On-line test calibration device for vehicle gear shifting control mechanism
By using a six-axis robotic arm and a U-shaped test arm in conjunction with an online testing and calibration device with multiple sensors, the problem of low testing and calibration efficiency of vehicle gear shifting mechanisms has been solved, achieving efficient and accurate automated testing and calibration.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SHENZHEN DIERTAI TECH CO LTD
- Filing Date
- 2026-02-25
- Publication Date
- 2026-04-17
AI Technical Summary
In the existing technology, the testing and calibration methods for vehicle gear shifting mechanisms are inefficient and prone to errors, and cannot achieve efficient and accurate automated testing.
An online testing and calibration device consisting of a six-axis robotic arm, a U-shaped test arm, multiple sensors, and controllers enables automated testing and calibration of the gear shifting mechanism through the handling of the robotic arm, the reciprocating motion of the U-shaped test arm, and the cooperation of multiple sensors, while transmitting data using the TCP/IP protocol.
It enables efficient and accurate testing and calibration of the gear shifting mechanism, improves production efficiency and testing quality, reduces manual intervention, has a simple structure, occupies little space, and is inexpensive.
Smart Images
Figure CN121877415A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of vehicle technology, and in particular relates to an online testing and calibration device for a vehicle gear shifting mechanism. Background Technology
[0002] After assembly, the gear shifting system of a car may have manufacturing or assembly defects due to various reasons. These defects must be resolved before the car is assembled. In addition, the mechanical travel or rotation angle and displacement thrust of the gear selector rocker arm to each gear need to be measured after the assembly. If the measurement is qualified, it is calibrated to ensure the normal operation of the gear shifting system. Different vehicles have different test and calibration methods for their gear shifting systems, but most of them use a semi-automatic test and calibration method that combines manual and mechanical methods. This semi-automatic test and calibration method is not only inefficient, but also has test and calibration errors. Summary of the Invention
[0003] The purpose of this invention is to provide an online testing and calibration device for the gear shifting mechanism of vehicles, which can accurately test and calibrate the gear shifting mechanism of HTEB and SZEA products, and improve the efficiency and quality of testing and calibration.
[0004] The objective of this invention is achieved as follows: An online testing and calibration device for a vehicle gear shifting mechanism includes a workbench. A first tray is mounted on an upper conveyor rail on one side of the workbench, and a robotic arm and a testing and calibration fixture are mounted on the other side. The testing and calibration fixture includes a second tray, a fixing component, a power-conducting component, and a testing component capable of horizontal, vertical, and lateral movement. The robotic arm can move the gear shifting mechanism from the first tray to the second tray and vice versa. The testing end of the testing component has a U-shaped testing arm with an opening facing downwards. Force sensors, angle sensors, or displacement sensors are respectively mounted on the inner sides of the two vertical arms of the U-shaped testing arm. The reciprocating movement of the U-shaped testing arm can test the displacement angle, displacement stroke, and displacement thrust of the gear shifting mechanism's gear selector arm between gears D, N, and R. The test data is compared with pre-stored standard values in the controller. If the comparison result meets the requirements, online calibration is performed directly on the Hall effect sensor of the gear shifting mechanism; if the comparison result does not meet the requirements, an alarm is triggered.
[0005] As a further optimization of the above technical solution, the controller adopts the TCP / IP protocol and RJ45 interface to realize the information transmission and storage of data and test parameters collected during the testing of the gear shifting mechanism.
[0006] As a further optimization of the above technical solution, the robotic arm is a six-axis robotic arm. The middle part of the mounting plate is fixed on the rotating shaft at the end of the robotic arm of the six-axis robotic arm. The two ends of the mounting plate are respectively provided with two grippers driven by the first cylinder to move relative to each other to clamp and hold the shift control mechanism. The two grippers are respectively provided with a first sensor to detect the presence of the shift control mechanism. The detection signal of the first sensor is transmitted to the controller. An elastic clamping column is provided on the mounting plate between the two grippers.
[0007] As a further optimization of the above technical solution, the fixing component consists of two lifting and rotating cylinders on a bracket on one side of the second tray. A first horizontal cantilever is fixed to the end of the piston rod extending upward outside the lifting and rotating cylinders. A pressure block is provided on the lower surface of the outer end of the first cantilever. The first cantilever can rotate 90 degrees with the piston rod. The pressure block can be released or pressed against the shifting control mechanism as the first cantilever and the piston rod rise and fall.
[0008] As a further optimization of the above technical solution, the power-on component is a slide plate that is slidably mounted on a transverse slide rail on a bracket on one side of the second tray. A second cantilever that is driven to move up and down is fixed on the bracket of the slide plate. A probe assembly is provided at the lower outer end of the second cantilever that can make electrical contact with the corresponding electrical contacts on the circuit board of the shift control mechanism. The probe assembly is electrically connected to the controller.
[0009] As a further optimization of the above technical solution, the test component includes a first slider driven by a first motor to slide on a horizontal slide rail, a second slider driven by a second motor to slide on a vertical slide rail, and a third slider driven by a third motor to slide on a vertical slide rail, the lower part of the third slider being the test end, and the test end being provided with the U-shaped test arm.
[0010] As a further optimization of the above technical solution, a second sensor is provided on one side of both the first tray and the second tray to detect the presence of the shift control mechanism, and the detection signal of the second sensor is transmitted to the controller.
[0011] As a further optimization of the above technical solution, a barcode scanner is provided on the worktable on one side of the first tray to scan the product QR code on the shift control mechanism, and the scanning signal of the barcode scanner is transmitted to the controller.
[0012] As a further optimization of the above technical solution, a lower conveying rail is provided on the lower side of the workbench, and lifting platforms driven by a fourth cylinder are provided at both ends of the upper and lower conveying rails respectively, so as to transfer the first pallet on the upper conveying rail back to the upper conveying rail via the lower conveying rail, thereby realizing the reuse of the first pallet. Both the upper and lower conveying rails are automatic double-speed chains with adjustable width. A third sensor is provided on the lifting platform to detect whether the shift control mechanism is in position, and the detection signal of the third sensor is transmitted to the controller.
[0013] As a further optimization of the above technical solution, the workbench is provided with a first tray pause position. On the entry side of the pause position, a fourth sensor is provided to sense whether the shift control mechanism has entered, and on the exit side, a fifth sensor is provided to detect whether the shift control mechanism is in position, as well as a blocking block driven by a fifth cylinder for lifting. The blocking block is provided with pneumatic or spring damping components. On the lower side of the pause position, a lifting plate driven by a sixth cylinder is provided. The lifting plate is provided with a positioning pin that matches the positioning hole on the first tray and a sixth sensor to sense whether the first tray has been lifted into position. The detection signals of the fourth, fifth, and sixth sensors are transmitted to the controller.
[0014] The advantages of this invention compared to the prior art are: 1. The six-axis robot of the present invention adopts a two-set double-gripper structure, which can pick up two kinds of products from the first tray and the second tray at the same time. The products picked up from the first tray are placed into the testing and calibration equipment for testing and calibration, and the products picked up from the second tray are placed into the automated double-speed chain and controlled by the controller to be sent into different tracks of the next process according to whether they are qualified or unqualified. This makes the transfer and transportation of the tested and calibrated products simple and fast, with a simple structure and short transportation time.
[0015] 2. This invention uses a 90-degree lifting and rotating cylinder, its first cantilever, and a pressure block to clamp and position the shift control mechanism under test. The fixing component has a simple structure, occupies little space, operates quickly, and is inexpensive.
[0016] 3. The test component of this invention can determine whether the shift control mechanism is qualified by driving the reciprocating motion of the U-shaped test arm and using force sensors, angle sensors or displacement sensors. Qualified products can be calibrated. The structure is reasonably and ingeniously designed, and the testing and calibration are accurate and fast, resulting in high production efficiency.
[0017] 4. This invention uses the TCP / IP protocol and RJ45 interface to realize the information transmission and archiving of data and test parameters collected during the testing of the gear shift control mechanism 14, which facilitates information transmission and scientific management.
[0018] 5. This invention employs multiple sensors to detect whether the shift control mechanism, the first tray, the second tray, the lifting plate, and other mechanisms or components are in place, thus creating conditions for the controller program to control the next action of the relevant components.
[0019] 6. In this invention, the first pallet on the upper conveying track is conveyed to the lower conveying track via a lifting platform, and then conveyed to the upper conveying track via a lifting platform, so as to realize the reuse of the first pallet.
[0020] 7. This invention is applicable to the accurate testing and calibration of the shift control mechanism of HTEB and SZEA products, improving the efficiency and quality of testing and calibration. Attached Figure Description
[0021] Figure 1 This is one of the three-dimensional schematic diagrams of the present invention.
[0022] Figure 2 This is the second three-dimensional schematic diagram of the present invention.
[0023] Figure 3 This is a three-dimensional schematic diagram of the upper conveying track of the present invention.
[0024] Figure 4 This is a three-dimensional schematic diagram of the connection structure of the fifth cylinder and the blocking block of the present invention.
[0025] Figure 5 This is a three-dimensional schematic diagram of the lifting plate connection structure of the present invention.
[0026] Figure 6 This is a three-dimensional schematic diagram of the connection structure of the gripper at the end of the robotic arm of the present invention.
[0027] Figure 7 This is a three-dimensional schematic diagram of the energized component of the present invention.
[0028] Figure 8 This is a three-dimensional schematic diagram of the fixing component of the present invention.
[0029] Figure 9 This is a three-dimensional schematic diagram of the test component of the present invention. Detailed Implementation
[0030] The present invention, as a further optimization of the above technical solution, is further described below with reference to the accompanying drawings and specific embodiments. See also: Figures 1-9 : An online testing and calibration device for a vehicle gear shifting mechanism includes a workbench 10. A first tray 12 is mounted on an upper conveyor rail 6 on one side of the workbench 10, and a robotic arm 2 and a testing and calibration fixture 4 are mounted on the other side. The testing and calibration fixture 4 includes a second tray 13, a fixing component 8, a power supply component 3, and a testing component 4 capable of horizontal, vertical, and longitudinal movement. The robotic arm 2 can transfer a gear shifting mechanism 14 from the first tray 12 to the second tray 13 and vice versa. The test assembly 4 is placed on the first tray 12. Its test end is equipped with a U-shaped test arm 42 with its opening facing downwards. The inner sides of the two vertical arms 40 of the U-shaped test arm 42 are respectively equipped with a force sensor 41 for testing the displacement thrust of the gear selector rocker arm 15, an angle sensor for testing the rotation angle of the gear selector rocker arm 15, or a displacement sensor for testing the displacement distance. The reciprocating movement of the U-shaped test arm 42 can shift the gear selector rocker arm 15 of the gear shifting mechanism 14 from D to N and then to R (e.g., the gear shifting mechanism of HTEB and SZEA products). Select D, DN, O, RN, and R gears; D and DN are the two forward gears: these are the most commonly used gears in daily driving. After engaging, the transmission will automatically shift gears according to vehicle speed and throttle, achieving smooth forward movement; N is neutral: used to temporarily disconnect the power connection between the engine and transmission, commonly used for short-term stops (such as waiting at a red light) or when towing; when reversing, use the rearview mirror or camera system to avoid sudden acceleration to ensure safety; O or OD is overdrive, an extension of D gear, used at high speeds. During high-speed cruising, the overdrive gear is automatically locked to improve fuel economy. Generally, no manual operation is required, and the vehicle will automatically switch according to the vehicle speed. RN and R are two reverse gears: they are dedicated to reversing and require the vehicle to be completely stopped and the lever safety button to be pressed when engaging. The displacement angle, displacement stroke, and displacement thrust between the gears are tested, and the test data are compared with the standard values pre-stored in the controller. If the comparison result meets the requirements, it is directly calibrated online on the Hall element of the shift control mechanism 14. If the comparison result does not meet the requirements, an alarm is triggered.
[0031] The controller archives the number of tested and calibrated products, yield rate statistics, working hours statistics, performance test parameters, test data and image memory waveforms, test product part numbers, codes, and batch information collected during the testing of the shift control mechanism.
[0032] As a further optimization of the above technical solution, the controller adopts the TCP / IP protocol and RJ45 interface to realize the information transmission and storage of data and test parameters collected during the test of the gear shift control mechanism 14 across the network.
[0033] As a further optimization of the above technical solution, the robotic arm 2 is a six-axis robotic arm. The middle part of the mounting plate 24 is fixed on the rotating shaft 22 at the end of the robotic arm of the six-axis robotic arm 2. The two ends of the mounting plate 24 are respectively provided with first cylinders 23 to drive relative movement to clamp two grippers 25 of the shift control mechanism 14. The two grippers 25 are respectively provided with first sensors 20 to detect the presence of the shift control mechanism 14. The detection signal of the first sensor 20 is transmitted to the controller. The mounting plate 24 between the two grippers 25 is provided with an elastic clamping column 21. The elastic clamping column 21 can make the clamping position of the shift control mechanism 14 and its placement position on the first tray 12 and the second tray 13 accurate.
[0034] As a further optimization of the above technical solution, the fixing component 8 is provided with two lifting and rotating cylinders 84 on the bracket 85 on one side of the second tray 13. The end of the piston rod 83 extending upward beyond the lifting and rotating cylinder 84 is fixed with a transverse first cantilever 81. A pressure block 80 is provided on the lower surface of the outer end of the first cantilever 81. The first cantilever 81 can rotate 90 degrees with the piston rod 83. The pressure block 80 can be released or pressed against the shift control mechanism 14 as the first cantilever 81 and the piston rod 83 rise and fall. For safety, a limiting block 82 is provided on the bracket 85 of the two piston rods 83 to limit the inward rotation angle of the two first cantilever 81.
[0035] As a further optimization of the above technical solution, the power-conducting component 3 is a slide plate 31 driven by a second cylinder 32 that slides on a transverse slide rail 34 on a bracket 33 on one side of the second tray 13. A second cantilever 35 driven by a third cylinder 30 to move up and down is fixed on the bracket of the slide plate 31. A probe assembly 36 is provided at the lower outer end of the second cantilever 35, which can make electrical contact with the corresponding electrical contacts on the circuit board of the shift control mechanism 14. The probe assembly 36 is electrically connected to the controller. The probe assembly 36 consists of a plurality of probes on a mounting plate at the lower outer end of the second cantilever 35 and conductive wires that electrically connect the probes to the controller.
[0036] As a further optimization of the above technical solution, the test component 4 includes a first slider 49 driven by a first motor 51 mounted on a bracket 52 and sliding on a transverse slide rail 50; a second slider 45 driven by a second motor 47 mounted on a longitudinal slide rail 48 mounted on the first slider 49 and sliding on a longitudinal slide rail 48; and a third slider 43 driven by a third motor 46 mounted on a vertical slide rail 44 mounted on the second slider 45 and sliding on a vertical slide rail 44. The lower part of the third slider 43 is the test end, and the test end is provided with the U-shaped test arm 42.
[0037] As a further optimization of the above technical solution, a second sensor 62 for detecting the presence of the shift control mechanism 14 is provided on one side of the first tray 12 and the second tray 13, and the detection signal of the second sensor 62 is transmitted to the controller.
[0038] As a further optimization of the above technical solution, a barcode scanner 64 is provided on the workbench 10 on one side of the first tray 12 to scan the product QR code on the shift control mechanism 14, and the scanning signal of the barcode scanner 64 is transmitted to the controller.
[0039] As a further optimization of the above technical solution, a lower conveying rail 11 is provided on the lower side of the workbench 10, and a lifting platform driven by a fourth cylinder is provided at both ends of the upper conveying rail 6 and the lower conveying rail 11, so as to transfer the first tray 12 on the upper conveying rail 6 back to the upper conveying rail 6 via the lower conveying rail 11, so as to realize the reuse of the first tray 12. Both the upper conveying rail 6 and the lower conveying rail 11 are automatic speed-multiplying chains with adjustable width. The adjustable width is achieved by fixing one rail 61 of the automatic speed-multiplying chain on the slider 67, and using a synchronous belt drive to realize the synchronous rotation of multiple lead screws 60, thereby driving the rail 61 and the slider 67 to move synchronously on the slide rail 63, so as to realize the adjustable width of the automatic speed-multiplying chain, which can run first trays 12 of different widths. A third sensor is provided on the lifting platform to detect whether the shift control mechanism 14 is in position, and the detection signal of the third sensor is transmitted to the controller.
[0040] As a further optimization of the above technical solution, the workbench 10 is provided with a first tray 12 pause position 65. The entry side of the pause position 65 is provided with a fourth sensor 66 to sense whether the shift control mechanism 14 has entered, and the exit side is provided with a fifth sensor to detect whether the shift control mechanism 14 is in position and a blocking block 71 driven by a fifth cylinder 73 for lifting. The blocking block 71 is provided with a pneumatic or spring damping component 72 and an abutting roller 70. The lower side of the pause position 65 is provided with a lifting plate 76 driven by a sixth cylinder 77 for lifting. The lifting plate 76 is provided with a positioning pin 74 that matches the positioning hole on the first tray 12 and a sixth sensor 75 to sense whether the first tray 12 has been lifted into position. The detection signals of the fourth sensor 66, the fifth sensor, and the sixth sensor 75 are transmitted to the controller.
[0041] The first to sixth sensors and other sensors can be magnetic induction sensors or photoelectric induction sensors to detect whether the shift control mechanism, the first tray, the second tray, the lifting plate and other mechanisms or components are in place, so that the controller can control the next action of the relevant components.
[0042] The working process of this invention is as follows: The shift control mechanism to be tested is placed sequentially on the first tray 12 of the automated double-speed chain by a robotic arm or manually. Under the control of the controller, the first tray 12 carries the shift control mechanism to the stop position 65. One set of grippers of the robotic arm 2 clamps the shift control mechanism to be tested on the stop position 65 and rotates it to the second tray 13. The other set of grippers of the robotic arm 2 clamps the calibrated shift control mechanism on the second tray 13 and lifts it up. At the same time, the shift control mechanism to be tested is rotated to the second tray 13 and placed on the second tray 13. Then, the robotic arm 2 sends the calibrated shift control mechanism on the second tray 13 to the first tray 12 of the automated double-speed chain for delivery. Then, it clamps another shift control mechanism to be tested and moves it to the second tray 13. During this process, the testing component 4 has positioned and clamped the shift control mechanism to be tested. The power supply component connects the shift control mechanism to be tested with the controller. The controller is electrically connected. The U-shaped test arm 42 of the test component reciprocates to start the left and right rotation of the gear selection rocker arm 15 of the gear shifting control mechanism under test. The force sensor 41, angle sensor or displacement sensor on the U-shaped test arm 42 senses the pushing force, rotation angle or mechanical stroke of the gear selection rocker arm 15 corresponding to each gear and compares it with the standard value pre-stored in the controller. If the comparison result meets the requirements, it is directly calibrated online on the Hall element of the gear shifting control mechanism 14. If the comparison result does not meet the requirements, an alarm is triggered. Then, the robot arm 2 grabs the calibrated gear shifting control mechanism and lifts it to the first tray 12 of the automated double speed chain. The above actions are repeated to continuously test and calibrate the gear shifting control mechanism. The first tray 12 can be transported to the lower conveyor track 11 through the upper conveyor track 6 and the lifting platform. After the lower conveyor track 11 runs, it is transported to the upper conveyor track 6 through another lifting platform, realizing the reuse of the first tray 12.
[0043] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that simple substitutions or modifications can still be made to the technical solutions or technical features described in the foregoing embodiments, and these simple substitutions or modifications do not cause the essence of the corresponding technical solutions to deviate from the spirit and substance of the technical solutions of the embodiments of the present invention, and are still within the protection scope of the present invention.
Claims
1. A device for on-line testing and calibration of a gear shift control mechanism of a vehicle, comprising a workbench, characterized in that: The workbench has a first tray on an upper conveyor rail on one side and a robot arm and a test calibration fixture on the other side. The test calibration fixture includes a second tray, a fixing component, a power-conducting component, and a test component that can move laterally, longitudinally, and vertically. The robot arm can move the shift control mechanism from the first tray to the second tray and vice versa. The test end of the test component has a U-shaped test arm with an opening facing downwards. The inner sides of the two vertical arms of the U-shaped test arm are respectively equipped with a force sensor, an angle sensor, or a displacement sensor. The reciprocating movement of the U-shaped test arm can test the displacement angle, displacement stroke, and displacement thrust of the shift control mechanism's gear selection rocker arm from D gear to N gear and then to R gear. The test data is compared with the standard values pre-stored in the controller. If the comparison result meets the requirements, it is directly calibrated online on the Hall element of the shift control mechanism. If the comparison result does not meet the requirements, an alarm is triggered.
2. The online testing and calibration device for a vehicle gear shifting mechanism according to claim 1, characterized in that: The controller uses the TCP / IP protocol and RJ45 interface to realize the information transmission and storage of data and test parameters collected during the testing of the gear shifting mechanism across the network.
3. The online testing and calibration device for a vehicle gear shifting mechanism according to claim 1, characterized in that: The robotic arm is a six-axis robotic arm. The middle part of the mounting plate is fixed on the rotating shaft at the end of the robotic arm of the six-axis robotic arm. The two ends of the mounting plate are respectively provided with two grippers driven by the first cylinder to move relative to each other to clamp and hold the shift control mechanism. The two grippers are respectively provided with a first sensor to detect the presence of the shift control mechanism. The detection signal of the first sensor is transmitted to the controller. An elastic clamping column is provided on the mounting plate between the two grippers.
4. The online testing and calibration device for a vehicle gear shifting mechanism according to claim 1, characterized in that: The fixing component consists of two lifting and rotating cylinders mounted on a bracket on one side of the second tray. A first horizontal cantilever is fixed to the end of the piston rod extending upward from the lifting and rotating cylinders. A pressure block is provided on the lower surface of the outer end of the first cantilever. The first cantilever can rotate 90 degrees with the piston rod. The pressure block can be released or pressed against the shifting control mechanism as the first cantilever and the piston rod rise and fall.
5. The online testing and calibration device for a vehicle gear shifting mechanism according to claim 1, characterized in that: The power-conducting component consists of a slide plate that is slidably mounted on a transverse slide rail on a bracket on one side of the second tray. A second cantilever that is driven to move up and down by a third cylinder is fixed on the bracket of the slide plate. A probe assembly is provided at the lower outer end of the second cantilever that can make electrical contact with the corresponding electrical contacts on the circuit board of the shift control mechanism. The probe assembly is electrically connected to the controller.
6. The online testing and calibration device for a vehicle gear shifting mechanism according to claim 1, characterized in that: The test assembly includes a first slider mounted on a support and driven by a first motor to slide on a horizontal slide rail, a second slider mounted on a vertical slide rail and driven by a second motor to slide on a vertical slide rail, and a third slider mounted on a vertical slide rail and driven by a third motor to slide on a vertical slide rail. The lower part of the third slider is the test end, and the test end is provided with the U-shaped test arm.
7. The online testing and calibration device for a vehicle gear shifting mechanism according to claim 1, characterized in that: A second sensor is provided on one side of both the first tray and the second tray to detect the presence of the shift control mechanism, and the detection signal of the second sensor is transmitted to the controller.
8. The online testing and calibration device for a vehicle gear shifting mechanism according to claim 1, characterized in that: A barcode scanner is installed on the workbench on one side of the first tray to scan the product QR code on the shift control mechanism. The scanning signal from the barcode scanner is transmitted to the controller.
9. An online testing and calibration device for a vehicle gear shifting mechanism according to any one of claims 1-8, characterized in that: The workbench is equipped with a lower conveyor rail, and the upper and lower conveyor rails are equipped with lifting platforms driven by a fourth cylinder at both ends, so as to transfer the first pallet on the upper conveyor rail back to the upper conveyor rail via the lower conveyor rail, so as to realize the reuse of the first pallet. Both the upper and lower conveyor rails are automatic double-speed chains with adjustable width. The lifting platform is equipped with a third sensor to detect whether the shift control mechanism is in position, and the detection signal of the third sensor is transmitted to the controller.
10. The online testing and calibration device for a vehicle gear shifting mechanism according to claim 1, characterized in that: The workbench is equipped with a first tray pause position. On the entry side of the pause position, there is a fourth sensor to detect whether the shift control mechanism has entered. On the exit side, there is a fifth sensor to detect whether the shift control mechanism is in position and a blocking block driven by a fifth cylinder for lifting. The blocking block is equipped with pneumatic or spring damping components. On the lower side of the pause position, there is a lifting plate driven by a sixth cylinder for lifting. The lifting plate is equipped with a positioning pin that matches the positioning hole on the first tray and a sixth sensor to detect whether the first tray has been lifted into position. The detection signals from the fourth, fifth, and sixth sensors are transmitted to the controller.