A mixing drum control method and related device

Abstract

The present application relates to the technical field of mixer truck control, and in particular to a mixer drum control method and related devices, comprising: receiving a stop instruction for the mixer drum, determining a candidate pre-torque of a motor based on a pre-stop speed of the mixer drum immediately before the stop, an actual mass of concrete in the mixer drum, a maximum cross-sectional radius of the mixer drum, and a speed ratio of a reducer, and selecting the maximum value of the candidate pre-torque and the pre-stop torque of the motor corresponding to the mixer drum immediately before the stop as the target pre-torque of the motor; after controlling the speed of the motor to be 0, switching the control mode of the motor from speed control to torque control; when it is detected that the mixer drum rotates in the reverse direction, controlling the motor to rotate in the forward direction, wherein the forward rotation control is performed in the following manner: if the reverse speed of the motor is greater than a reverse speed threshold, using the target pre-torque as the forward torque of the motor, and sending the forward torque to a motor controller so that the motor controller controls the motor to rotate with the forward torque.

Description

Technical Field

[0001] The present application relates to the technical field of mixer truck control, and in particular to a mixer drum control method and related devices. Background Art

[0002] With the advancement and development of technology, new energy has come into people's view with its own environmental protection, and new energy electric mixer trucks have also emerged. New energy electric mixer trucks adopt electric upper layout.

[0003] In the prior art, the electric mixer drum control technology generally adopts a single motor speed control. During the start-up feeding process, multiple different forward target speed gears are set. The operator can adjust the mixer drum speed according to the loading situation to keep the concrete in a fully mixed state during transportation. When unloading is required, the machine needs to be stopped first. Specifically, the stop button is pressed first, and the mixer drum is waited for to stop completely and stably from a fast mixing state before unloading.

[0004] However, during the shutdown process, the mixing drum shakes greatly from the rapid stirring state to the completely stopped stable state, and the waiting time is long, which will affect the overall efficiency of the mixing drum. Summary of the invention

[0005] The embodiments of the present application provide a mixing drum control method and related devices to reduce the shaking degree and shaking time of the mixing drum during shutdown.

[0006] The specific technical solutions provided by the embodiments of this application are as follows:

[0007] In a first aspect, a mixing drum control method is provided, the method comprising:

[0008] receiving a stop instruction for the mixing drum, determining a candidate pre-torque of the motor based on the pre-stop speed of the mixing drum immediately before the stop, the actual mass of concrete in the mixing drum, the maximum cross-sectional radius of the mixing drum, and the speed ratio of the reducer, and selecting the maximum value of the candidate pre-torque and the pre-stop torque of the motor corresponding to the mixing drum immediately before the stop as the target pre-torque of the motor;

[0009] After the motor speed is controlled to 0, the motor control mode is switched from speed control to torque control;

[0010] When the mixing drum is detected to be rotating in the reverse direction, the motor is controlled to rotate in the forward direction, wherein the forward rotation control is performed in the following manner: if the reverse speed of the motor is greater than the reverse speed threshold, the target pre-torque is used as the forward torque of the motor, and the forward torque is sent to the motor controller so that the motor controller controls the motor to rotate with the forward torque.

[0011] In a possible embodiment, after taking the target pre-torque as the positive torque of the motor and sending the positive torque to the motor controller so that the motor controller controls the motor to rotate with the positive torque, the method further includes:

[0012] If the reverse speed of the motor continues to increase, the forward torque continues to increase, wherein the increased forward torque is less than or equal to the motor external characteristic;

[0013] If the reverse speed of the motor continues to decrease, the forward torque continues to decrease, and when the distance between the reverse speed and the 0 speed is less than the distance threshold, the forward torque is set to 0.

[0014] Through the above method, torque fuzzy control is performed to weaken or even eliminate the tendency of the mixing drum to shake, reduce the degree and duration of shaking during the mixing drum shutdown process, and improve the robustness of the system.

[0015] In one possible embodiment, the forward torque is determined based on a torque distribution table, a reverse speed of the motor, a speed of the mixing drum before shutdown, and an actual mass of concrete in the mixing drum;

[0016] The torque distribution table is used to store the motor distribution torques corresponding to each current speed of the motor and each speed before shutdown when the maximum load of concrete is loaded in the mixing drum.

[0017] Through the above method, the current accurate forward torque of the mixing drum can be quickly obtained.

[0018] In a possible embodiment, when it is detected that the mixing drum rotates in the reverse direction, after the motor is controlled to rotate in the forward direction, the method further includes:

[0019] When the forward rotation of the mixing drum is detected, the motor is controlled to rotate in the reverse direction, wherein the reverse rotation control is performed in the following manner: if the forward speed of the motor is greater than the forward speed threshold, the target pre-torque is used as the reverse torque of the motor, and the reverse torque is sent to the motor controller so that the motor controller controls the motor to rotate with the reverse torque.

[0020] Through the above method, the forward and reverse movements of the mixing drum are comprehensively considered, and when the concrete performs multiple back-and-forth pendulum movements in the drum, the shaking degree and shaking time of the mixing drum can be reduced to the greatest extent.

[0021] In a possible embodiment, after taking the target pre-torque as the reverse torque of the motor and sending the reverse torque to the motor controller so that the motor controller controls the motor to rotate with the reverse torque, the method further includes:

[0022] If the forward speed of the motor continues to increase, the reverse torque continues to increase, wherein the increased reverse torque is less than or equal to the motor external characteristic;

[0023] If the forward speed of the motor continues to decrease, the reverse torque continues to decrease, and when the distance between the forward speed and the 0 speed is less than the distance threshold, the reverse torque is set to 0.

[0024] Through the above method, torque fuzzy control is performed to weaken or even eliminate the tendency of the mixing drum to shake, reduce the degree and duration of shaking during the mixing drum shutdown process, and improve the robustness of the system.

[0025] In a second aspect, the present application provides a mixing drum control device, the device comprising:

[0026] a determination module, configured to receive a stop instruction for a mixing drum, determine a candidate pre-torque of the motor based on a pre-stop speed of the mixing drum immediately before the stop, an actual mass of concrete in the mixing drum, a maximum cross-sectional radius of the mixing drum, and a speed ratio of the reducer, and select a maximum value between the candidate pre-torque and a pre-stop torque of the motor corresponding to the mixing drum immediately before the stop as a target pre-torque of the motor;

[0027] A switching module is used to switch the control mode of the motor from speed control to torque control after the speed of the motor is controlled to 0;

[0028] The processing module is used to control the motor to rotate in the forward direction when the reverse rotation of the mixing drum is detected, wherein the forward rotation control is performed in the following manner: if the reverse speed of the motor is greater than the reverse speed threshold, the target pre-torque is used as the forward torque of the motor, and the forward torque is sent to the motor controller so that the motor controller controls the motor to rotate with the forward torque.

[0029] In a possible embodiment, when determining the target pre-torque of the motor based on the pre-stop speed of the mixing drum immediately before the stop and the pre-stop torque of the motor corresponding to the mixing drum, the determination module is further used to:

[0030] Determine a candidate pre-torque of the motor based on the pre-stop speed of the mixing drum, the actual mass of concrete in the mixing drum, the maximum cross-sectional radius of the mixing drum, and the speed ratio of the reducer;

[0031] The maximum value between the candidate pre-torque and the torque before shutdown is selected as the target pre-torque.

[0032] In a possible embodiment, after the target pre-torque is used as the positive torque of the motor and the positive torque is sent to the motor controller so that the motor controller controls the motor to rotate with the positive torque, the processing module is further used to:

[0033] If the reverse speed of the motor continues to increase, the forward torque continues to increase, wherein the increased forward torque is less than or equal to the motor external characteristic;

[0034] If the reverse speed of the motor continues to decrease, the forward torque continues to decrease, and when the distance between the reverse speed and the 0 speed is less than the distance threshold, the forward torque is set to 0.

[0035] In one possible embodiment, the forward torque is determined based on a torque distribution table, a reverse speed of the motor, a speed of the mixing drum before shutdown, and an actual mass of concrete in the mixing drum;

[0036] The torque distribution table is used to store the motor distribution torques corresponding to each current speed of the motor and each speed before shutdown when the maximum load of concrete is loaded in the mixing drum.

[0037] In a possible embodiment, when it is detected that the mixing drum rotates in the reverse direction, after the motor is controlled to rotate in the forward direction, the processing module is further used to:

[0038] When the forward rotation of the mixing drum is detected, the motor is controlled to rotate in the reverse direction, wherein the reverse rotation control is performed in the following manner: if the forward speed of the motor is greater than the forward speed threshold, the target pre-torque is used as the reverse torque of the motor, and the reverse torque is sent to the motor controller so that the motor controller controls the motor to rotate with the reverse torque.

[0039] In a possible embodiment, after the target pre-torque is used as the reverse torque of the motor and the reverse torque is sent to the motor controller so that the motor controller controls the motor to rotate with the reverse torque, the processing module is further configured to:

[0040] If the forward speed of the motor continues to increase, the reverse torque continues to increase, wherein the increased reverse torque is less than or equal to the motor external characteristic;

[0041] If the forward speed of the motor continues to decrease, the reverse torque continues to decrease, and when the distance between the forward speed and the 0 speed is less than the distance threshold, the reverse torque is set to 0.

[0042] According to a third aspect, an electronic device is provided, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the steps of any one of the methods described in the first aspect are implemented.

[0043] According to a fourth aspect, a computer-readable storage medium is provided, on which a computer program is stored, and when the computer program is executed by a processor, the steps of the method described in any one of the first aspects are implemented.

[0044] In a fifth aspect, the present application provides a new energy vehicle on which a mixing drum control device is stored, and the steps of the method described in any one of the first aspects are executed.

[0045] In an embodiment of the present application, a stop command for a mixing drum is received, and a candidate pre-torque of the motor is determined based on the pre-stop speed of the mixing drum just before the stop, the actual mass of concrete in the mixing drum, the maximum cross-sectional radius of the mixing drum, and the speed ratio of the reducer, and the maximum value of the candidate pre-torque and the pre-stop torque of the motor corresponding to the mixing drum just before the stop is selected as the target pre-torque of the motor, and then after the speed of the motor is controlled to be 0, the control mode of the motor is switched from speed control to torque control, and then when the reverse rotation of the mixing drum is detected, the motor is controlled to rotate in the forward direction, wherein the forward rotation control is performed in the following manner: if the reverse speed of the motor is greater than the reverse speed threshold, the target pre-torque is used as the forward torque of the motor, and the forward torque is sent to the motor controller so that the motor controller controls the motor to rotate with the forward torque. In this way, through the pre-shutdown speed and pre-shutdown torque, the target pre-torque that can effectively reduce the increasing trend of the shaking of the mixing drum can be accurately estimated. By using this target pre-torque, the repeated shaking of the mixing drum can be quickly eliminated, and the mixing drum can quickly reach a stable state, reducing the degree and time of shaking during the shutdown process. At the same time, the control scheme that combines motor speed control and torque control can minimize the shaking of the mixing drum during the shutdown process. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 A schematic diagram of an electric mixing drum provided in an embodiment of the present application;

[0047] Figure 2 A schematic diagram of a new energy electric mixer truck in an embodiment of the present application;

[0048] Figure 3 This is a flow chart of an implementation of a mixing drum control method provided in an embodiment of the present application;

[0049] Figure 4 A schematic diagram of a force analysis of constant speed operation in an embodiment of the present application;

[0050] Figure 5 A schematic diagram of the force analysis of the shutdown and fall-back process in the embodiment of the present application;

[0051] Figure 6 A schematic diagram of a torque distribution table in an embodiment of the present application;

[0052] Figure 7 Another schematic diagram of a flow chart of a mixing drum control method in an embodiment of the present application;

[0053] Figure 8 This is a structural schematic diagram of a mixing drum control device in an embodiment of the present application;

[0054] Fig. 9 Schematic diagram of the structure of an electronic device in an embodiment of the present application. DETAILED DESCRIPTION

[0055] In order to make the purpose, technical scheme and advantages of the present application clearer, the technical scheme in the embodiment of the present application will be clearly and completely described below in conjunction with the drawings in the embodiment of the present application. Obviously, the described embodiment is only a part of the embodiment of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of the present application. In the absence of conflict, the embodiments in the present application and the features in the embodiments can be arbitrarily combined with each other. In addition, although the logical order is shown in the flow chart, in some cases, the steps shown or described can be performed in an order different from that here.

[0056] The terms "first" and "second" in the specification and claims of the present application and the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order. In addition, the term "comprising" and any of their variations are intended to cover non-exclusive protection. For example, a process, method, system, product or device comprising a series of steps or units is not limited to the listed steps or units, but optionally also includes steps or units that are not listed, or optionally also includes other steps or units inherent to these processes, methods, products or devices. "Multiple" in the present application can mean at least two, for example, two, three or more, and the embodiments of the present application are not limited.

[0057] The following is a description of exemplary embodiments of the present application in conjunction with the accompanying drawings, including various details of the embodiments of the present application to facilitate understanding, which should be considered as merely exemplary. Therefore, those of ordinary skill in the art should recognize that various changes and modifications can be made to the embodiments described herein without departing from the scope of the present application. Similarly, for the sake of clarity and conciseness, the description of well-known functions and structures is omitted in the following description. It should be noted that in the embodiments of the present application, certain software, components, models and other existing solutions in the industry may be mentioned, which should be considered as exemplary, and their purpose is only to illustrate the feasibility of the implementation of the technical solution of the present application, but it does not mean that the applicant has or will necessarily use the solution.

[0058] The following is a brief introduction to the design concept of the embodiment of the present application:

[0059] The chassis of traditional mixer trucks uses an engine, and the upper body uses a hydraulic pump and a reducer drive mode. This mode consumes a lot of fuel and causes serious environmental pollution. At present, pure electric mixer trucks (new energy electric mixer trucks) and hybrid mixer trucks that can reduce carbon emissions have emerged. Specifically, pure electric mixer trucks use a pure electric chassis to drive the vehicle, and the upper body uses a motor and a reducer layout. The chassis of hybrid mixer trucks uses an engine to drive, and the upper body uses a pure electric layout of batteries, motors and reducers. Both methods use electric upper body layouts.

[0060] See also Figure 1 , which is a schematic diagram of an electric mixing drum provided in an embodiment of the present application, including a mixing drum 101 , a reducer 102 , a motor 103 , and a battery 104 .

[0061] In the prior art, electric mixing drum control technology generally adopts a single motor speed control. During the start-up and feeding process, a plurality of different forward target speed gears are set. The operator can adjust the mixing drum speed according to the loading conditions, so that the concrete is in a fully mixed state during transportation. When unloading is required, it is necessary to first perform a shutdown operation. Specifically, press the stop button first, wait for the mixing drum to change from a fast mixing state to a completely stopped stable state, and then perform the unloading operation. During the unloading process, a plurality of different reverse target speed gears are also set, and the operator adjusts the unloading speed according to the actual situation.

[0062] However, during the shutdown process, the mixing drum shakes greatly from the rapid mixing state to the completely stopped and stable state, which can easily cause safety problems for the mixer truck. At the same time, the waiting time is long, which can easily cause the risk of concrete solidification and affect the overall efficiency of the mixing drum.

[0063] In view of this, in an embodiment of the present application, a mixing drum control method and related devices are provided, which receive a stop command for the mixing drum, determine the candidate pre-torque of the motor based on the pre-stop speed of the mixing drum just before the stop, the actual mass of concrete in the mixing drum, the maximum cross-sectional radius of the mixing drum, and the speed ratio of the reducer, and select the maximum value of the candidate pre-torque and the pre-stop torque of the motor corresponding to the mixing drum just before the stop as the target pre-torque of the motor; after controlling the speed of the motor to 0, switch the control mode of the motor from speed control to torque control; then when it is detected that the mixing drum is rotating in the opposite direction, control the motor to rotate in the forward direction, wherein the forward rotation control is performed in the following manner: if the reverse speed of the motor is greater than the reverse speed threshold, use the target pre-torque as the forward torque of the motor, and send the forward torque to the motor controller so that the motor controller controls the motor to rotate with the forward torque. In this way, the target pre-torque that can effectively reduce the increasing trend of the shaking of the mixer drum can be accurately estimated through the pre-stop speed and pre-stop torque, and the repeated shaking of the mixer drum can be quickly eliminated by using the target pre-torque, so that the mixer drum can quickly reach a stable state, reducing the shaking degree and shaking time during the shutdown process. At the same time, the control scheme combining motor speed control and torque control can minimize the shaking of the mixer drum during the shutdown process. Thereby, the overall efficiency of the mixer drum is improved and the user experience is enhanced.

[0064] The preferred embodiments of the present application are described below in conjunction with the drawings in the specification. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present application, and are not used to limit the present application. In addition, the embodiments of the present application and the features in the embodiments may be combined with each other if there is no conflict.

[0065] See also Figure 2 As shown, it is a schematic diagram of a new energy electric mixer truck in an embodiment of the present application. The new energy electric mixer truck 200 includes a mixing drum 201, a reducer 202, a motor 203, a motor controller 204, and a control unit 205. Among them, the motor 203 is used to drive the mixing drum 201 to rotate, and the motor controller 204 is used to control the rotation of the motor 203. The control unit 205 is used to receive a shutdown instruction for the mixing drum, based on the pre-stop speed of the mixing drum before the stop, the actual mass of the concrete in the mixing drum, the maximum cross-sectional radius of the mixing drum, and the speed ratio of the reducer, determine the candidate pre-torque of the motor, and select the maximum value of the candidate pre-torque and the pre-stop torque of the motor corresponding to the mixing drum before the stop as the target pre-torque of the motor, and after controlling the speed of the motor to 0, switch the control mode of the motor from speed control to torque control, and when the mixing drum is detected to rotate in the opposite direction, the motor is controlled to rotate in the forward direction.

[0066] See also Figure 3As shown, it is an implementation flow chart of a mixing drum control method provided in an embodiment of the present application, and the specific implementation process of the method is as follows:

[0067] Step 30: Receive a stop command for the mixing drum, determine the candidate pre-torque of the motor based on the pre-stop speed of the mixing drum just before the stop, the actual mass of concrete in the mixing drum, the maximum cross-sectional radius of the mixing drum, and the speed ratio of the reducer, and select the maximum value of the candidate pre-torque and the pre-stop torque of the motor corresponding to the mixing drum just before the stop as the target pre-torque of the motor.

[0068] The stop command is used to instruct the mixer drum to stop, and the moment before the stop is the moment when the mixer drum stop button is pressed.

[0069] In an embodiment of the present application, when the operating object presses the stop button of the mixing drum, a stop command for the mixer is triggered. When the stop command is received, the pre-stop speed of the mixing drum and the pre-stop torque of the motor corresponding to the mixing drum are recorded, and based on the pre-stop speed of the mixing drum just before the stop, the actual mass of concrete in the mixing drum, the maximum cross-sectional radius of the mixing drum, and the speed ratio of the reducer, the candidate pre-torque of the motor is determined, and the maximum value of the candidate pre-torque and the pre-stop torque of the motor corresponding to the mixing drum just before the stop is selected as the target pre-torque of the motor.

[0070] In the embodiment of the present application, the candidate pre-torque calculation formula of the motor can be expressed as:

[0071]

[0072] Among them, m is the actual mass of concrete in the mixing drum, ω is the speed of the mixing drum before shutdown, r is the maximum cross-sectional radius of the mixing drum, and i is the speed ratio of the reducer.

[0073] In the embodiment of the present application, the calculation formula of the candidate pre-torque of the motor is inferred based on the stress state of the concrete before and after the mixing drum is stopped. The reasoning of the calculation formula for obtaining the candidate pre-torque is described below:

[0074] The power source of the entire upper device comes from the battery. The motor converts electrical energy into mechanical energy, driving the reducer to drive the mixing drum. Since concrete is a non-homogeneous three-phase body, when the mixing drum is working, the concrete in the mixing drum is driven along the circumference by the drum wall due to the friction force of the drum wall.

[0075] When the mixing drum is running at a constant speed, the state of the concrete in the mixing drum is relatively stable. During the constant speed operation of the concrete, the stress analysis of the concrete is as follows: Figure 4 As shown, the shaded part in the figure is the whole concrete, e1 is the normal direction of gravity, and e2 is the horizontal direction perpendicular to gravity.

[0076] according to Figure 4 The force analysis in , we get: .

[0077] Where, G = m·g·cosα, F f =m·r·ω 2 , m is the actual mass of concrete in the mixing drum, F f is the circumferential friction force exerted on the concrete by the wall of the mixing drum, α is the inclination angle of the mixing drum, ω is the speed of the mixing drum at constant speed, and r is the maximum cross-sectional radius of the mixing drum.

[0078] In summary, the angle between the circumferential friction force and the gravity is obtained .

[0079] When the mixing drum is running at a constant speed, it stops suddenly, the motor controls the mixing drum speed to 0, and the circumferential friction force F of the mixing drum on the concrete f disappear, the concrete falls back under the action of gravity, and in the process of falling back, the concrete is affected by its own gravity G and centrifugal force F c1 and the friction force F between the cylinder wall f1 During the concrete stop and fall process, the concrete stress analysis is as follows: Figure 5 As shown, the shaded part in the figure is the whole concrete, e1 is the normal direction of gravity, and e2 is the horizontal direction perpendicular to gravity.

[0080] The circumferential tangential force F of concrete on the mixing drum t The mixing drum is reversed, and the circumferential tangential force F of the concrete on the mixing drum t = F f1 ≤G·cosθ, tangential torque generated by concrete: T t = F t ·r.

[0081] Therefore, in order to restrain the circumferential tangential force, the theoretical maximum pre-torque of the motor satisfies: , where i is the speed ratio of the reducer. Substituting in: , the theoretical maximum pre-torque of the motor is taken as the candidate pre-torque.

[0082] In this way, by analyzing the rotation speed of the mixing drum, the motor torque, and the operating status of the concrete in the drum before and after the mixing drum is stopped, a calculation formula for the candidate pre-torque is obtained, and the candidate pre-torque that can effectively reduce the increasing trend of the shaking of the mixing drum can be accurately obtained.

[0083] In the embodiment of the present application, the candidate pre-torques are compared with the torque before shutdown, and the maximum of the two is selected as the target pre-torque.

[0084] In the embodiment of the present application, the target pre-torque of the motor can be expressed as:

[0085]

[0086] Among them, T max is the candidate pre-torque, T q is the torque of the motor before stopping.

[0087] Optionally, in the embodiment of the present application, the torque before shutdown T q satisfy: , where η0 is the transmission system efficiency, F f is the circumferential friction force, r is the maximum cross-sectional radius of the mixing drum, and i is the speed ratio of the reducer.

[0088] In this way, not only is the analysis conducted from the mechanical perspective of the concrete itself, i.e. the candidate pre-torque, but the operating status of the entire tank is also taken into consideration, i.e. the torque before shutdown, ensuring that the establishment of the target pre-torque can effectively reduce the increasing trend of shaking of the mixing drum.

[0089] Step 31: After the motor speed is controlled to 0, the motor control mode is switched from speed control to torque control.

[0090] In the embodiment of the present application, the speed of the motor is controlled to be 0, and then after the speed of the motor is controlled to be 0, the control mode of the motor is switched from speed control to torque control.

[0091] In this way, the control scheme combining motor speed control and torque control can minimize the shaking of the mixing drum during shutdown.

[0092] Step 32: When the mixing drum is detected to be rotating in the reverse direction, the motor is controlled to rotate in the forward direction, wherein the forward rotation control is performed in the following manner: if the reverse speed of the motor is greater than the reverse speed threshold, the target pre-torque is used as the forward torque of the motor, and the forward torque is sent to the motor controller so that the motor controller controls the motor to rotate with the forward torque.

[0093] Among them, the reverse speed of the motor is less than or equal to the reverse speed threshold, which indicates that the mixing drum shakes less, and the reverse speed of the motor is greater than the reverse speed threshold, which indicates that the mixing drum shakes more and the motor torque needs to be controlled to suppress the shaking of the mixing drum.

[0094] In the embodiment of the present application, after the motor speed is controlled to be 0, the mixing drum rotates in the reverse direction with the motor, and the current motor speed is detected by the speed sensor. When the motor is identified to be rotating in the reverse direction, it is determined that the mixing drum is rotating in the reverse direction. When the mixing drum is detected to be rotating in the reverse direction, the motor is controlled to rotate in the forward direction, wherein the forward rotation control is performed in the following manner: determine whether the reverse speed of the motor is greater than the reverse speed threshold, and if so, use the target pre-torque as the forward torque of the motor, and send the forward torque to the motor controller so that the motor controller controls the motor to rotate with the forward torque.

[0095] In addition, it is worth noting that, since the reverse speed of the motor and the reverse speed of the mixing drum can be converted to each other through the speed ratio of the reducer, in the embodiment of the present application, the reverse speed of the mixing drum and the reverse speed threshold corresponding to the mixing drum can also be compared. In the embodiment of the present application, there is no restriction on the use of the reverse speed of the motor and the reverse speed of the mixing drum. If the reverse speed of the mixing drum is greater than the reverse speed threshold corresponding to the mixing drum, the target pre-torque is used as the forward torque of the motor, and the forward torque is sent to the motor controller so that the motor controller controls the motor to rotate with the forward torque.

[0096] Further, in the embodiment of the present application, the target pre-torque is used as the forward torque of the motor, and the forward torque is sent to the motor controller, so that the motor controller controls the motor to rotate with the forward torque, and the shaking state of the mixing drum can also be monitored and adjusted. Specifically, the forward torque is adjusted according to the reverse speed of the motor, so that the motor controller controls the motor to rotate with the adjusted forward torque. The adjustment of the forward torque includes the following two situations:

[0097] Case 1: When the reverse speed of the motor continues to increase, the forward torque continues to increase.

[0098] The increased positive torque is less than or equal to the motor external characteristic, where the motor external characteristic is the torque determined based on the physical characteristics of the motor and represents the maximum capacity of the motor.

[0099] Case 2: When the reverse speed of the motor continues to decrease, the forward torque continues to decrease.

[0100] Furthermore, in the embodiment of the present application, when the distance between the reverse speed and the 0 speed is less than the distance threshold, the forward torque is set to 0.

[0101] In this way, the speed stability after the target pre-torque is applied when the mixer drum is stopped is controlled by torque fuzzy control, which weakens or even eliminates the tendency of the mixer drum to shake. This not only reduces the degree and duration of shaking during the mixer drum shutdown process, but also improves the robustness of the system.

[0102] In the embodiment of the present application, the increased or decreased forward torque is determined based on the torque distribution table, the reverse speed of the motor, the speed of the mixing drum before shutdown, and the actual mass of the concrete in the mixing drum.

[0103] The torque distribution table is used to store the motor distribution torque corresponding to each current speed and each speed before shutdown when the maximum load of concrete is loaded in the mixing drum. The torque distribution table can be in the form of a two-dimensional lookup map, which is obtained through experience and data fitting. Figure 6 As shown, it is a schematic diagram of the torque distribution table in the embodiment of the present application, wherein the independent variable one is the speed of the mixing drum before shutdown, the independent variable two is the current speed of the motor, each line represents a different speed of the mixing drum before shutdown, the vertical axis is the current speed of the motor, and the horizontal axis is the motor allocated torque.

[0104] In addition, it is worth noting that since the current speed of the motor and the current speed of the mixing drum can be converted to each other through the speed ratio of the reducer, in the embodiment of the present application, the torque distribution table can also be used to store the current speed of each mixing drum and the motor distribution torque corresponding to each speed before shutdown when the maximum load of concrete is loaded in the mixing drum. This is not limited in the embodiment of the present application.

[0105] Optionally, in the embodiment of the present application, a possible embodiment is provided for determining the increased or decreased forward torque, and the specific steps are as follows:

[0106] Step A1: query the torque distribution table to determine the initial distribution torque that matches the current reverse speed of the motor and the speed of the mixer drum before shutdown.

[0107] For example, assuming that the current reverse speed of the motor is 300 rpm and the speed of the mixer drum before shutdown is 16 rpm, query Figure 6 The torque distribution table shown in the figure shows that the initial distribution torque is 1 Nm, which matches the current reverse speed of the motor of 300 rpm and the pre-stop speed of the mixing drum of 16 rpm.

[0108] Step A2: Based on the actual mass of concrete in the mixing drum and the maximum mass of concrete that can be loaded in the mixing drum, the initial distribution torque is adjusted to obtain the target distribution torque corresponding to the actual mass, and the positive torque is adjusted to the target distribution torque.

[0109] The actual mass may be obtained by means of a mass sensor or the like, which is not limited in the embodiments of the present application.

[0110] In the embodiment of the present application, the target distributed torque can be obtained by multiplying the target mass coefficient by the initial distributed torque.

[0111] The target mass coefficient is obtained based on the actual mass of concrete currently loaded in the mixing drum and the maximum mass of concrete that can be loaded in the mixing drum. The target mass coefficient can be expressed as: η1=M / M max , where M is the actual mass of concrete in the mixing drum, M max The maximum load of concrete that the mixing drum can load.

[0112] For example, if the initial distributed torque is 1 Nm and the target mass coefficient is 1 / 2, the target distributed torque is 1 / 2 Nm.

[0113] In this way, the torque distribution table is designed based on the maximum load mass of concrete that can be loaded in the mixing drum. When the mass of concrete in the drum changes, the torque in the torque distribution table can be adjusted according to the mass coefficient. Quick and smooth start and stop can be achieved under different loading masses of the mixing drum, ensuring accurate target adjustment torque without the need to query too many distribution tables or perform a large amount of torque calibration work, thereby reducing the calibration workload of the torque distribution table.

[0114] Furthermore, since concrete relies on the friction with the drum wall to do work to offset the gravitational potential energy of its inertia and thus reach a stable state, the concrete will perform multiple back-and-forth pendulum motions in the mixing drum. After the first reverse rotation of the mixing drum is completed, the mixing drum will begin its first forward rotation.

[0115] In an embodiment of the present application, when the forward rotation of the mixing drum is detected, the motor is controlled to rotate in the reverse direction, wherein the reverse rotation control is performed in the following manner: if the forward speed of the motor is greater than the forward speed threshold, the target pre-torque is used as the reverse torque of the motor, and the reverse torque is sent to the motor controller so that the motor controller controls the motor to rotate with the reverse torque.

[0116] Among them, the forward speed of the motor is less than or equal to the forward speed threshold, which indicates that the mixing drum shakes less. The forward speed of the motor is greater than the forward speed threshold, which indicates that the mixing drum shakes more and the motor torque needs to be controlled to suppress the shaking of the mixing drum. The forward speed threshold and the reverse speed threshold are equal in size and opposite in direction.

[0117] In the embodiment of the present application, the current speed of the motor is detected by the speed sensor, and when the forward rotation of the motor is identified, the mixing drum is determined to be rotating forward. When the forward rotation of the mixing drum is detected, the motor is controlled to rotate in the reverse direction, wherein the reverse rotation control is performed in the following manner: it is determined whether the forward speed of the motor is greater than the forward speed threshold, and if so, the target pre-torque is used as the reverse torque of the motor, and the reverse torque is sent to the motor controller, so that the motor controller controls the motor to rotate with the reverse torque.

[0118] In this way, when the concrete performs multiple pendulum motions back and forth in the drum, the forward and reverse motions of the mixing drum are comprehensively considered. By adopting the target pre-torque when the speed is greater than the speed threshold, the shaking degree and shaking time of the mixing drum can be minimized to the greatest extent.

[0119] In addition, it is worth noting that, since the forward speed of the motor and the forward speed of the mixing drum can be converted to each other through the speed ratio of the reducer, in the embodiment of the present application, the forward speed of the mixing drum and the forward speed threshold corresponding to the mixing drum can also be compared. In the embodiment of the present application, there is no restriction on the use of the forward speed of the motor and the forward speed of the mixing drum. If the forward speed of the mixing drum is greater than the forward speed threshold corresponding to the mixing drum, the target pre-torque is used as the reverse torque of the motor, and the reverse torque is sent to the motor controller so that the motor controller controls the motor to rotate with the reverse torque.

[0120] Further, in the embodiment of the present application, after the target pre-torque is used as the reverse torque of the motor and the reverse torque is sent to the motor controller so that the motor controller controls the motor to rotate with the reverse torque, the reverse torque can also be adjusted according to the forward speed of the motor so that the motor controller controls the motor to rotate with the adjusted reverse torque. The adjustment of the reverse torque includes the following two situations:

[0121] Case 1: When the forward speed of the motor continues to increase, the reverse torque continues to increase.

[0122] The increased reverse torque is less than or equal to the motor external characteristic.

[0123] Case 2: When the forward speed of the motor continues to decrease, the reverse torque continues to decrease.

[0124] Furthermore, in the embodiment of the present application, when the distance between the forward speed and the 0 speed is less than a distance threshold, the reverse torque is set to 0.

[0125] In this way, the speed stability after the target pre-torque is applied when the mixer drum is stopped is controlled by torque fuzzy control, which weakens or even eliminates the tendency of the mixer drum to shake. This not only reduces the degree and duration of shaking during the mixer drum shutdown process, but also improves the robustness of the system.

[0126] In the embodiment of the present application, the increased or decreased reverse torque is determined based on the torque distribution table, the forward speed of the motor, the speed of the mixing drum before shutdown, and the actual mass of the concrete in the mixing drum.

[0127] Optionally, in the embodiment of the present application, a possible embodiment is provided for determining the increased or decreased reverse torque, and the specific steps are as follows:

[0128] Step B1: query the torque distribution table to determine the initial distribution torque that matches the current forward speed of the motor and the speed of the mixer drum before shutdown.

[0129] For example, assuming that the current forward speed of the motor is 300 rpm and the speed of the mixer drum before shutdown is 16 rpm, query Figure 6 The torque distribution table shown in the figure shows that the initial distribution torque is -1Nm, which matches the current forward speed of the motor of 300rpm and the pre-stop speed of the mixing drum of 16rpm.

[0130] Step B2: Based on the actual mass of concrete in the mixing drum and the maximum mass of concrete that the mixing drum can load, the initial distribution torque is adjusted to obtain the target distribution torque corresponding to the actual mass, and the reverse torque is adjusted to the target distribution torque.

[0131] For example, if the initial distributed torque is -1 Nm and the target mass coefficient is 1 / 2, the target distributed torque is -1 / 2 Nm.

[0132] Based on the above embodiments, see Figure 7 FIG. 1 is another flow chart of the mixing drum control method in the embodiment of the present application, which specifically includes:

[0133] Step 70: Start.

[0134] Step 71: Receive a shutdown instruction for the mixing drum.

[0135] Step 72: Record the pre-stop speed of the mixing drum and the pre-stop torque of the motor immediately before the stop.

[0136] Step 73: Determine the target pre-torque of the motor based on the pre-stop speed of the mixing drum and the pre-stop torque of the motor.

[0137] In an embodiment of the present application, the candidate pre-torque of the motor is determined based on the pre-stop speed of the mixing drum just before stopping, the actual mass of concrete in the mixing drum, the maximum cross-sectional radius of the mixing drum, and the speed ratio of the reducer, and the maximum value of the candidate pre-torque and the pre-stop torque of the motor corresponding to the mixing drum just before stopping is selected as the target pre-torque of the motor.

[0138] Step 74: Control the motor speed to 0 through the motor speed control mode.

[0139] Step 75: After the motor speed reaches 0, the motor control mode is switched from speed control to torque control.

[0140] Step 76: Determine whether the reverse speed of the motor is greater than the reverse speed threshold, if so, execute step 77, otherwise, execute step 711.

[0141] Step 77: Taking the target pre-torque as the positive torque of the given motor, the motor is made to rotate with the positive torque.

[0142] Step 78: Determine whether the reverse speed of the motor continues to increase. If so, execute step 79; otherwise, execute step 710.

[0143] Step 79: The forward torque of the given motor continues to increase.

[0144] Among them, the increased positive torque is less than or equal to the motor external characteristics.

[0145] Step 710: Determine whether the reverse speed of the motor continues to decrease, if so, execute step 711.

[0146] Step 711: The forward torque of the given motor continues to decrease, and when the distance between the reverse rotation speed and the zero rotation speed is less than a distance threshold, the forward torque is set to 0.

[0147] Based on the same inventive concept, the present application embodiment provides a mixing drum control device, please refer to Figure 8 , the device comprises:

[0148] The determination module 801 is used to receive a stop instruction for the mixing drum, determine the candidate pre-torque of the motor based on the pre-stop speed of the mixing drum immediately before the stop, the actual mass of concrete in the mixing drum, the maximum cross-sectional radius of the mixing drum, and the speed ratio of the reducer, and select the maximum value of the candidate pre-torque and the pre-stop torque of the motor corresponding to the mixing drum immediately before the stop as the target pre-torque of the motor;

[0149] A switching module 802 is used to switch the control mode of the motor from speed control to torque control after the speed of the motor is controlled to 0;

[0150] Processing module 803 is used to control the motor to rotate in the forward direction when the mixing drum is detected to rotate in the reverse direction, wherein the forward rotation control is performed in the following manner: if the reverse speed of the motor is greater than the reverse speed threshold, the target pre-torque is used as the forward torque of the motor, and the forward torque is sent to the motor controller so that the motor controller controls the motor to rotate with the forward torque.

[0151] In a possible embodiment, when determining the target pre-torque of the motor based on the pre-stop speed of the mixing drum immediately before the stop and the pre-stop torque of the motor corresponding to the mixing drum, the determination module 801 is further used to:

[0152] Determine a candidate pre-torque of the motor based on the pre-stop speed of the mixing drum, the actual mass of concrete in the mixing drum, the maximum cross-sectional radius of the mixing drum, and the speed ratio of the reducer;

[0153] The maximum value between the candidate pre-torque and the torque before shutdown is selected as the target pre-torque.

[0154] In a possible embodiment, after the target pre-torque is used as the positive torque of the motor and the positive torque is sent to the motor controller so that the motor controller controls the motor to rotate with the positive torque, the processing module 803 is further used to:

[0155] If the reverse speed of the motor continues to increase, the forward torque continues to increase, wherein the increased forward torque is less than or equal to the motor external characteristic;

[0156] If the reverse speed of the motor continues to decrease, the forward torque continues to decrease, and when the distance between the reverse speed and the 0 speed is less than the distance threshold, the forward torque is set to 0.

[0157] In one possible embodiment, the forward torque is determined based on a torque distribution table, a reverse speed of the motor, a speed of the mixing drum before shutdown, and an actual mass of concrete in the mixing drum;

[0158] The torque distribution table is used to store the motor distribution torques corresponding to each current speed of the motor and each speed before shutdown when the maximum load of concrete is loaded in the mixing drum.

[0159] In a possible embodiment, when it is detected that the mixing drum rotates in the reverse direction, after the motor is controlled to rotate in the forward direction, the processing module 803 is further used to:

[0160] When the forward rotation of the mixing drum is detected, the motor is controlled to rotate in the reverse direction, wherein the reverse rotation control is performed in the following manner: if the forward speed of the motor is greater than the forward speed threshold, the target pre-torque is used as the reverse torque of the motor, and the reverse torque is sent to the motor controller so that the motor controller controls the motor to rotate with the reverse torque.

[0161] In a possible embodiment, after the target pre-torque is used as the reverse torque of the motor and the reverse torque is sent to the motor controller so that the motor controller controls the motor to rotate with the reverse torque, the processing module 803 is further used to:

[0162] If the forward speed of the motor continues to increase, the reverse torque continues to increase, wherein the increased reverse torque is less than or equal to the motor external characteristic;

[0163] If the forward speed of the motor continues to decrease, the reverse torque continues to decrease, and when the distance between the forward speed and the 0 speed is less than the distance threshold, the reverse torque is set to 0.

[0164] Based on the above embodiments, see Fig. 9 Shown is a schematic diagram of the structure of an electronic device in an embodiment of the present application.

[0165] An embodiment of the present application provides an electronic device, which may include a processor 910 (Center Processing Unit, CPU), a memory 920, an input device 930 and an output device 940, etc. The input device 930 may include a keyboard, a mouse, a touch screen, etc., and the output device 940 may include a display device, such as a liquid crystal display (Liquid Crystal Display, LCD), a cathode ray tube (Cathode Ray Tube, CRT), etc.

[0166] The memory 920 may include a read-only memory (ROM) and a random access memory (RAM), and provides the processor 910 with program instructions and data stored in the memory 920. In the embodiment of the present application, the memory 920 may be used to store the program of any mixing drum control method in the embodiment of the present application.

[0167] The processor 910 calls the program instructions stored in the memory 920, and the processor 910 is used to execute any one of the mixing drum control methods in the embodiments of the present application according to the obtained program instructions.

[0168] Based on the above embodiments, in an embodiment of the present application, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the mixing drum control method in any of the above method embodiments is implemented.

[0169] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present application may adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes.

[0170] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the present application. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0171] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0172] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0173] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

Claims

1. A mixing drum control method, characterized in that: include: receiving a stop instruction for a mixing drum, determining a candidate pre-torque of a motor corresponding to the mixing drum based on a pre-stop speed of the mixing drum immediately before the stop, an actual mass of concrete in the mixing drum, a maximum cross-sectional radius of the mixing drum, and a speed ratio of a reducer, and selecting a maximum value between the candidate pre-torque and the pre-stop torque of the motor immediately before the stop as a target pre-torque of the motor; After controlling the speed of the motor to be 0, switching the control mode of the motor from speed control to torque control; When it is detected that the mixing drum is rotating in the opposite direction, the motor is controlled to rotate in the forward direction, wherein the forward rotation control is performed in the following manner: if the reverse speed of the motor is greater than a reverse speed threshold, the target pre-torque is used as the forward torque of the motor, and the forward torque is sent to the motor controller so that the motor controller controls the motor to rotate with the forward torque.

2. The method according to claim 1, characterized in that After taking the target pre-torque as the positive torque of the motor and sending the positive torque to the motor controller so that the motor controller controls the motor to rotate with the positive torque, the method further includes: If the reverse speed of the motor continues to increase, the forward torque is continuously increased, wherein the increased forward torque is less than or equal to the motor external characteristic; If the reverse rotation speed of the motor continues to decrease, the forward torque is continuously reduced, and when the distance between the reverse rotation speed and the zero rotation speed is less than a distance threshold, the forward torque is set to 0.

3. The method according to claim 2, characterized in that The forward torque is determined based on a torque distribution table, a reverse speed of the motor, a speed of the mixing drum before shutdown, and an actual mass of concrete in the mixing drum; The torque distribution table is used to store the motor distribution torques corresponding to each current rotation speed of the motor and each rotation speed before shutdown when the maximum load of concrete is loaded in the mixing drum.

4. The method according to claim 1, characterized in that After the motor is controlled to rotate in the forward direction when the mixing drum is detected to rotate in the reverse direction, the method further comprises: When it is detected that the mixing drum is rotating in the forward direction, the motor is controlled to rotate in the reverse direction, wherein the reverse rotation control is performed in the following manner: if the forward speed of the motor is greater than the forward speed threshold, the target pre-torque is used as the reverse torque of the motor, and the reverse torque is sent to the motor controller so that the motor controller controls the motor to rotate with the reverse torque.

5. The method according to claim 4, characterized in that After taking the target pre-torque as the reverse torque of the motor and sending the reverse torque to the motor controller so that the motor controller controls the motor to rotate with the reverse torque, the method further includes: If the forward speed of the motor continues to increase, the reverse torque continues to increase, wherein the increased reverse torque is less than or equal to the motor external characteristic; If the forward speed of the motor continues to decrease, the reverse torque continues to decrease, and when the distance between the forward speed and the 0 speed is less than a distance threshold, the reverse torque is set to 0.

6. A mixing drum control device, characterized in that: include: a determination module, configured to receive a stop instruction for a mixing drum, determine a candidate pre-torque of a motor corresponding to the mixing drum based on a pre-stop speed of the mixing drum immediately before the stop, an actual mass of concrete in the mixing drum, a maximum cross-sectional radius of the mixing drum, and a speed ratio of a reducer, and select a maximum value between the candidate pre-torque and the pre-stop torque of the motor immediately before the stop as a target pre-torque of the motor; A switching module, used for switching the control mode of the motor from speed control to torque control after the speed of the motor is controlled to be 0; A processing module is used to control the motor to rotate in the forward direction when the mixing drum is detected to rotate in the reverse direction, wherein the forward rotation control is performed in the following manner: if the reverse speed of the motor is greater than a reverse speed threshold, the target pre-torque is used as the forward torque of the motor, and the forward torque is sent to the motor controller so that the motor controller controls the motor to rotate with the forward torque.

7. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the program, the steps of the method according to any one of claims 1 to 5 are implemented.

8. A new energy vehicle, characterized in that: Comprising the device as claimed in claim 6.

9. An electric mixer truck, characterized in that: The electric mixer truck comprises a vehicle body and a mixing drum, and the electric mixer truck also comprises a mixing drum control device as described in claim 6.

Images