TWI843253B - Method of determining obstacles by sensing load reduction through a motor - Google Patents

Abstract

A method of determining obstacles by sensing load reduction through a motor, which includes the following steps: driving a rolling curtain to release down by the motor, monitoring the motor current and operation time point and the corresponding relationship between the motor current and the operation time point, comparing the motor current and the current threshold, when the motor current is greater than or equal to the current threshold, a timing step is performed, and a continuous drive step is performed when the motor current is less than the current threshold, timing, the operation time point where the motor current is greater than or equal to the current threshold is the starting time point, and continuously comparing the motor current and the current threshold from the starting time point, when a predetermined time length is maintained from the starting time point, the stop step is performed, when the predetermined time length is not reached, the continuous drive step is performed.

Description

Load reduction judgment obstacle sensing motor control method

The present invention relates to a motor control method, and more particularly to a load reduction determination obstacle sensing motor control method.

Generally, a large-area curtain or soft rolling curtain is released from the top to the bottom when in use, and is rolled up from the bottom to the top when the user wants to retract the curtain. Since large-area curtains or soft rolling curtains are heavy, a brushed DC motor must be used to drive the curtain or soft rolling curtain to move at a uniform speed. However, the existing curtain or soft rolling curtain cannot detect obstacles below when it is lowered, so that the motor can only continue to drive the curtain or soft rolling curtain to lower, which leads to damage to the curtain or soft rolling curtain. Therefore, a method for sensing obstacles is needed.

The present invention provides a load reduction obstacle sensing motor control method, the main purpose of which is to effectively stop the driving motor after detecting an obstacle.

To achieve the above-mentioned purpose, the load reduction determination obstacle sensing motor control method of the present invention includes: a driving step, in which a motor drives a roller blind to release downward; a monitoring step, monitoring a motor current, an operation time point and the corresponding relationship between the motor current and the operation time point; a comparison step, comparing the motor current and a current threshold, when the motor current is greater than or equal to the current threshold, a timing step is executed, and when the motor current is less than the current threshold, a continuous driving step is executed; the timing step defines the operation time when the motor current is greater than or equal to the current threshold. The time point is a starting time point, and the motor current and the current threshold are continuously compared from the starting time point. When the state of the motor current being greater than or equal to the current threshold is maintained for a predetermined time length from the starting time point, a stop step is executed. When the state of the motor current being greater than or equal to the current threshold does not reach the predetermined time length from the starting time point, the continuous driving step is executed; the continuous driving step continuously drives the roller blind downward to release, and repeatedly executes the monitoring step and the comparison step; and the stop step stops the motor from running and stops driving the roller blind downward.

As can be seen from the above, the present invention mainly monitors the real-time motor current, the operating time point and the corresponding relationship between the motor current and the operating time point. When the motor current is greater than or equal to the current threshold and maintains the predetermined time length, the motor operation is stopped, thereby preventing the roller shutter from continuing to move downward, so as to achieve the purpose of effectively stopping the driving motor after detecting an obstacle.

S1: Driving step

S2: Monitoring step

S3: Comparison step

S4: Timing step

S5: Continuous driving step

S6: Stop step

I: Motor current

V: Current threshold

T: Operation time point

T1: Starting time point

T2: Scheduled duration

10: Motor

20: Roller blinds

Figure 1 is a flow chart of the load reduction determination obstacle sensing motor control method of this invention.

Figure 2 is a diagram showing the roller shutter touching a person when it is lowered.

Figure 3A is a diagram showing the motor current and current threshold when the roller blind does not touch an obstacle. It is worth mentioning that, since this diagram shows the time and current value of the roller blind being lowered, the current is represented by a negative value.

Figure 3B is a diagram showing the motor current and current threshold when the roller blind hits an obstacle. It is worth mentioning that since this diagram shows the time and current value of the roller blind being lowered, the current is represented by a negative value.

The present invention provides a load reduction determination fault sensing motor control method, please refer to FIG. 1-3B, including: a driving step S1, a motor 10 drives a roller curtain 20 to release downward at a uniform speed; a monitoring step S2, monitoring a real-time motor current I, an operation time point T of the motor 10 and the corresponding relationship between the motor current I and the operation time point T. To further explain, the operation time point T of the motor 10 It refers to the time when the roller blind 20 starts to be lowered from the fully rolled-up state. For example, when the roller blind 20 starts to be lowered for 5 seconds from the fully rolled-up state, it can be understood that the operation time point T of the motor 10 is 5 seconds. The corresponding relationship between the motor current I and the operation time point T refers to the motor current I at the operation time point T. When the roller blind 20 does not touch any obstacle, please refer to FIG. 3A. The value of the motor current I is a constant. The motor current I changes significantly only when the motor 10 starts and stops, so that the roller blind 20 can be released downward at a uniform speed; a comparison step S3 compares the motor current I and a current threshold V at the same operation time point T. When the motor current I is greater than or equal to the current threshold V, a timing step S4 is executed. When the motor current I is less than the current threshold V, a continuous driving step S5 is executed. In the step S3, the current threshold V is predefined by the user. For example, the motor current I at the operation time point T of the 5th second and the current threshold V at the operation time point of the 5th second are compared. If the motor current I at the operation time point of the 5th second is greater than or equal to the current threshold V, the timing step S4 is executed. When the motor current I is less than the current threshold V, the continuous driving step S5 is executed.

The timing step S4, please refer to FIG. 3B, defines the operation time point T when the motor current I is greater than or equal to the current threshold V as a starting time point T1, and continuously compares the motor current I and the current threshold V from the starting time point T1. When the state of the motor current I being greater than or equal to the current threshold V is maintained for a predetermined time from the starting time point T1, If the motor current I is greater than or equal to the current threshold V for a predetermined time length T2 from the start time point T1, the continuous driving step S5 is executed. In this embodiment, the predetermined time length T2 is predefined by the user. For example, when the motor current I is greater than or equal to the current threshold V for a predetermined time length T2 from the start time point T1, the continuous driving step S5 is executed. If the motor current I is greater than or equal to the current threshold V, the 5th second is the starting time point T1. If the predetermined time length T2 is 3 seconds, the state of the motor current I being greater than or equal to the current threshold V lasts from the 5th second to the 8th second, and the stop step S6 is executed. Otherwise, if the motor current I is greater than or equal to the current threshold V only lasts from the 5th second to the 8th second, the motor current I is greater than or equal to the current threshold V only lasts from the 5th second to the 8th second. At the 6th second, the continuous driving step S5 is executed; the continuous driving step S5 continuously drives the rolling curtain 20 to be released downward at a uniform speed, and the monitoring step S2 and the comparison step S3 are repeatedly executed until the rolling curtain 20 is released to a fixed position; the stopping step S6 stops the operation of the motor 10, and then stops driving the rolling curtain 20 to continue to move downward.

From the above, it can be known that if the curtain or flexible rolling curtain 20 touches an obstacle or a person during the lowering process, the obstacle or the person will exert a resistance force on the curtain or flexible rolling curtain 20, so that the kinetic energy that the motor 10 needs to output increases, thereby increasing the torque of the motor 10 and causing the motor current I to rise, thereby judging that the curtain or flexible rolling curtain 20 has touched an obstacle or a person.

In addition, when the curtain or flexible rolling curtain 20 touches an obstacle or a person during the lowering process, the motor current I is greater than or equal to the current threshold V. This state needs to be maintained for the predetermined time length T2 before executing the stop step S6, thereby avoiding the problem of excessive sensitivity caused by the curtain or flexible rolling curtain 20 only briefly touching an obstacle and then stopping the lowering.

The present invention mainly monitors the real-time motor current I, the operation time point T and the corresponding relationship between the motor current I and the operation time point T. When the motor current I is greater than or equal to the current threshold V and maintains the predetermined time length T2, the motor 10 is stopped, thereby preventing the roller shutter 20 from continuing to move downward, so as to achieve the purpose of effectively stopping the driving motor 10 after detecting an obstacle.

S1: Driving step

S2: Monitoring step

S3: Comparison step

S4: Timing step

S5: Continuous driving step

S6: Stop step

Claims (1)

A load reduction determination obstacle sensing motor control method includes: a driving step, in which a motor drives a roller blind to be released downward; a monitoring step, in which a motor current, an operation time point and the corresponding relationship between the motor current and the operation time point are monitored; a comparison step, in which the motor current and a current threshold are compared, and when the motor current is greater than or equal to the current threshold, a timing step is executed, and when the motor current is less than the current threshold, a continuous driving step is executed; the timing step defines the operation time point when the motor current is greater than or equal to the current threshold as a time point when the motor current is greater than or equal to the current threshold. At the start time point, the motor current and the current threshold are continuously compared from the start time point. When the state of the motor current being greater than or equal to the current threshold is maintained for a predetermined time length from the start time point, a stop step is executed. When the state of the motor current being greater than or equal to the current threshold does not reach the predetermined time length from the start time point, the continuous driving step is executed; the continuous driving step continuously drives the roller blind downward to release, and repeatedly executes the monitoring step and the comparison step; and the stop step stops the motor from running and stops driving the roller blind downward.

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