Wood chip unloading screw position monitoring system

Abstract

The utility model discloses wood chip unloading spiral position monitoring system passes through gear pulse counting and combines the dynamic calibration of limit switch, realizes high accuracy, low -cost displacement detection. System sets limit switch in track starting point, terminal point and intermediate point, utilizes controller real -time correction gear counting error, has effectively solved the problem that traditional encoder is bad to anti -interference, and cumulative error is big. Besides, system supports wireless communication extension, is applicable to wood chip conveying etc. industrial scene.

Description

Technical Field

[0001] This utility model belongs to the technical field of material conveying equipment, and relates to a discharge screw position monitoring system for a wood chip conveying system, which is suitable for automated conveying scenarios of loose materials such as wood chips and biomass pellets. Background Technology

[0002] Existing unloading auger position detection systems mainly rely on rotary encoders or laser rangefinders, which have the following drawbacks: 1) High cost: High-precision encoders are expensive and require regular calibration and maintenance; 2) Poor anti-interference ability: Encoders are susceptible to mechanical vibration, dust pollution and humidity, which can lead to signal distortion or loss; 3) Large cumulative error: During long-term operation, due to gear slippage, wear or temperature changes, position detection deviations gradually accumulate, affecting positioning accuracy.

[0003] Existing gear counting systems, such as those using 6-tooth gears and two pulse sensors XS1 and XS2, have a simple structure, but they are prone to counting errors due to signal delay or jitter when switching between forward and reverse directions. Furthermore, they lack real-time calibration functions, making it difficult to meet high reliability requirements. Utility Model Content

[0004] This utility model aims to provide a wood chip unloading auger position monitoring system. By optimizing the coordinated operation of gear counting and limit switches, it achieves high-precision and low-cost displacement detection and solves the problems of large cumulative error and poor anti-interference ability in the prior art. The system has the characteristics of dynamic calibration, redundancy verification and strong scalability.

[0005] The technical solution of this utility model: A wood chip unloading auger position monitoring system, characterized in that it includes: A gear-rack transmission unit, comprising meshing gears and a rack, is used to convert the rotational motion of the unloading auger into linear displacement; A pulse sensor is used to detect the number of teeth rotating in a gear and generate a pulse signal. Limit switch assembly, with multiple limit switches arranged along the track; The controller is configured to calculate the real-time displacement based on pulse signals and correct the calculated displacement value to eliminate accumulated errors when the limit switch is triggered; The gear-rack transmission unit meshes to drive the unloading screw travel mechanism to move; the pulse sensor is installed on the side of the gear to detect changes in tooth profile; the limit switch includes at least a start limit switch and an end limit switch; the controller connects all sensors and limit switches via cables, and the pulse signal line and limit switch signal line are connected to the controller input port, with the controller outputting control signals to the motor driver; the number of pulse sensors is two, and the pulse sensors are installed with a preset phase difference; the limit switch group includes three or more limit switches arranged at the start and end points of the travel track and at least one intermediate calibration point.

[0006] The innovative aspects of this utility model and its beneficial effects are as follows: (1) Dynamic segmented calibration mechanism: The system sets forced calibration points at the start, end and intermediate positions, and automatically compares the theoretical displacement with the actual pulse count value by triggering limit switches to correct the counter error in real time. For example, at the intermediate limit point, the theoretical number of teeth (e.g., 300 teeth) is compared with the actual number of detected teeth (e.g., 288 teeth), and the displacement of a single tooth is dynamically adjusted to effectively suppress the cumulative error.

[0007] (2) Redundancy and fault tolerance design and reliability improvement: The dual verification strategy of gear counting and limit switch is adopted to form a redundant signal path, which enhances the fault tolerance and operational reliability of the system under complex working conditions.

[0008] (3) Anti-interference signal processing optimization: Combine hardware filtering (such as RC circuit) and software algorithm (such as digital filtering) to denoise the pulse signal, which significantly reduces false triggering and counting deviation caused by electromagnetic interference or mechanical vibration.

[0009] (4) Low-cost and highly scalable architecture: Based on a general-purpose pulse sensor and a standard controller, it replaces the traditional high-precision encoder, significantly reducing costs while ensuring accuracy. The system supports integrated wireless communication modules, facilitating remote status monitoring and fault diagnosis, and has good functional scalability. Attached Figure Description

[0010] Figure 1 This is a schematic diagram of the system structure.

[0011] Figure 2 This is a control logic flowchart.

[0012] Figure 3 This is a flowchart of the error compensation algorithm.

[0013] Figure 4 This is an extended functional block diagram for Example 2.

[0014] In the diagram: 1-Gear; 2-Rack; 3-Unloading screw travel mechanism; 4-Pulse sensor XS1; 5-Pulse sensor XS2; 6-Limit switch S1; 7-Limit switch S2; 8-Limit switch S3; 9-Controller; 10-Wireless communication module; 11-Database; 12-Cloud server; 13-User interface. Detailed Implementation

[0015] The following describes two preferred embodiments of the present invention in detail with reference to the accompanying drawings.

[0016] Example 1: Basic Implementation Figure 1 As shown: Wood chip unloading auger position monitoring system.

[0017] Mechanical transmission section: A gear-rack transmission unit consisting of gear 1 and rack 2 is used to convert the rotational motion of the gears into the linear displacement of the unloading screw traveling mechanism 3. The parameters of gear 1 are: module 2, number of teeth 6, pitch circle diameter 12mm, and circumference 37.7mm. Therefore, the traveling mechanism is displaced by 37.7mm for each rotation of the gear.

[0018] The sensing section includes two pulse sensors, XS1 4 and XS2 5, mounted on the side of gear 1. These sensors detect the number of teeth rotating and generate phase difference pulse signals. Gear 1 is designed with 6 teeth; the count increases or decreases by 1 whenever two teeth's signals are detected, thus improving resolution and anti-interference capability. The limit switch assembly includes a start limit switch S1 6, an end limit switch S2 7, and an intermediate limit switch S3 8, arranged along the track at approximately 1-meter intervals to provide an absolute position reference. Additionally, the system can be configured with left and right emergency limit switches to handle abnormal situations.

[0019] Control Core: Controller 9 connects to all sensors and limit switches via cables. It receives pulse signals and limit switch signals and outputs control signals to the motor driver. The controller supports counting direction switching U / DN signals, where "1" indicates forward counting and "0" indicates reverse counting.

[0020] Figure 2 The following are the steps for using the wood chip unloading auger position monitoring system: 1) The rotation pulses of the gear driving the unloading screw are detected by pulse sensors. After the system starts, the unloading screw traveling mechanism 3 resets to the starting point, triggering the starting point limit switch S1 6, and the controller 9 clears the internal counter. During the travel, pulse sensors XS1 4 and XS2 5 detect changes in the gear tooth profile and generate pulse signals. The controller 9 determines the direction of movement by the level of the U / DN signal ("1" for forward counting, "0" for reverse counting).

[0021] 2) Calculate the real-time displacement of the unloading screw based on pulse accumulation. Controller 9 accumulates pulse signals and calculates the real-time displacement based on the gear circumference (37.7 mm / revolution) and pulse count (one pulse count for every two teeth). For example, one revolution of the gear corresponds to 6 teeth, generating 3 counts, resulting in a displacement of 37.7 mm.

[0022] 3) When a limit switch set on the walking track is triggered, the dynamic calibration process is started. When the walking mechanism triggers any limit switch (such as the start point S1, the middle point S3, or the end point S2), the controller 9 immediately interrupts the normal process and starts the dynamic calibration subprocess.

[0023] 4) In the dynamic calibration process, the displacement calculation parameters are corrected based on the known position information of the triggered limit switch to eliminate cumulative errors.

[0024] The specific calibration sub-process is attached. Figure 3 As shown: (1) Controller 9 reads the current actual count value (N_actual).

[0025] (2) Obtain the theoretical count value (N_theoretical) for this segment of travel. For example, the distance from the starting point to the intermediate limit switch S3 is 30 meters, and the theoretical number of teeth is 300 (based on gear parameters and pulse counting rules).

[0026] (3) Calculate the correction factor K: K = N_theoretical / N_actual.

[0027] (4) Update the conversion relationship between pulse and displacement using K: the displacement corresponding to a single tooth is S_new = S_old × K. For example, if the theoretical displacement of 30 meters corresponds to 300 teeth, but 288 teeth are actually detected, then K = 300 / 288 ≈ 1.0417, and the new single-tooth displacement is corrected by multiplying the original value by K. Apply the new parameters, and use the corrected conversion relationship for subsequent displacement calculations until the next calibration.

[0028] When the end limit switch S2 is reached, the walking mechanism stops, and the controller 9 records the final position and updates the system.

[0029] Example 2: Extended Implementation Wood chip unloading auger position monitoring system. Based on Example 1, this example further adds remote monitoring functionality. The system architecture is shown in the attached figure. Figure 4 As shown. In the local system, controller 9 adds a connection to wireless communication module 10 (such as a Wi-Fi module).

[0030] The controller 9 transmits real-time location, calibration records, equipment status and alarm information to the cloud server 11 via the wireless communication module 10.

[0031] The cloud server 11 stores the data in the database 12 and can display it to the user through the user interface 13 (such as a PC or mobile app), enabling remote monitoring, historical data query and predictive maintenance.

Claims

1. A wood chip unloading auger position monitoring system, characterized in that, include: A gear-rack transmission unit, comprising meshing gears and a rack, is used to convert the rotational motion of the unloading auger into linear displacement; A pulse sensor is used to detect the number of teeth rotating in a gear and generate a pulse signal. Limit switch assembly, with multiple limit switches arranged along the track; The controller is configured to calculate the real-time displacement based on pulse signals and correct the calculated displacement value to eliminate accumulated errors when the limit switch is triggered; The gear-rack transmission unit meshes to drive the unloading screw travel mechanism to move; the pulse sensor is installed on the side of the gear to detect changes in tooth profile; the limit switch includes at least a start limit switch and an end limit switch; the controller connects all sensors and limit switches via cables, and the pulse signal line and limit switch signal line are connected to the controller input port, with the controller outputting control signals to the motor driver; the number of pulse sensors is two, and the pulse sensors are installed with a preset phase difference; the limit switch group includes three or more limit switches arranged at the start and end points of the travel track and at least one intermediate calibration point.

Images