A road strength meter control system and its control method

Abstract

The present invention discloses a road strength tester control system and its control method, which includes a first actuator, a second actuator and a control mechanism; the first actuator includes a main controller, a servo motor, a servo motor driver, a first speed reduction unit and a first connector, the second actuator includes a strong electricity controller, a three-phase motor, a second speed reduction unit and a second connector, and the control mechanism includes a force sensor, a displacement sensor, a power supply and a control host; the present invention adds a set of servo drive system to the original system, adopts two sets of drive systems to drive independently at different times, especially adopts servo force closed-loop control during the loading, holding and unloading processes, truly realizes the controllability and high control accuracy of the force loading process, and further improves the technical level of the product.

Description

Technical Field

[0001] The invention belongs to the technical field of road strength meter control, and particularly relates to a road strength meter control system and a control method thereof. Background Art

[0002] A pavement material strength comprehensive tester supports the operation and control of tests such as Marshall test, California Bearing Ratio (CBR) test, unconfined compressive strength test, etc., and is a special device for realizing the pavement material strength determination test regulations.

[0003] The control system of the traditional road strength meter uses a strong electric control board to control a common three-phase motor to rotate at a constant speed and switch the rotation direction to realize the uniform displacement control and the up / down function of the cross beam. The displacement rates involved in the moving cross beam and the loading process vary greatly. Usually, the moving speed of the cross beam is relatively fast, reaching 50 mm / min, and the moving rate during the loading process is very slow after pressing on the test block. Usually, the set value is 1 - 2 mm / min. The technical means adopted is to replace two sets of reduction mechanisms with different speed ratios to realize the control of the fixed displacement.

[0004] Obviously, the disadvantages of the above traditional technical solutions are as follows: (1) The displacement rate control of the target loading specimen is realized through the cooperation of the motor constant speed control and the reduction mechanism. This control is open-loop and cannot realize the force closed-loop control of the specimen. Therefore, the force control during the specimen loading process cannot be truly and effectively controlled, and only the open-loop control of the displacement rate is used to approximately achieve the effect of partial force control; (2) When it is necessary to switch different displacement control rates, another set of reduction mechanisms needs to be replaced, and the on-site test process is relatively cumbersome and the degree of automation is low; (3) Only a digital display module is connected and it does not support networking docking and data uploading. The above traditional conventional solution is the current main control system solution, and the industry has also carried out technological innovations for the disadvantage of needing to replace the reduction mechanism during its test process. For example, some manufacturers have achieved the function of not needing to replace the reduction mechanism by adding a set of common three-phase motors and corresponding reduction mechanisms, thereby improving the test efficiency accordingly. Summary of the Invention

[0005] The invention overcomes the deficiencies of the prior art and provides a road strength meter control system and a control method thereof to solve the problems existing in the prior art.

[0006] To achieve the above object, the technical solution adopted by the invention is: a road strength meter control system, including a first actuator, a second actuator and a control mechanism; wherein:

[0007] The first actuator includes a main controller, a servo motor, a servo motor driver, a first speed reduction unit, and a first connector. The second actuator includes a strong power controller, a three-phase motor, a second speed reduction unit, and a second connector. The control mechanism includes a force sensor, a displacement sensor, a power supply, and a control host;

[0008] The main controller is connected to the force sensor, the displacement sensor, the power supply, the servo motor driver, the strong power controller, and the control host. The main controller is communicatively connected to the control host through an Ethernet port or a serial port. The main controller can perform synchronous measurement and control of force and displacement, and can drive and control the servo motor. By driving and controlling the servo motor, the main controller performs loading, holding, and unloading of the force closed-loop control or displacement closed-loop control of the system;

[0009] The strong power controller is connected to the power supply, the three-phase motor, and the main controller. The strong power controller receives the control instruction from the main controller and controls the rotation speed of the three-phase motor by controlling the on / off of the relay to achieve the open-loop displacement control of the system;

[0010] The control host is equipped with upper computer control software, and the control host performs data and control interaction with the main controller through an Ethernet port or a serial port.

[0011] Both the main controller and the strong power controller are equipped with embedded software.

[0012] Preferably, the control host is an industrial control screen or a control computer, and the upper computer control software in the control host can upload the acquired experimental data to the server through the network.

[0013] The present invention also discloses a control method for a road strength tester control system, including the following steps:

[0014] S1. Initialization: The system powers on and performs self-check. The embedded software of the main controller and the upper computer control software both perform initialization operations according to the predetermined design. After the upper computer software connects to the main controller, it reads the parameters saved inside the main controller and checks and validates them against the parameters saved by the upper computer software;

[0015] S2. Open-loop operation: Lift the crossbeam. The upper computer software sends instructions to the main controller according to the predetermined design, and the main controller sends instructions to the strong power controller to complete the combination with the second connector and start the three-phase motor to run at a fixed speed;

[0016] S3. Loading and entering. When the oil cylinder piston contacts the sample to be measured and the loading force reaches the inlet force, it automatically switches to the closed-loop loading state. At this time, the host computer software sends an instruction to the main controller, and the main controller sequentially completes the actions of stopping the three-phase motor, separating the second connector, and engaging the first connector through controlling the power controller. Then, the main controller drives the servo motor for closed-loop force control;

[0017] S4. Uniform loading or unloading. The main controller performs closed-loop PID control on the required force rate and the actual force rate. When the force value reaches the holding target preset by the host computer software, it enters the holding stage, and the main controller performs closed-loop PID control on the required force value and the actual force value;

[0018] S5. End control. The host computer software sends an instruction to the main controller according to the predetermined design. The main controller and the power controller sequentially complete the actions of stopping the servo motor, separating the first connector, and engaging the second connector. Then, the main controller drives the three-phase motor to retract the crossbeam through the power controller.

[0019] S6. The embedded software of the main controller starts the Ethernet or serial communication data upload every fixed time period Tp, sends the data of the full-channel force and displacement that have been saved according to the operation rules, and the host computer software of the control host receives the data sent from the main controller in real time. The host computer software supports the import of various different experimental projects, the generation of reports, the control of the test process, and the upload management of test data.

[0020] Preferably, the processing algorithm steps of the embedded software of the main controller are as follows:

[0021] T1. Real-time collect the values of the force sensor and the displacement sensor, and perform filtering algorithm processing on the original code values of the force sensors of each channel collected, without performing filtering processing on the displacement sensor values;

[0022] T2. According to the operation instructions from the host computer, operate and control the three-phase motor and the servo motor respectively. Specifically: for fast movement operations such as moving the crossbeam, send control instructions from the main controller to the power controller, engage the connector corresponding to the three-phase motor, and then operate the three-phase motor through the power controller to achieve constant speed control to reach the required moving speed. The running direction of the three-phase motor is set by the power controller. For slower speed control operations such as loading, holding, and unloading, directly control and drive the servo motor through the main controller to achieve closed-loop force control. At this time, it is required to disconnect the second connector corresponding to the three-phase motor and close the first connector corresponding to the servo motor;

[0023] T3. The main controller sends the experimental data collected in real time from each channel to the host computer for result display and process control. The host computer software is responsible for overall planning of the actions of each actuator, diagnostic processing, and safety protection processing.

[0024] Preferably, in step S6, the time period Tp can optionally be set to 20 ms; the operation rule is: header + check code + system status + abnormal status + force channel value + displacement channel 0 value + displacement channel 1 value.

[0025] The present invention solves the defects existing in the background technology and has the following beneficial effects:

[0026] (1) The present invention adds a set of servo drive systems to the original system and adopts two sets of drive systems to drive independently at different times. Especially in the loading, holding, and unloading processes, servo force closed-loop control is adopted, truly realizing the controllability and high control accuracy of the force loading process, and further improving the technical level of the product.

[0027] (2) Through two sets of actuators, the servo motor + speed reducer unit and connector, and the three-phase motor + speed reducer unit and connector, full-automatic control of the test process is realized, and the test efficiency is greatly improved.

[0028] (3) It can support connection to an industrial control screen or a computer, support network connection and test data upload, meeting the requirements of the national quality inspection department for the supervision of the construction quality of engineering materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, for those of ordinary skill in the art, other drawings can also be obtained based on these drawings without creative efforts.

[0030] Figure 1 It is a connection schematic diagram of a preferred embodiment of the present invention;

[0031] Figure 2 It is a module schematic diagram of the control system of a preferred embodiment of the present invention;

[0032] Figure 3 It is a flowchart of the control system of a preferred embodiment of the present invention;

[0033] In the figure: 1, control host; 2, servo motor driver; 3, main controller; 4, displacement sensor; 5, servo motor; 6, three-phase motor; 7, force sensor; 8, strong electricity controller; 9, speed reducer unit. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0034] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention.

[0035] Combined with Figure 1 And Figure 2 As shown, a road strength meter control system includes a first actuator, a second actuator and a control mechanism; wherein:

[0036] The first actuator includes a main controller 3, a servo motor 5, a servo motor driver 2, a first reduction gear set and a first connector. The second actuator includes a strong electricity controller 8, a three-phase motor 6, a second reduction gear set and a second connector. The control mechanism includes a force sensor 7, a displacement sensor 4, a power supply and a control host 1. Both the first reduction gear set and the second reduction gear set belong to the reduction gear set 9.

[0037] The main controller 3 is connected to the force sensor 7, the displacement sensor 4, the power supply, the servo motor driver 2, the strong electricity controller 8 and the control host 1. The main controller 3 communicates with the control host 1 through an Ethernet port or a serial port. The main controller 3 can synchronously measure and control the force and displacement, and the main controller 3 can drive and control the servo motor 5. By driving and controlling the servo motor 5, the main controller 3 performs loading, holding and unloading on the force closed-loop control or displacement closed-loop control of the system;

[0038] The strong electricity controller 8 is connected to the power supply, the three-phase motor 6 and the main controller 3. The strong electricity controller 8 receives the control instructions from the main controller 3 and controls the rotation speed of the three-phase motor 6 by controlling the on-off of the relay to achieve the displacement open-loop control of the system;

[0039] The control host 1 is equipped with upper computer control software, and the control host 1 conducts data and control interaction with the main controller 3 through an Ethernet port or a serial port.

[0040] Both the main controller 3 and the strong electricity controller 8 are equipped with embedded software.

[0041] Specifically, the control host 1 is an industrial control screen or a control computer, and the upper computer control software in the control host 1 can upload the obtained experimental data to the server through the network.

[0042] Such as Figure 2 As shown, a control method for a road strength meter control system includes the following steps:

[0043] S1. Initialization: When the system powers on for self-check, the embedded software of the main controller 3 and the host computer control software are both initialized according to the predetermined design. After the host computer software connects to the main controller 3, it reads the parameters saved inside the main controller 3 and checks and verifies them against the parameters saved in the host computer software.

[0044] S2. Open-loop operation: Lift the crossbeam. The host computer software sends instructions to the main controller 3 according to the predetermined design. The main controller 3 then sends instructions to the power controller 8 to complete the combination with the second connector and start the three-phase motor 6 to run at a fixed speed.

[0045] S3. Loading entry: When the oil cylinder piston contacts the sample to be measured and the loading force reaches the inlet force, it automatically switches to the closed-loop loading state. At this time, the host computer software sends instructions to the main controller 3. The main controller 3 sequentially completes the actions of stopping the three-phase motor 6, separating the second connector, and combining the first connector through controlling the power controller 8. Then, the main controller 3 drives the servo motor 5 for closed-loop force control.

[0046] S4. Uniform loading or unloading: The main controller 3 performs closed-loop PID control on the required force rate and the actual force rate. When the force value reaches the holding target preset by the host computer software, it enters the holding stage, and the main controller 3 performs closed-loop PID control on the required force value and the actual force value.

[0047] S5. End control: The host computer software sends instructions to the main controller 3 according to the predetermined design. The main controller 3 and the power controller 8 sequentially complete the actions of stopping the servo motor 5 from running, separating the first connector, and combining the second connector. Then, the crossbeam is retracted by driving the three-phase motor 6 through the power controller 8.

[0048] S6. The embedded software of the main controller 3 starts the Ethernet or serial communication data upload every fixed time period Tp, and sends the saved data of all-channel force and displacement according to the operation rules. The host computer software of the control host 1 receives the data sent from the main controller 3 in real time. The host computer software supports the import of various different experimental projects, the generation of reports, the control of the test process, and the upload management of test data.

[0049] In this embodiment, the processing algorithm steps of the embedded software of the main controller 3 are as follows:

[0050] T1. Real-time collect the values of the force sensor 7 and the displacement sensor 4, and perform filtering algorithm processing on the original code values of each channel force sensor 7 collected, without performing filtering processing on the values of the displacement sensor 4.

[0051] T2. According to the operation instructions from the host computer, the three-phase motor 6 and the servo motor 5 are respectively operated and controlled. Specifically: for rapid movement operations such as the moving crossbeam, the main controller 3 sends control instructions to the power controller 8, combined with the connector corresponding to the three-phase motor 6, and then the power controller 8 operates the three-phase motor 6 to achieve constant-speed control to reach the required moving speed. The running direction setting of the three-phase motor 6 is controlled by the power controller 8; for slower-speed control operations such as loading, holding, and unloading, the main controller 3 directly controls and drives the servo motor 5 to achieve closed-loop force control. At this time, it is required to disconnect the second connector corresponding to the three-phase motor 6 and close the first connector corresponding to the servo motor 5.

[0052] T3. The main controller 3 sends the experimental data collected in real time from each channel to the host computer for result display and process control processing. The host computer software is responsible for overall planning of the actions of each actuator, diagnostic processing, and safety protection processing.

[0053] Specifically, in step S6, the time period Tp can be optionally set to 20 ms; the operation rule is: header + check code + system status + abnormal status + force channel value + displacement channel 0 value + displacement channel 1 value.

[0054] In the description of this specification, the descriptions referring to terms such as "one embodiment", "example", "specific example", etc. mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0055] The above shows and describes the basic principles, main features, and advantages of the present invention. Those skilled in the art of this industry should understand that the present invention is not limited by the above embodiments. The above embodiments and the descriptions in the specification only illustrate the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed.

Claims

1. A road strength meter control system, characterized in that, It includes a first actuator, a second actuator and a control mechanism; where: The first actuator includes a main controller, a servo motor, a servo motor driver, a first reduction gear set and a first connector. The second actuator includes a strong electricity controller, a three-phase motor, a second reduction gear set and a second connector. The control mechanism includes a force sensor, a displacement sensor, a power supply and a control host; The main controller is connected to the force sensor, the displacement sensor, the power supply, the servo motor driver, the strong electricity controller and the control host; The strong electricity controller is connected to the power supply, the three-phase motor and the main controller. The strong electricity controller receives the control instruction from the main controller and controls the rotation speed of the three-phase motor by controlling the on / off of the relay to achieve the open-loop displacement control of the system; According to the operation instructions from the upper computer, the three-phase motor and the servo motor are respectively operated and controlled. For the fast movement operation of the moving crossbeam, the main controller sends a control instruction to the strong electricity controller, combines with the corresponding connector of the three-phase motor, and then the strong electricity controller operates the three-phase motor to achieve constant speed control to reach the required moving speed. The running direction of the three-phase motor is set and controlled by the strong electricity controller. For the slower speed control operations of loading, holding load and unloading, the main controller directly controls and drives the servo motor to achieve closed-loop force control. At this time, it is required to disconnect the second connector corresponding to the three-phase motor and connect the first connector corresponding to the servo motor.

2. The road strength meter control system according to claim 1, characterized in that The control host is an industrial control screen or a control computer. The upper computer control software in the control host can upload the acquired experimental data to the server through the network.

3. A control method for a road strength meter control system, applied to a road strength meter control system according to any one of claims 1-2, characterized in that, It includes the following steps: S1. Initialization: The system powers on and performs self-check. The embedded software of the main controller and the upper computer control software are both initialized according to the predetermined design. After the upper computer software connects to the main controller, it reads the parameters saved inside the main controller and checks and verifies them with the parameters saved by the upper computer software. After the system self-check and verification are passed, the upper computer software and the embedded software will be in the READY state waiting for system instructions; S2. Open-loop operation: Lift the crossbeam. The upper computer software sends an instruction to the main controller according to the predetermined design. The main controller sends an instruction to the strong electricity controller to complete combining the second connector and starting the three-phase motor to run at a fixed speed; S3. Loading entry: When the oil cylinder piston contacts the sample to be tested and the loading force reaches the inlet force, it automatically switches to the closed-loop loading state. At this time, the upper computer software sends an instruction to the main controller. The main controller sequentially completes the actions of stopping the three-phase motor, separating the second connector and combining the first connector by controlling the strong electricity controller, and then the main controller drives the servo motor for closed-loop force control; S4. Uniform loading or unloading: The main controller performs closed-loop PID control on the required force rate and the actual force rate; when the force value reaches the holding target preset by the upper computer software, it enters the holding stage, and the main controller performs closed-loop PID control on the required force value and the actual force value; S5. End control: The host computer software sends instructions to the main controller according to the predetermined design. The main controller and the high-voltage controller sequentially complete the actions of stopping the servo motor, separating the first connector, and connecting the second connector, and then drive the three-phase motor to retract the crossbeam through the high-voltage controller. S6. The embedded software of the main controller starts the upload of Ethernet or serial communication data every fixed time period Tp, and sends the saved data of the full-channel force and displacement according to the operation rules; the host computer software of the control host receives the data sent from the main controller in real time. The host computer software supports the import of various different experimental projects, the generation of reports, the control of the test process, and the upload management of test data.

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