Multi-motor synchronous control method and control system for hanging system

Abstract

The invention provides a multi-motor synchronous control method and a multi-motor synchronous control system for a hanging system, and belongs to the technical field of multi-motor synchronous control. The problem that in an existing multi-motor synchronous control method, due to the fact that synchronous signals are lost, an alarm is given due to too large stress or a rack line is snapped is solved. The control method comprises the following steps: S1, collecting actual operation current values I of all motors on the suspension system; s2, the actual operation current value I is judged, if I is larger than or equal to Imin and smaller than or equal to Imax, the corresponding motor is in a dynamic synchronous operation state, and adjustment is not conducted; if Igt; if yes, the input current of the corresponding motor is controlled to be continuously reduced until the actual working current I of the corresponding motor is reduced to be within the range of Imin < = I < = Imax, and then reduction of the input current of the corresponding motor is stopped. The method has the advantage of dynamically adjusting balance so as to avoid alarm or breakage of the rack line due to overlarge stress.

Description

Technical Field

[0001] The invention belongs to the technical field of multi-motor synchronous control, and relates to a multi-motor synchronous control method and a control system for a hanging system. Background Art

[0002] In the field of hanging control systems, when hanging flexible rack lines for long-distance transportation, it is necessary to add multiple motors (hereinafter referred to as: stations) in series on a rack line to drive the rack line to run synchronously, such as the Chinese patent application publication number CN106787975A, entitled A three-motor synchronous control system and control method for hanging conveyor chains. In order to ensure the smooth operation of the rack line and prevent it from being pulled excessively, causing an alarm due to excessive force or the rack line being broken (the motor alarm threshold is set too high and is greater than the force that the rack line can withstand, then it is broken) and unable to work normally, the system needs to add a synchronous control signal to synchronously control each motor (the one that sends the synchronous control signal is hereinafter referred to as: synchronous controller). The specific control method is as follows: 1 synchronous controller, which sends out a synchronous pulse signal at a fixed time, each station receives the pulse signal for synchronization, and each station clears the error before this synchronization.

[0003] However, this control method still has the following problems: in actual operation, one or more stations may lose one or more synchronization signals due to interference from other signals or poor wiring of the synchronization signal line. After a long time, multiple stations will become asynchronous, and eventually the station that lost the synchronization signal will pull the station in front of it, causing the station that lost the signal and the station in front of it in the direction of operation to be extremely pulled, and finally the motors of the two stations will be subjected to very large forces, and eventually cause an alarm of excessive force or the rack line to be broken. Therefore, this synchronization method has very high requirements for signal lines, wiring, environment, etc., and is very prone to abnormalities. Summary of the invention

[0004] The purpose of the present invention is to solve the above technical problems and propose a multi-motor synchronous control method and control system for a suspension system that realizes dynamic synchronous operation of each motor by dynamically adjusting the actual working current of each motor.

[0005] The object of the present invention can be achieved by the following technical solutions: A multi-motor synchronous control method for a suspension system, characterized in that it comprises the following steps:

[0006] S1. Collect the actual operating current value I of each motor on the hanging system;

[0007] S2. Determine the actual operating current value I. If Imin ≤ I ≤ Imax, the corresponding motor is in the dynamic synchronous operation state and no adjustment is made. If I > Imax, control the input current of the corresponding motor to continuously decrease until the actual operating current I of the corresponding motor is reduced to within the range of Imin ≤ I ≤ Imax, and then stop reducing the input current of the corresponding motor.

[0008] Wherein, Imax and Imin are respectively the upper threshold and the lower threshold of the actual operating current when the motor is in the dynamic synchronous operation state.

[0009] In the above multi-motor synchronous control method for a hanging system, before the step S1, there is also a step:

[0010] S0. Preset the values of Imax and Imin in advance.

[0011] In the above multi-motor synchronous control method for a hanging system, in the step S0, there are also preset values of I1 and I2. I1 < Imin and I2 > Imax. When the current value I < I1 or I > I2, the entire system reports an error and stops working. Wherein, the values of I1 and I2 are respectively the lower threshold and the upper threshold of the actual operating current of the motor for the system's self-power-off protection. When the collected actual operating current value I is in the range of I1 ≤ I < Imin, control the input current of the corresponding motor to continuously increase until the actual operating current I of the corresponding motor increases to within the range of Imin ≤ I ≤ Imax, and then stop increasing the input current of the corresponding motor. When the collected actual operating current value I is in the range of Imax < I ≤ I2, control the input current of the corresponding motor to continuously decrease until the actual operating current I of the corresponding motor is reduced to within the range of Imin ≤ I ≤ Imax, and then stop reducing the input current of the corresponding motor.

[0012] In the above multi-motor synchronous control method for a hanging system, Imin is 0.1A, Imax is 0.5A, I1 is 0A, and I2 is 0.9A.

[0013] In the above multi-motor synchronous control method for a hanging system, in the step S0, there is also a preset value of I2. I2 > Imax, and the above Imin = 0. When the current value I < Imin or I > I2, the entire system reports an error and stops working. The value of I2 is the upper threshold of the actual operating current of the motor for the system's self-power-off protection. When the collected actual operating current value I is in the range of Imax < I ≤ I2, control the input current of the corresponding motor to continuously decrease until the actual operating current I of the corresponding motor is reduced to within the range of Imin ≤ I ≤ Imax, and then stop reducing the input current of the corresponding motor.

[0014] In the above-mentioned multi-motor synchronous control method for a suspension system, the Imax is 0.5A and the I2 is 0.9A.

[0015] In the above-mentioned multi-motor synchronous control method for a suspension system, the Imax corresponds to the output power of the motor being greater than or equal to the resistance value to the system generated after the balance of the system is destroyed.

[0016] In the above-mentioned multi-motor synchronous control method for a suspension system, the output power of the motors corresponding to the Imax and Imin are both much smaller than the force causing the rack line to be broken.

[0017] A multi-motor synchronous control system for a suspension system, comprising a transmission belt, a controller and at least two motors arranged on the transmission belt, all the motors are electrically connected to the controller, and is characterized in that: the controller comprises a collection unit and a judgment processing unit, the collection unit is used to collect the actual operating current value I of each motor; the judgment processing unit is used to judge the above-mentioned actual operating current value I, if Imin≤I≤Imax, the corresponding motor is in a dynamic synchronous operation state and no adjustment is made; if I>Imax, the input current of the corresponding motor is controlled to be continuously reduced until the actual working current I of the corresponding motor is reduced to within the range of Imin≤I≤Imax, and then the reduction of the input current of the corresponding motor is stopped.

[0018] In the above-mentioned multi-motor synchronous control system for a suspension system, the transmission belt is a rack line or a chain.

[0019] In the above-mentioned multi-motor synchronous control system for a suspension system, the controller further comprises a storage unit, and the storage unit is used to pre-set the Imax value, Imin value, I1 value and I2 value.

[0020] Compared with the prior art, the control method and control system have the following beneficial effects:

[0021] 1. Dynamically and independently adjust the operating current of each motor to achieve dynamic synchronous operation of each motor, so as to overcome the situation where the transmission belt is over-stressed or even broken during operation, thereby achieving dynamic balanced operation of the entire system;

[0022] 2. No synchronization signal and synchronization controller are required, which reduces wiring and system costs, reduces system complexity, and improves system operation stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a flow chart of the multi-motor synchronous control method. DETAILED DESCRIPTION

[0024] The following are specific embodiments of the present invention and the accompanying drawings to further describe the technical solution of the present invention, but the present invention is not limited to these embodiments.

[0025] Embodiment 1

[0026] like Figure 1 As shown, the multi-motor synchronous control method for the suspension system includes the following steps:

[0027] S0. Preset Imax value and Imin value.

[0028] Imax and Imin are the upper and lower thresholds of the actual working current of the motor when it is in the dynamic synchronous operation state.

[0029] S1. Collect the actual operating current value I of each motor on the hanging system;

[0030] The balanced working state means that the system is not damaged by external forces and the balance is broken. The actual working current I of each motor works within the range of Imin≤I≤Imax. In the system, a relatively small Imax value and a relatively large Imin value are set. When the system is in a balanced state, the actual working current of each motor will continuously and dynamically adjust itself within the range of Imin≤I≤Imax. Specifically, it will decrease when I reaches Imax, and then gradually increase when it decreases to Imin. According to the above logic, it will quickly and dynamically adjust within the range of Imin≤I≤Imax to ensure that the motor is always in a dynamic synchronous operation state.

[0031] S2. Determine the actual operating current value I. If Imin≤I≤Imax, the corresponding motor is in a dynamic synchronous operation state and no adjustment is made. If I>Imax, the input current of the corresponding motor is controlled to be continuously reduced until the actual working current I of the corresponding motor is reduced to within the range of Imin≤I≤Imax, and then the input current of the corresponding motor is stopped from being reduced.

[0032] Among them, Imax and Imin are respectively the upper threshold and lower threshold of the actual working current when the motor is in the dynamic synchronous operation state.

[0033] When the conveyor belt is set to work in full balance, each motor operates normally with the current value Ia, and Ia is within the range of Imin and Imax. However, full balance is theoretical. In actual work, it is difficult to achieve full balance. It is basically a dynamic balance state that is constantly approaching the full balance state. The actual working current I on each motor will change around the current value Ia. When the conveyor belt is disturbed by external force and breaks the balance, a certain point on the conveyor belt will generate resistance due to the influence of the external force, causing the transmission speed at this point to slow down. Then the motor at the rear end of the point affected by the external force will be pulled by the conveyor belt and the speed will be reduced. In order to approach a completely balanced state, the actual working current I of the motor will increase to a value greater than Ia (when the actual working current I continues to increase and reaches Imax, it will no longer increase but decrease to always maintain it within the range of Imin and Imax), so as to increase the power output by the motor to gradually overcome the resistance caused by external force interference, until the resistance is completely overcome and eliminated to restore to a new balance; at the same time, the load on the motor at the front end of the point affected by the external force becomes lighter, and the power that the motor needs to output does not need to be so large at this time, so its actual working current I will decrease to a value less than Ia (when the actual working current I continues to decrease and reaches Imin, it will no longer decrease but increase to always maintain it within the range of Imin and Imax), and cooperate with the motor at the rear end of the point affected by the external force to restore to a new balance.

[0034] In order to ensure that the system can run stably and the conveyor belt is not broken, we can set a relatively small Imax and a relatively large Imin in the system, so that I can be quickly adjusted dynamically between Imax and Imin according to the above logic to achieve synchronous dynamic balance operation. This is the dynamic adjustment and balancing ability of the motor itself. Moreover, the output power of the motor corresponding to Imax and Imin is much smaller than the force of the rack line (the conveyor belt in this embodiment is the rack line) being broken, so that no matter how the current values ​​Ia and Ib change, the power output by the motor will not break the rack line.

[0035] The actual working current I can increase or decrease smoothly and gradually, or it can increase or decrease in a step-by-step manner. The output power of the motor corresponding to Imax is greater than or equal to the resistance value to the system generated after the system balance is destroyed, so as to ensure that the current value I can overcome the resistance generated by the external force after continuously increasing within the range of Imin and Imax, thereby reaching a new dynamic balance working state.

[0036] Specifically, when the balance is broken by external force and exceeds the dynamic adjustment capability of the motor itself, that is, when the actual working current exceeds the range of Imin and Imax, the system startup control method intervenes, specifically in the following two ways:

[0037] First, in step S0, there are also preset values of I1 and I2, where I1 < Imin and I2 > Imax. During the actual operation of the motor, due to the combined influence of many factors such as external force interference, its current value I may exceed the range of Imin and Imax. In this case, a control method is required to output for adjustment to make each motor return to its own dynamic balance adjustment system. When the current value I < I1 or I > I2, the entire system reports an error and stops working. The values of I1 and I2 are respectively the lower threshold and the upper threshold of the actual working current of the motor for the system's self-power-off protection. That is to say, the actual working current of the motor cannot be too large or too small. If it is too small and lower than I1, it cannot work properly. If it is too large and higher than I2, the conveyor belt will be broken. Therefore, when the current value I < I1 or I > I2, the system cuts off the power and stops to protect, and then manual intervention is required for maintenance. When the actually measured operating current value I is in the range of I1 ≤ I < Imin, the input current of the corresponding motor is continuously increased until the actual working current I of the corresponding motor increases to the range of Imin ≤ I ≤ Imax, and then the increase of the input current of the corresponding motor is stopped, so that the corresponding motor enters its own dynamic adjustment balance; when the actually measured operating current value I is in the range of Imax < I ≤ I2, the input current of the corresponding motor is continuously decreased until the actual working current I of the corresponding motor decreases to the range of Imin ≤ I ≤ Imax, and then the decrease of the input current of the corresponding motor is stopped, so that the corresponding motor enters its own dynamic adjustment balance. By adjusting with this control method, it can not only ensure that each motor and the system can always maintain a dynamically synchronous balance operation state, but also ensure that the conveyor belt will not be pulled and broken. Specifically, Imin is 0.1A, Imax is 0.5A, I1 is 0A, and I2 is 0.9A. Of course, in addition to the above values, other values can also be used. For example, Imin is 0.05A, Imax is 0.4A, I1 is 0A, and I2 is 0.8A. The relevant parameter values can be set accordingly according to the actual situation.

[0038] Second, in step S0, there is also a preset value of I2, where I2 > Imax. In this solution, Imin = 0. Similarly, when the current value I < Imin or I > I2, the entire system reports an error and stops working; the value of I2 is the upper threshold of the actual working current of the motor for the system's self-power-off protection to ensure that the conveyor belt will not be pulled and broken; when the actually measured operating current value I is in the range of Imax < I ≤ I2, the input current of the corresponding motor is continuously decreased until the actual working current I of the corresponding motor decreases to the range of Imin ≤ I ≤ Imax, and then the decrease of the input current of the corresponding motor is stopped. Specifically, Imax is 0.5A and I2 is 0.9A; of course, in addition to the above values, Imax can also be 0.4A and I2 can be 0.8A. The relevant parameter values can also be set accordingly according to the actual situation.

[0039] Embodiment 2

[0040] The present embodiment provides a multi-motor synchronous control system for a suspension system, comprising a transmission belt, a controller and at least two motors arranged on the transmission belt, all motors are electrically connected to the controller, and the controller comprises a collection unit, a judgment processing unit and a storage unit. The collection unit is used to collect the actual operating current value I of each motor; the judgment processing unit is used to judge the actual operating current value I, if Imin≤I≤Imax, the corresponding motor is in a dynamic synchronous operation state and no adjustment is made; if I>Imax, the input current of the corresponding motor is controlled to be continuously reduced until the actual working current I of the corresponding motor is reduced to within the range of Imin≤I≤Imax, and then the input current reduction of the corresponding motor is stopped.

[0041] The storage unit is used to store the preset Imin value, Imax value, I1 and I2 parameter values, etc. The transmission belt is a rack line or a chain.

[0042] Other control principles and methods are the same as those in the first embodiment and will not be described in detail here.

[0043] The specific embodiments described herein are merely examples of the spirit of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in similar ways, but they will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.

Claims

1. A multi-motor synchronous control method for a suspension system, characterized in that: It includes the following steps: S1. Collect the actual operating current value I of each motor on the hanging system; S2. Judge the actual operating current value I. If Imin ≤ I ≤ Imax, the corresponding motor is in the dynamic synchronous operation state and no adjustment is made; if I > Imax, control the input current of the corresponding motor to continuously decrease until the actual working current I of the corresponding motor is reduced to the range of Imin ≤ I ≤ Imax, and then stop decreasing the input current of the corresponding motor; Wherein, Imax and Imin are respectively the upper threshold and the lower threshold of the actual working current when the motor is in the dynamic synchronous operation state.

2. A multi-motor synchronous control method for a suspension system according to claim 1, characterized in that: Before the step S1, there is also a step: S0. Preset the values of Imax and Imin in advance.

3. A multi-motor synchronous control method for a suspension system according to claim 2, characterized in that: In the step S0, the values of I1 and I2 are also preset. I1 < Imin, I2 > Imax. When the current value I < I1 or I > I2, the whole system reports an error and stops working; the values of I1 and I2 are respectively the lower threshold and the upper threshold of the actual working current of the motor for the system's self-power-off protection. When the collected actual operating current value I is in the range of I1 ≤ I < Imin, control the input current of the corresponding motor to continuously increase until the actual working current I of the corresponding motor increases to the range of Imin ≤ I ≤ Imax, and then stop increasing the input current of the corresponding motor. When the collected actual operating current value I is in the range of Imax < I ≤ I2, control the input current of the corresponding motor to continuously decrease until the actual working current I of the corresponding motor is reduced to the range of Imin ≤ I ≤ Imax, and then stop decreasing the input current of the corresponding motor.

4. A multi-motor synchronous control method for a suspension system according to claim 3, characterized in that: The Imin is 0.1A, Imax is 0.5A, I1 is 0A, and I2 is 0.9A.

5. The multi-motor synchronous control method for a suspension system according to claim 2, characterized in that: In the step S0, the value of I2 is also preset. I2 > Imax, and the above Imin = 0. When the current value I < Imin or I > I2, the whole system reports an error and stops working; the value of I2 is the upper threshold of the actual working current of the motor for the system's self-power-off protection; when the collected actual operating current value I is in the range of Imax < I ≤ I2, control the input current of the corresponding motor to continuously decrease until the actual working current I of the corresponding motor is reduced to the range of Imin ≤ I ≤ Imax, and then stop decreasing the input current of the corresponding motor.

6. A multi-motor synchronous control method for a suspension system according to claim 5, characterized in that: The Imax is 0.5A and I2 is 0.9A.

7. A multi-motor synchronous control method for a suspension system according to claim 3 or 5, characterized in that: The output power of the motor corresponding to Imax is greater than or equal to the resistance value to the system generated after the system balance is damaged.

8. A multi-motor synchronous control method for a suspension system according to claim 3 or 5, characterized in that: The output powers of the motors corresponding to Imax and Imin are both much smaller than the force for breaking the rack line.

9. A multi-motor synchronous control system for a suspension system, comprising a transmission belt, a controller and at least two motors arranged on the transmission belt, all the motors are electrically connected to the controller, characterized in that: The controller includes a collection unit and a judgment and processing unit. The collection unit is used to collect the actual operating current value I of each motor; the judgment and processing unit is used to judge the actual operating current value I. If Imin ≤ I ≤ Imax, the corresponding motor is in the dynamic synchronous operation state and no adjustment is made; if I > Imax, control the input current of the corresponding motor to continuously decrease until the actual working current I of the corresponding motor is reduced to the range of Imin ≤ I ≤ Imax, and then stop decreasing the input current of the corresponding motor.

10. A multi-motor synchronous control system for a hanging system according to claim 9, characterized in that: The transmission belt is a rack line or a chain.

Images