Commercial vehicle battery swap station-based frequency converter positioning method and system

Abstract

The invention discloses a frequency converter positioning method and system based on a commercial vehicle battery swap station, and relates to the technical field of battery swap stations. The system comprises a PLC, a frequency converter, an encoder and a motor, the PLC is responsible for acquiring position parameters of the encoder and receiving state data of the frequency converter, and the PLC sends control parameters to the frequency converter, so that the frequency converter controls the motor to execute corresponding operation, and the frequency converter positioning method based on the commercial vehicle battery swap station is achieved. According to the system, a logic control program is written by the system, so that combined control of common components such as an encoder, a frequency converter and a motor is realized, and absolute positioning control is realized. The frequency converter improves the universality of products, reduces the material cost and the management cost of product manufacturing, and improves the positioning precision and the positioning speed compared with a traditional frequency converter.

Description

Technical Field

[0001] The present invention relates to the technical field of battery swap stations, and in particular to a method and system for positioning a frequency converter in a commercial vehicle battery swap station. Background Art

[0002] In the new energy vehicle industry, commercial vehicle battery swap stations are key infrastructure to support the endurance of electric vehicles, and their safety and efficiency are of vital importance. Given the heavy weight of the battery packs equipped in commercial vehicles, battery swap stations generally use an automated battery swap system that combines battery swap robots with roller tracks, which optimizes the battery swap process to a certain extent.

[0003] Although the rolling friction between the roller and the track reduces mechanical wear, there is a lack of a stable hard connection between the two. During long-term and intensive use, sliding displacement is inevitable. This displacement will not only affect the operating stability of the battery swap robot, but may also cause positioning deviation during the battery swap process, thereby affecting the efficiency and safety of the battery swap.

[0004] To solve this problem, existing technologies usually use external encoders to monitor and determine the actual position of the battery swap robot in real time. However, although this method is effective, it places extremely high demands on hardware equipment. Not only does it require the motor to be able to perform precise positioning movements according to the position of the encoder, but it also requires the hardware equipment to have high reliability and stability. However, the hardware equipment currently on the market often cannot meet these requirements at the same time, resulting in the inability to achieve precise positioning or high costs, making it difficult to achieve large-scale promotion and application.

[0005] In order to overcome the above technical difficulties, the present invention proposes a positioning method and system to solve this problem. The method and system not only reduce the equipment cost, but also improve the stability and accuracy of positioning. Summary of the invention

[0006] The main technical problem solved by the present invention is to provide a method and system for positioning a frequency converter of a commercial vehicle battery swap station, which not only reduces the equipment cost but also improves the stability and accuracy of positioning.

[0007] In order to solve the above technical problems, a technical solution adopted by the present invention is:

[0008] A method for locating a frequency converter in a commercial vehicle battery swap station comprises the following steps:

[0009] Step 1: trigger positioning, set target parameters, including target position P0, target speed V0, acceleration Acc0, deceleration Dec0 and positioning accuracy OffSet, and obtain the actual position Pe_Act of the encoder;

[0010] Step 2: Calculate the distance S0 between the actual position Pe_Act and the target position P0, S0 = P0 - Pe_Act;

[0011] Step 3: Calculate the maximum speed V_Max of the motor based on the triangle positioning theory;

[0012] Step 4: By comparing the target speed V0 and the maximum speed V_Max, the minimum speed is obtained as the positioning speed V1;

[0013] Step 5: According to the parameters of positioning speed V1, acceleration Acc0 and deceleration Dec0, control the inverter to make the motor perform JOG motion;

[0014] Step 6: Calculate the distance S1 required to reduce the current running speed V_Act to 0 according to the deceleration Dec0. The calculation formula is S1 = V_Act 2 / (2*Dec0);

[0015] Step 7: Compare S1 and S0, and determine whether to execute deceleration control or continue acceleration and constant speed control;

[0016] If S1 ≥ S0, jump to step 8 to execute deceleration process control;

[0017] If S1<S0, return to the third step to continue to execute the acceleration uniform speed process control;

[0018] Step 8: Calculate the distance S2 between the current actual position Pe_Act and the target position P0, S2 = P0 - Pe_Act;

[0019] Step 9: Calculate the deceleration Dec1 required to reduce the current running speed V_Act to 0 and the running distance to S2, Dec1 = V_Act 2 / (2*S2);

[0020] Step 10: According to the deceleration Dec1, control the inverter to decelerate the motor in JOG motion until the speed is reduced to 0;

[0021] Step 11: Compare whether the distance S2 from the target position P0 is less than the positioning accuracy OffSet;

[0022] If S2≤OffSet, jump to step 12;

[0023] If S2>OffSet, jump to step 8 to continue the deceleration process control;

[0024] Step 12: After completing positioning, stop moving.

[0025] Furthermore, the maximum speed V_Max in step 3 is calculated as follows: V_Max=2*S0*Acc0*Dec0 / (Acc0+Dec0);

[0026] Furthermore, in step 4, the basis for obtaining the positioning speed V1 is:

[0027] If the maximum speed V_Max> target speed V0, then the positioning speed V1=target speed V0;

[0028] If the maximum speed V_Max≤target speed V0, the positioning speed V1=maximum speed V_Max.

[0029] A frequency converter positioning system based on a commercial vehicle battery swap station includes a PLC, a frequency converter, an encoder and a motor. The PLC is responsible for obtaining the position parameters of the encoder and receiving the status data of the frequency converter. The PLC sends control parameters to the frequency converter, so that the frequency converter controls the motor to perform corresponding operations, thereby realizing a frequency converter positioning method based on a commercial vehicle battery swap station.

[0030] Furthermore, the PLC is a Siemens 1511 controller, the frequency converter is a Siemens G120C frequency converter, the encoder is a multi-turn absolute encoder, and the motor is a three-phase asynchronous reduction motor.

[0031] Furthermore, the PCL uses Profinet communication to communicate with the frequency converter and the frequency converter respectively.

[0032] The beneficial technical effects of the present invention are:

[0033] This system realizes the combined control of common encoders, inverters, motors and other components by writing its own logic control program, and realizes absolute positioning control. It improves the versatility of the product, reduces the material cost and management cost of product manufacturing, and improves the positioning accuracy and positioning speed compared to traditional inverters. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a schematic diagram of the flow of the positioning method of the present invention;

[0035] Figure 2 It is a structural schematic diagram of the positioning system of the present invention. DETAILED DESCRIPTION

[0036] In order to more clearly understand the technical means of the present invention and implement it according to the contents of the specification, the specific implementation methods of the present invention are further described in detail below in conjunction with the drawings and examples. The following examples are used to illustrate the present invention but are not used to limit the scope of the present invention.

[0037] This specific embodiment discloses in detail a method for locating a frequency converter based on a commercial vehicle battery swap station. Figure 1 As shown, the following steps are included:

[0038] Step 1: trigger positioning, set target parameters, including target position P0, target speed V0, acceleration Acc0, deceleration Dec0 and positioning accuracy OffSet, and obtain the actual position Pe_Act of the encoder;

[0039] Step 2: Calculate the distance S0 between the actual position Pe_Act and the target position P0, S0 = P0 - Pe_Act;

[0040] Step 3: Calculate the maximum speed V_Max of the motor based on the triangle positioning theory;

[0041] Step 4: By comparing the target speed V0 and the maximum speed V_Max, the minimum speed is obtained as the positioning speed V1;

[0042] Step 5: According to the parameters of positioning speed V1, acceleration Acc0 and deceleration Dec0, control the inverter to make the motor perform JOG motion;

[0043] Step 6: Calculate the distance S1 required to reduce the current running speed V_Act to 0 according to the deceleration Dec0. The calculation formula is S1 = V_Act 2 / (2*Dec0);

[0044] Step 7: Compare S1 and S0, and determine whether to execute deceleration control or continue acceleration and constant speed control;

[0045] If S1 ≥ S0, jump to step 8 to execute deceleration process control;

[0046] If S1<S0, return to the third step to continue to execute the acceleration uniform speed process control;

[0047] Step 8: Calculate the distance S2 between the current actual position Pe_Act and the target position P0, S2 = P0 - Pe_Act;

[0048] Step 9: Calculate the deceleration Dec1 required to reduce the current running speed V_Act to 0 and the running distance to S2, Dec1 = V_Act 2 / (2*S2);

[0049] Step 10: According to the deceleration Dec1, control the inverter to decelerate the motor in JOG motion until the speed is reduced to 0;

[0050] Step 11: Compare whether the distance S2 from the target position P0 is less than the positioning accuracy OffSet;

[0051] If S2≤OffSet, jump to step 12;

[0052] If S2>OffSet, jump to step 8 to continue the deceleration process control;

[0053] Step 12: After completing positioning, stop moving.

[0054] Preferably, the maximum speed V_Max in step 3 is calculated as follows: V_Max=2*S0*Acc0*Dec0 / (Acc0+Dec0);

[0055] Preferably, in step 4, the basis for obtaining the positioning speed V1 is:

[0056] If the maximum speed V_Max> target speed V0, then the positioning speed V1=target speed V0;

[0057] If the maximum speed V_Max≤target speed V0, the positioning speed V1=maximum speed V_Max.

[0058] A frequency converter positioning system based on commercial vehicle battery swap station, such as Figure 2 As shown, it includes a PLC, a frequency converter, an encoder and a motor. The PLC is responsible for obtaining the position parameters of the encoder and receiving the status data of the frequency converter. The PLC sends control parameters to the frequency converter, so that the frequency converter controls the motor to perform corresponding operations, so as to realize a frequency converter positioning method based on a commercial vehicle battery swap station.

[0059] Preferably, the PLC is a Siemens 1511 controller, the frequency converter is a Siemens G120C frequency converter, the encoder is a multi-turn absolute encoder, and the motor is a three-phase asynchronous reduction motor.

[0060] Preferably, the PCL uses Profinet communication to communicate with the frequency converter and the frequency converter respectively.

[0061] In the description of the present invention, it should be noted that the directions or positional relationships indicated by terms such as "center", "up", "down", "left", "right", "vertical", "horizontal", "front" and "back" are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention.

[0062] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "set" should be understood in a broad sense, for example, they can be fixedly connected or set, or detachably connected or set, or integrally connected or set. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0063] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. It should be pointed out that a person skilled in the art can make several improvements and modifications without departing from the technical principles of the present invention, and these improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A method for locating a frequency converter in a commercial vehicle battery swap station, characterized in that: The following steps are involved: Step 1: trigger positioning, set target parameters, including target position P0, target speed V0, acceleration Acc0, deceleration Dec0 and positioning accuracy OffSet, and obtain the actual position Pe_Act of the encoder; Step 2: Calculate the distance S0 between the actual position Pe_Act and the target position P0, S0 = P0 - Pe_Act; Step 3: Calculate the maximum speed V_Max of the motor based on the triangle positioning theory; Step 4: By comparing the target speed V0 and the maximum speed V_Max, the minimum speed is obtained as the positioning speed V1; Step 5: According to the parameters of positioning speed V1, acceleration Acc0 and deceleration Dec0, control the inverter to make the motor perform JOG motion; Step 6: Calculate the distance S1 required to reduce the current running speed V_Act to 0 according to the deceleration Dec0. The calculation formula is S1 = V_Act 2 / (2*Dec0); Step 7: Compare S1 and S0, and determine whether to execute deceleration control or continue acceleration and constant speed control; If S1 ≥ S0, jump to step 8 to execute deceleration process control; If S1<S0, return to the third step to continue to execute the acceleration uniform speed process control; Step 8: Calculate the distance S2 between the current actual position Pe_Act and the target position P0, S2 = P0 - Pe_Act; Step 9: Calculate the deceleration Dec1 required to reduce the current running speed V_Act to 0 and the running distance to S2, Dec1 = V_Act 2 / (2*S2); Step 10: According to the deceleration Dec1, control the inverter to decelerate the motor in JOG motion until the speed is reduced to 0; Step 11: Compare whether the distance S2 from the target position P0 is less than the positioning accuracy OffSet; If S2≤OffSet, jump to step 12; If S2>OffSet, jump to step 8 to continue the deceleration process control; Step 12: After completing positioning, stop moving.

2. A method for locating a frequency converter based on a commercial vehicle battery swap station according to claim 1, characterized in that: The maximum speed V_Max calculation formula of step 3 is: V_Max=2*S0*Acc0*Dec0 / (Acc0+Dec0).

3. The method for locating a frequency converter based on a commercial vehicle battery swap station according to claim 1 is characterized in that: In step 4, the basis for obtaining the positioning speed V1 is: If the maximum speed V_Max> target speed V0, then the positioning speed V1=target speed V0; If the maximum speed V_Max≤target speed V0, the positioning speed V1=maximum speed V_Max.

4. A frequency converter positioning system based on a commercial vehicle battery swap station, characterized in that: It includes a PLC, a frequency converter, an encoder and a motor. The PLC is responsible for obtaining the position parameters of the encoder and receiving the status data of the frequency converter. The PLC sends control parameters to the frequency converter, so that the frequency converter controls the motor to perform corresponding operations, so as to realize a frequency converter positioning method based on a commercial vehicle battery swap station as described in any one of claims 1-3.

5. The inverter positioning system based on a commercial vehicle battery swap station according to claim 4 is characterized in that: The encoder is a multi-turn absolute encoder, and the motor is a three-phase asynchronous reduction motor.

6. The inverter positioning system based on a commercial vehicle battery swap station according to claim 4 is characterized in that: The PCL is connected to the frequency converter and the frequency converter by Profinet communication.

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