A double electric roller control method and system suitable for a sorting trolley

Abstract

The present application relates to the technical field of sorting trolley, and discloses a double electric roller control method and system suitable for a sorting trolley, comprising the following steps: S1, adopting a tray gantry double-drive motion platform, installing one permanent magnet synchronous electric roller on each side of the platform, and driving the belt to run first, tension control is performed on the belt, and according to the different rotating directions of the electric roller 1 and the electric roller 2 when the upper package and the lower package, the electric roller is separately controlled, and the difference between the master motor and the slave motor is generated. The double electric roller control method and system suitable for the sorting trolley can use two small-power electric rollers to work synchronously through the control system and method, realize the consistency of the output torque, speed and position of the electric roller, and realize the stable stopping and accurate landing of the large package on the trolley tray, complete the large sorting, and has the advantages of reducing the manufacturing cost of the small-power electric roller, reducing the development cost of the large-power electric roller and reducing the mechanical cost of the trolley tray.

Description

Technical Field

[0001] This invention relates to the field of sorting cart technology, specifically to a dual electric roller control method and system applicable to sorting carts. Background Technology

[0002] Cross-belt sorting trolleys are an important component of cross-belt sorting systems. They are trolleys carrying small belt conveyors that can move in a loop along a track. Based on scanned barcode information, they unload goods destined for different locations into different slots. The advantages of cross-belt sorting trolleys are high sorting efficiency, high sorting accuracy, no damage to goods, whole-machine drive, redundant design, and extremely high reliability and scalability.

[0003] The belt conveyor on the trolley uses an active electric roller paired with a driven roller. The active electric roller is driven by a single driver to drive the belt. The belt drive principle of the current cross-belt sorting machine's large and small item sorting trolleys is the same, but the large item sorting trolley uses a larger and more powerful electric roller to drive the belt. It simply uses two servo motors to drive it. Due to the coupling effect between the two motors, the output torque, speed and position will be inconsistent, which will reduce the scale effect of the electric roller and trolley mechanical parts and increase the cost of research and development and manufacturing. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a dual electric roller control method and system suitable for sorting trolleys. It features a single driver that drives two low-power electric rollers (electric rollers for small-item sorting trolleys) to jointly drive a belt conveyor, thereby achieving sorting functionality. This method can increase the scale effect of producing electric rollers of the same model, meet the sorting needs of different sorting trolleys by standardizing the electric roller model, and save on the material usage of trolley structural components, thus solving the problems mentioned in the background technology.

[0005] This invention provides the following technical solution: a dual electric roller control method suitable for sorting carts, comprising the following steps:

[0006] S1. A tray gantry dual-drive motion platform is adopted. A permanent magnet synchronous electric roller is installed on each side of the platform to drive the belt. First, the belt tension is controlled. According to the different rotation directions of the belt during the upper and lower wrapping, the electric rollers No. 1 and No. 2 will produce a main motor and a slave motor when controlled separately. The motor in the wrapping speed direction is the main motor. Experiments show that when the two electric rollers have the same speed, the main motor outputs a larger torque.

[0007] S2. Two motors use tension observers to measure the belt tension, thereby determining the torque that the two motors should output for the current package on the pallet. Treating the tension F as a state variable, and given the very high sampling frequency of the controller, the tension can be approximated as a constant value within the same control cycle. Thus, a dynamic model of the main motor is established. , , , ;

[0008] S3. After observing the belt tension, the tension is used as feedback to correct the gantry synchronization control. Based on the observed torque and speed, the two electric drums are controlled to output the same torque, speed and position. The gantry dual drive system is based on the "three closed loop" parallel control structure. The tension difference and speed difference calculated by the two electric drums are used as current and position compensation to correct the system.

[0009] S4. The electric drum is compensated for synchronization error through this modified cross-coupling synchronization control, which corresponds to the dynamic characteristics of the following error and the synchronization error, respectively. An additional tensor observer is designed to suppress the influence of coupling, thus further improving the synchronization accuracy of the dual drive system.

[0010] S5 ;

[0011] Calculated from the above formula and These are used for speed feedback of electric drum 1 and electric drum 2 respectively, where k is the feedback balance coefficient, 0 < k < 1;

[0012] S6 ;

[0013] The current compensation value is determined by using the output torque proportionality coefficient determined by the above formula. , This is the system compensation coefficient.

[0014] Preferably, the driver of the pallet gantry dual-drive motion platform uses an STM32F103 + two pre-drives + 12 MOSFETs + dual resistors for the lower bridge arm sampling *2, and the encoder uses Hall element magnetizing steel counting.

[0015] Preferably, the For the observed state variable, For tension, This refers to the motor speed. For output quantity, The output of the observer, Here, is the coefficient of the physical quantity, where To control the output signal, For feedback gain, The torque coefficient of the electric drum. Let q be the current of the electric drum 1. Let q be the q-axis current of the electric drum 2.

[0016] A dual-electric roller control system for sorting carts includes the following steps:

[0017] Step 1: Start;

[0018] Step 2: Receive the pack loading or pack placement control signal;

[0019] Step 3: Electric rollers 1 and 2 move;

[0020] Step 4: Calculate the package weight simultaneously using a tension monitor;

[0021] Step 5: Compare the observed tension values ​​of electric roller 1 and electric roller 2 as reference values ​​for the correction of synchronous control parameters of the pallet gantry dual-drive motion platform;

[0022] Step Six: Electric Drum 1 and Electric Drum 2 output the same torque, speed, and displacement.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] This invention relates to a dual electric roller control method and system for sorting trolleys. Through this control system and method, two low-power electric rollers can work synchronously to achieve consistent output torque, speed, and position of the electric rollers. This enables large items to be stably stopped and accurately placed on the trolley pallet, thus completing the sorting of large items. Economically, it has the advantages of reducing the manufacturing cost of low-power electric rollers, reducing the R&D cost of high-power electric rollers, and reducing the mechanical cost of the trolley pallet. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the system of the present invention;

[0026] Figure 2 This is a block diagram illustrating the principle of the tension observer of the present invention;

[0027] Figure 3 This is a block diagram illustrating the synchronous control principle of the present invention;

[0028] Figure 4 This is a schematic diagram of the control method of the present invention. Detailed Implementation

[0029] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] Please see Figure 1-4 A dual-electric roller control method suitable for sorting carts includes the following steps:

[0031] S1. A tray gantry dual-drive motion platform is adopted. A permanent magnet synchronous electric roller is installed on each side of the platform to drive the belt. First, the belt tension is controlled. According to the different rotation directions of the belt during the upper and lower wrapping, the electric rollers No. 1 and No. 2 will produce a main motor and a slave motor when controlled separately. The motor in the wrapping speed direction is the main motor. Experiments show that when the two electric rollers have the same speed, the main motor outputs a larger torque.

[0032] S2. Two motors use tension observers to measure the belt tension, thereby determining the torque that the two motors should output for the current package on the pallet. Treating the tension F as a state variable, and given the very high sampling frequency of the controller, the tension can be approximated as a constant value within the same control cycle. Thus, a dynamic model of the main motor is established. , , , ;

[0033] S3. After observing the belt tension, the tension is used as feedback to correct the gantry synchronization control. Based on the observed torque and speed, the two electric drums are controlled to output the same torque, speed and position. The gantry dual drive system is based on the "three closed loop" parallel control structure. The tension difference and speed difference calculated by the two electric drums are used as current and position compensation to correct the system.

[0034] S4. The electric drum is compensated for synchronization error through this modified cross-coupling synchronization control, which corresponds to the dynamic characteristics of the following error and the synchronization error, respectively. An additional tensor observer is designed to suppress the influence of coupling, thus further improving the synchronization accuracy of the dual drive system.

[0035] S5 ;

[0036] Calculated from the above formula and These are used for speed feedback of electric drum 1 and electric drum 2 respectively, where k is the feedback balance coefficient, 0 < k < 1;

[0037] S6 ;

[0038] The current compensation value is determined by using the output torque proportionality coefficient determined by the above formula. , As the system compensation coefficient, this control system and method can use two low-power electric rollers to work synchronously, so as to achieve consistent output torque, speed and position of the electric rollers, thereby enabling large items to be stably stopped and accurately placed on the trolley pallet, completing the sorting of large items. It has the advantages of reducing the manufacturing cost of low-power electric rollers, reducing the R&D cost of high-power electric rollers and reducing the mechanical cost of trolley pallets.

[0039] Among them, the driver of the pallet gantry dual-drive motion platform uses STM32F103 + two pre-drive + 12 MOSFETs + dual resistors for lower bridge arm sampling *2, and the encoder uses Hall element magnetic steel counting.

[0040] in; For the observed state variable, For tension, This refers to the motor speed. For output quantity, The output of the observer, Here, is the coefficient of the physical quantity, where To control the output signal, For feedback gain, The torque coefficient of the electric drum. Let q be the current of the electric drum 1. Let q be the q-axis current of the electric drum 2.

[0041] A dual-electric roller control system for sorting carts includes the following steps:

[0042] Step 1: Start;

[0043] Step 2: Receive the pack loading or pack placement control signal;

[0044] Step 3: Electric rollers 1 and 2 move;

[0045] Step 4: Calculate the package weight simultaneously using a tension monitor;

[0046] Step 5: Compare the observed tension values ​​of electric roller 1 and electric roller 2 as reference values ​​for the correction of synchronous control parameters of the pallet gantry dual-drive motion platform;

[0047] Step Six: Electric rollers No. 1 and No. 2 output the same torque, speed, and displacement. A single drive unit drives two low-power electric rollers (electric rollers for small sorting carts) to jointly drive the belt conveyor, thereby achieving the sorting function. This can increase the scale effect of producing electric rollers of the same model. By standardizing the electric roller model, the sorting needs of different sorting carts can be met, saving material usage for cart structural components. The two electric rollers and the belt are considered as a whole system for control, achieving synchronization of the two motors in output torque, speed, and position.

[0048] like Figure 1 As shown, two low-power electric rollers are installed on a special large-item tray, and a self-driving two-motor driver is used for control. The controller communicates with the host computer via a 485 bus for parameter debugging, curve acquisition and motion control.

[0049] like Figure 2 and Figure 3 As shown, the two electric rollers operate in torque control mode. At the beginning of operation, a tension observer is used to calculate the tension on the two electric rollers. The STM32 receives the speed and current signals from electric rollers 1 and 2 used to drive the belt, and controls the synchronous operation of the electric rollers on both sides of the tray. The driver internally transmits parameters through shared memory, and the driver is connected to the outside via a 485 bus.

[0050] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0051] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A dual-electric roller control method suitable for sorting carts, characterized in that, Includes the following steps: S1. A tray gantry dual-drive motion platform is adopted, with a permanent magnet synchronous electric roller installed on each side of the platform to jointly drive the belt. First, the belt tension is controlled. According to the different rotation directions of the belt during the upper and lower wrapping, the electric rollers No. 1 and No. 2 will produce a main motor and a slave motor when controlled separately. The motor in the wrapping speed direction is the main motor. Experiments show that when the speeds of the two electric rollers are the same, the main motor outputs a larger torque. S2. Two motors use tension observers to measure the belt tension, thereby determining the torque that the two motors should output for the current package on the pallet. Treating the tension F as a state variable, and given the very high sampling frequency of the controller, the tension can be approximated as a constant value within the same control cycle. Thus, a dynamic model of the main motor is established. , , , ; S3. After observing the belt tension, the tension is used as feedback to correct the gantry synchronization control. Based on the observed torque and speed, the two electric drums are controlled to output the same torque, speed and position. The gantry dual drive system is based on the "three closed loop" parallel control structure. The tension difference and speed difference calculated by the two electric drums are used as current and position compensation to correct the system. S4. The electric drum is compensated for synchronization error through this modified cross-coupling synchronization control, which corresponds to the dynamic characteristics of the following error and the synchronization error, respectively. An additional tensor observer is designed to suppress the influence of coupling, thus further improving the synchronization accuracy of the dual drive system. S5、 ； Calculated from the above formula and These are used for speed feedback of electric drum 1 and electric drum 2 respectively, where k is the feedback balance coefficient, 0 < k < 1; S6、 ； The current compensation value is determined by using the output torque proportionality coefficient determined by the above formula. ; The For the observed state variable, For tension, This refers to the motor speed. For output quantity, Let A, B, and C be the output of the observer, and let A, B, and C be the physical quantity coefficients. To control the output signal, For feedback gain, Let q be the current of the electric drum 1. Let q be the q-axis current of the electric drum 2.

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