signal in the section of FIG. 4 is a loop of the flowchart of FIG. At the same time it is a loop in the interval,
It is a loop in the section. In this way, the phase of the commutation signal in the timing chart-section corresponds to the flow chart-loop. During CW rotation, the order of this loop change, that is, the phase state change is →
→→→→→→ …… However, the loop that starts first at the start is undefined.

By the loop for knowing such a phase state,
When an error occurs in any of the CSU, CSV, and CSW of the commutation signal, it temporarily deviates from the change order of the predetermined loop. Therefore, the error can be detected by providing a unit that determines that the loop is changed when the change order of the loop deviates from the predetermined order determined by the rotation direction information.

That is, the error detection device for the commutation signal of the three-phase brushless motor according to the present invention comprises means for obtaining information on the rotation direction of the motor, means for detecting the phase state of the three-phase commutation sensor, and rotation of the motor. And a means for determining that there is an error in the commutation signal when the change in the phase state due to the deviation from the predetermined order determined by the information on the rotation direction of the motor.

Next, the case of CCW rotation is shown in FIG. CC
The W direction may be considered in exactly the same way. But from CW to C
When the CW is switched, a delay of several msec occurs in the switching of the rotation direction due to the inertia of the motor, and a normal judgment cannot be made. Therefore, as shown in FIG. 3, the timer is set at intervals of several msec at the time of switching the direction, and the error of the commutation signal is not judged during the interval. The direction switching is in interrupt mode. As a result, the occurrence of an error in the three-phase commutation sensor can be detected at all times except for a few msec when switching the rotation direction.

[0011]

As described above, according to the present invention, noise generated in the commutation sensor can be detected at any time except at the moment when the rotation direction changes (several msec), and the malfunction of the motor due to the noise can be avoided. You can

[Brief description of drawings]

FIG. 1 is a flow chart of an error judgment at the time of CW rotation of a commutation signal error detection device of the present invention.

FIG. 2 is a flowchart of error judgment when the CCW is rotating.

FIG. 3 is an interrupt flowchart when switching between CW and CCW rotations.

FIG. 4 is a timing chart of a three-phase commutation signal.

FIG. 5 is a diagram illustrating a phase state of a commutation signal.

6A is a layout diagram of a conventional commutation sensor, and FIG. 6B is a conventional fail-safe circuit diagram.

FIG. 7 is a timing chart showing a conventional noise determination unit.

Claims (6)

[Claims] 1. A means for obtaining information on a rotation direction of a motor,
Means for detecting the phase state of the three-phase commutation signal and when the change in the phase state due to the rotation of the motor deviates from the predetermined order determined by the information of the rotation direction of the motor, it is determined that there is an error in the commutation signal. An error detection device for a commutation signal of a three-phase brushless motor, comprising: 2. The three-phase brushless according to claim 1, further comprising means for stopping the output of the means for judging that there is an error in the commutation signal for a predetermined time after the information on the rotation direction of the motor is changed. Error detection device for motor commutation signal. 3. A three-phase which determines that there is an error in the commutation signal when the change in the phase state of the three-phase commutation signal due to the rotation of the motor deviates from the predetermined order determined by the information on the rotation direction of the motor. Error detection method for commutation signal of brushless motor. 4. A predetermined change after a lapse of a predetermined time from the change of the rotation direction information of the motor, the change of the phase state of the three-phase commutation signal due to the rotation of the motor is determined by the rotation direction information of the motor. A method for detecting an error in a commutation signal of a three-phase brushless motor, which determines that there is an error in the commutation signal when out of order. 5. A three-phase commutation signal having a phase difference of 120 degrees is divided into sections of 60 degrees each having a different phase state depending on a combination of high and low signals of respective phases, and a change in the section due to rotation of a motor. A method of detecting an error in a commutation signal of a three-phase brushless motor, which determines that there is an error in the commutation signal when is out of a predetermined order determined by the information on the rotation direction of the motor. 6. A three-phase commutation signal having a phase difference of 120 degrees is divided into sections of 60 degrees each having a different phase state due to a combination of high and low signals of the respective phases, so that information on a rotation direction of a motor changes. After the lapse of a predetermined time, it is judged that there was an error in the commutation signal when the change in the above section due to the rotation of the motor deviates from the predetermined order determined by the information of the rotation direction of the motor. Motor commutation signal error detection method.