Joint rotation angle measuring system of excavator in any posture

Abstract

The invention discloses a joint rotation angle measuring system of an excavator in any posture, which comprises a first tilt angle sensor, a second tilt angle sensor, a third tilt angle sensor, a fourth tilt angle sensor, a fifth tilt angle sensor, a vehicle-mounted controller and a display. The measuring devices are used for measuring the included angles between the measuring devices and the horizontal plane, are arranged on the balance weight side portion, the rear portion, the movable arm side, the bucket rod side and the bucket connecting rod of the excavator respectively, receive included angle information through a vehicle-mounted controller and calculate the included angles between all the parts of the excavator in different working states and the horizontal plane. Therefore, an overall posture model of the excavator can be constructed, so that a subsequent automatic excavation function can be conveniently realized. The system is simple in structure and simple in arrangement process, is not influenced by environmental pollution, is not easy to damage in a severe environment due to the fact that each tilt angle sensor is not provided with a relative moving part, can be used for a long time after being installed once, and has higher stability and reliability.

Description

Technical Field

[0001] The invention relates to the technical field of excavators, and in particular to a joint angle measurement system of an excavator in any posture. Background Art

[0002] At present, the application scenarios of unmanned excavators are becoming more and more extensive, and the requirements for intelligent excavation operations are increasing. Among them, in order to achieve precise operation control, how to obtain the posture of the excavator in real time has become a key technology. By obtaining the rotation angles of each joint of the excavator in real time, a real-time posture model of the excavator can be constructed to realize the automation and precise control of the excavation process, including precise control of key parts such as the excavator bucket, boom, and dipper rod, so that the excavator can automatically dig according to the preset path and depth, reducing errors and repeated operations. However, due to the structural characteristics of the excavator and the harsh working environment, several common solutions for collecting the rotation angles of the excavator joints currently have some significant shortcomings, which directly affect the measurement effect. For example, the angle encoder is used to measure the joint angle of the excavator. This method is to align the axis of the angle encoder with the joint shaft of the excavator and transmit the joint rotation of the excavator to the encoder through a mechanical connection. This method is simple and direct for measuring the joint angle, and the accuracy is also high, but the disadvantages are also obvious. On the one hand, due to the structural characteristics of the excavator and the precision of the encoder, this method puts forward high requirements on the installation accuracy of the sensor, resulting in more difficult installation. On the other hand, since the encoder and the mechanical connection part of the excavator have relative movement and are exposed to the outside, they are easily affected by the working environment, such as external mechanical shock and vibration, which causes the encoder to be deformed and damaged, and the accuracy is reduced. For another example, the excavator joint angle can be measured by using a wire sensor to measure the telescopic length of the hydraulic cylinder. This method is more intuitive to read the hydraulic cylinder data, and the excavator joint angle can be obtained by calculation, but this method is more complicated to arrange, and it is necessary to drill holes on the cylinder body, and the wire is easily contaminated in the working environment, so it will fail quickly. In summary, the several existing methods for measuring joint angles on excavators currently have defects such as complex layout, high installation difficulty, easy damage, high maintenance cost and poor practicality. Summary of the invention

[0003] In order to overcome the deficiencies of the prior art, an object of the present invention is to provide a joint angle measurement system for an excavator in any posture, which can reduce the difficulty of layout and improve stability and reliability.

[0004] To solve the above problems, the technical solution adopted by the present invention is as follows: a joint angle measurement system for an excavator in any posture, comprising a first inclination sensor, a second inclination sensor, a third inclination sensor, a fourth inclination sensor, a fifth inclination sensor, a vehicle-mounted controller and a display;

[0005] The first inclination sensor is arranged on the side of the counterweight of the excavator and is used to measure the pitch angle of the excavator body;

[0006] The second inclination sensor is arranged at the rear of the counterweight of the excavator and is used to measure the roll angle of the excavator body;

[0007] The third inclination sensor is arranged on the boom side of the excavator and is used to measure the angle between the boom of the excavator and the horizontal plane;

[0008] The fourth inclination sensor is arranged on the side of the dipper arm of the excavator and is used to measure the angle between the dipper arm of the excavator and the horizontal plane;

[0009] The fifth inclination sensor is arranged on the bucket connecting rod of the excavator, and is used to measure the angle between the bucket connecting rod of the excavator and the horizontal plane;

[0010] The vehicle-mounted controller is capable of receiving the measurement data of the first inclination sensor, the second inclination sensor, the third inclination sensor, the fourth inclination sensor and the fifth inclination sensor in real time, and calculating the rotation angle of each joint of the excavator in any posture according to the measurement value of each sensor, and sending the rotation angle information to the display for real-time display.

[0011] Compared with the prior art, the beneficial effect of the present invention is that the system can obtain the rotation angle and overall posture of each joint of the entire excavator by only arranging five inclination sensors and calculating; five inclination sensors are arranged on the excavator, all of which measure the angle with the horizontal plane, and are arranged on the counterweight side, rear, boom side, dipper side and bucket connecting rod of the excavator respectively, and the inclination data of the sensors of various parts of the excavator are received through the on-board controller and the real-time calculation is performed to obtain the real-time working status of the excavator, which can be used to construct the overall posture model of the excavator, so as to realize the subsequent automatic excavation function. The system has a simple structure and a simple arrangement process, and is not easily affected by the impact and pollution of the external harsh environment. Moreover, since the inclination sensors are tightly installed on the various parts of the excavator and there are no relatively moving parts, they are not easily damaged in harsh environments. They can be used for a long time after being installed once, and have high stability, economy and reliability, so they have strong practical value in engineering projects.

[0012] The above-mentioned joint angle measurement system of the excavator in any posture, the "calculating and obtaining the rotation angle of each joint of the excavator in any posture according to the measurement signal" comprises the following steps:

[0013] Step S100, taking the center position of the slewing support of the excavator as the origin, a coordinate system is established, wherein the front direction of the cab parallel to the horizontal plane is the Y axis, the horizontal right direction perpendicular to the Y axis is the X axis, and the upward direction perpendicular to the XOY plane is the Z axis;

[0014] Step S200, assuming that the angles obtained by the first tilt sensor, the second tilt sensor, the third tilt sensor, the fourth tilt sensor, and the fifth tilt sensor with the horizontal plane are sensorY, sensorX, sensorBoom, sensorStick, and sensorBucker respectively;

[0015] Step S300, calculate the joint angle θ1 between the excavator boom and the vehicle body in the Y-axis direction according to the following formula:

[0016]

[0017] Step S400, calculating the joint angle θ2 between the excavator boom and the dipper arm according to the following formula:

[0018]

[0019] Step S500, calculate the joint angle θ3 between the excavator arm and the bucket connecting rod according to the following formula:

[0020]

[0021] In the above-mentioned joint angle measurement system of the excavator in any posture, the installation direction of the first inclination sensor is parallel to the Y-axis direction, and the installation direction of the second inclination sensor is parallel to the X-axis direction;

[0022] The installation direction of the third inclination sensor is parallel to the first connecting line, wherein the first connecting line is a connecting line between the centers of the two connecting shafts of the boom on the vehicle body and the boom;

[0023] The fourth inclination sensor is installed in a direction parallel to the second connecting line, wherein the second connecting line is a connecting line between the centers of the two connecting shafts of the boom and the bucket;

[0024] The installation direction of the fifth inclination sensor is parallel to the length direction of the bucket connecting rod.

[0025] In the above-mentioned joint angle measurement system of the excavator in any posture, the measuring range of the first inclination sensor, the second inclination sensor, the third inclination sensor, the fourth inclination sensor and the fifth inclination sensor is -90° to 90°.

[0026] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a partial structural diagram of a measurement system according to an embodiment of the present invention, wherein the vehicle-mounted controller and the display are not shown.

[0028] Description of the accompanying drawings: 1-first inclination sensor, 2-second inclination sensor, 3-third inclination sensor, 4-fourth inclination sensor, 5-fifth inclination sensor, 6-counterweight of excavator, 7-boom, 8-arm, 9-bucket, 10 bucket connecting rod. DETAILED DESCRIPTION

[0029] The embodiments of the present invention are described in detail below. Figure 1 , an embodiment of the present invention provides a joint angle measurement system for an excavator in any posture, including a first inclination sensor 1, a second inclination sensor 2, a third inclination sensor 3, a fourth inclination sensor 4, a fifth inclination sensor 5, a vehicle-mounted controller and a display;

[0030] The first inclination sensor 1 is arranged on the side of the counterweight 6 of the excavator and is used to measure the pitch angle of the excavator body;

[0031] The second inclination sensor 2 is arranged at the rear of the counterweight 6 of the excavator and is used to measure the roll angle of the excavator body;

[0032] The third inclination sensor 3 is arranged on the side of the boom 7 of the excavator, and is used to measure the angle between the boom 7 of the excavator and the horizontal plane;

[0033] The fourth inclination sensor 4 is arranged on the side of the dipper arm 8 of the excavator, and is used to measure the angle between the dipper arm 8 of the excavator and the horizontal plane;

[0034] The fifth inclination sensor 5 is arranged on the bucket connecting rod 10 of the excavator, and is used to measure the angle between the bucket connecting rod 10 of the excavator and the horizontal plane;

[0035] The vehicle-mounted controller can receive measurement signals from the first inclination sensor 1, the second inclination sensor 2, the third inclination sensor 3, the fourth inclination sensor 4 and the fifth inclination sensor 5, and calculate the rotation angle of each joint of the excavator in any posture according to the measurement data according to the above formula, and send the rotation angle information to the display for display.

[0036] Compared with the existing technology, this system arranges five digital single-axis inclination sensors on the excavator, all of which measure the angle with the horizontal plane. They are arranged on the side of the counterweight 6 of the excavator, the rear of the counterweight 6, the side of the boom 7, the side of the dipper rod 8 and the digging bucket connecting rod 10, respectively. The vehicle controller receives the angle information and calculates the angle between each part of the excavator and the horizontal plane in different working conditions. This can be used to build the overall posture model of the excavator to facilitate the subsequent automatic excavation function. This system has a simple structure and a simple arrangement process. It is not affected by environmental pollution. Since each inclination sensor has no relatively moving parts, it is not easy to be damaged in harsh environments. It can be installed once and used for a long time. It has high stability, economy and reliability, and therefore has good practical value in engineering projects.

[0037] Furthermore, when arranging and installing five inclination sensors, first park the excavator on a flat ground, put down the bucket 9, and establish a virtual coordinate system with the center position of the excavator's slewing support as the origin, wherein the front direction of the cab parallel to the horizontal plane is the Y axis, the horizontal right direction perpendicular to the Y axis direction is the X axis, and the upward direction perpendicular to the XOY plane is the Z axis. The first inclination sensor 1 is installed on the side of the excavator counterweight 6, wherein the installation direction of the first inclination sensor 1 is parallel to the Y axis direction. The first inclination sensor 1 can detect the pitch angle of the excavator in real time. During installation, the first inclination sensor 1 can be powered on to ensure that it is installed as horizontally as possible to improve the measurement accuracy. A second inclination sensor 2 is installed at the rear of the counterweight 6 of the excavator, wherein the installation direction of the second inclination sensor 2 is parallel to the X-axis direction, and the second inclination sensor 2 can detect the roll angle of the excavator in real time. During installation, the second inclination sensor 2 can be powered on to ensure that it is installed as horizontally as possible to improve the measurement accuracy. The installation direction of the second inclination sensor 2 can also be made as perpendicular to the installation direction of the first inclination sensor 1 as possible with the help of an angle ruler. A third inclination sensor 3 is fixedly installed on the boom 7, and the installation direction of the third inclination sensor 3 is parallel to the first connecting line, wherein the first connecting line is the connecting line of the centers of the two connecting shafts of the boom 7 at the vehicle body and the bucket 8, and the third inclination sensor 3 is used to detect the angle between the boom 7 and the horizontal plane in real time. A fourth inclination sensor 4 is fixed on the bucket 8, and the installation direction of the fourth inclination sensor 4 is parallel to the second connecting line, wherein the second connecting line is the connecting line of the centers of the two connecting shafts of the bucket 8 at the boom 7 and the bucket 9, and the fourth inclination sensor 4 is used to detect the angle between the bucket 8 and the horizontal plane in real time. A fifth inclination sensor 5 is arranged on the bucket connecting rod 10. The installation direction of the fifth inclination sensor 5 is parallel to the length direction of the bucket connecting rod 10. It is used to detect the angle between the bucket connecting rod 10 and the horizontal plane in real time. The calculation method can be obtained through the interpolation method or the four-bar geometric relationship. The measuring range of the first inclination sensor 1, the second inclination sensor 2, the third inclination sensor 3, the fourth inclination sensor 4 and the fifth inclination sensor 5 is -90° to 90°. After the five inclination sensors are installed, the joint rotation angle of each part can be calculated, and then the rotation angle of each joint of the excavator in any posture in a sloped environment can be obtained in real time. It can also be used to construct an overall posture model of the excavator to facilitate the subsequent automatic excavation function.

[0038] The five inclination sensors are connected to the vehicle controller via the CAN bus. The rotation angle of each joint can be obtained by calculation, and displayed on the display for human-computer interaction, the rotation angle value of the excavator is displayed in real time, and the excavator posture model is constructed in real time. Furthermore, the above-mentioned "obtaining the rotation angle of each joint of the excavator in any posture by calculation based on the measurement signal" includes the following steps:

[0039] Step S100, taking the center position of the slewing support of the excavator as the origin, a virtual coordinate system is established, wherein the front direction of the cab parallel to the horizontal plane is the Y axis, the horizontal right direction perpendicular to the Y axis is the X axis, and the upward direction perpendicular to the XOY plane is the Z axis;

[0040] Step S200, assuming that the angles obtained by the first tilt sensor 1, the second tilt sensor 2, the third tilt sensor 3, the fourth tilt sensor 4, and the fifth tilt sensor 5 with the horizontal plane are sensorY, sensorX, sensorBoom, sensorStick, and sensorBucker respectively;

[0041] Step S300, calculate the joint angle θ1 between the excavator boom 7 and the vehicle body in the Y-axis direction according to the following formula:

[0042]

[0043] Step S400, calculating the joint angle θ2 between the excavator boom 7 and the dipper arm 8 according to the following formula:

[0044]

[0045] Step S500, calculating the joint angle θ3 between the excavator arm 8 and the bucket connecting rod 10 according to the following formula:

[0046]

[0047] After installing the five inclination sensors, the position acquisition calibration and testing of each inclination sensor is carried out, and the vehicle controller in the cockpit is connected through the CAD bus, and the display is connected to the vehicle controller. The algorithm program related to the above calculation process is downloaded to the vehicle controller. After the excavator is powered on, the processing of each inclination sensor can be obtained in real time and displayed on the display. The structure and other functions of the vehicle controller and the display can refer to the existing technology. Figure 1 Not shown in .

[0048] The components of this system are simple. In terms of the number and types of sensors used, only five inclination sensors are used, and the rotation angles and overall postures of the joints of the entire excavator can be obtained through calculation. Compared with angle encoders, inclination sensors are easier to install, do not require external moving parts such as pull rods, and are not easily affected by external environmental pollution. Compared with the use of wire sensors, the layout of this system is simpler and is also not affected by environmental pollution. It has higher stability and reliability.

[0049] It should be noted that in the description of the present invention, if there are any orientation descriptions, such as up, down, front, back, left, right, etc., the orientations or positional relationships indicated are all based on the orientations or positional relationships shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed or operated in a specific orientation, and cannot be understood as a limitation on the present invention.

[0050] The above-mentioned embodiments are only preferred embodiments of the present invention and cannot be used to limit the scope of protection of the present invention. Any non-substantial changes and substitutions made by technicians in this field on the basis of the present invention shall fall within the scope of protection required by the present invention.

Claims

1. A joint angle measurement system for an excavator in any posture, characterized in that: It comprises a first inclination sensor (1), a second inclination sensor (2), a third inclination sensor (3), a fourth inclination sensor (4), a fifth inclination sensor (5), a vehicle-mounted controller and a display; The first inclination sensor (1) is arranged on the side of the counterweight (6) of the excavator and is used to measure the pitch angle of the excavator body; The second inclination sensor (2) is arranged at the rear of the counterweight (6) of the excavator and is used to measure the roll angle of the excavator body; The third inclination sensor (3) is arranged on the side of the boom (7) of the excavator and is used to measure the angle between the boom (7) of the excavator and the horizontal plane; The fourth inclination sensor (4) is arranged on the side of the dipper arm (8) of the excavator and is used to measure the angle between the dipper arm (8) of the excavator and the horizontal plane; The fifth inclination sensor (5) is arranged on the bucket connecting rod (10) of the excavator and is used to measure the angle between the bucket connecting rod (10) of the excavator and the horizontal plane; The vehicle-mounted controller is capable of receiving measurement data from the first inclination sensor (1), the second inclination sensor (2), the third inclination sensor (3), the fourth inclination sensor (4) and the fifth inclination sensor (5) in real time, and calculating the rotation angle of each joint of the excavator in any posture based on the measurement values ​​of each sensor, and sending the rotation angle information to a display for real-time display.

2. The joint angle measurement system for an excavator in any posture according to claim 1, characterized in that: The "calculating and obtaining the rotation angle of each joint of the excavator in any posture according to the measurement signal" comprises the following steps: Step S100, taking the center position of the slewing support of the excavator as the origin, a coordinate system is established, wherein the front direction of the cab parallel to the horizontal plane is the Y axis, the horizontal right direction perpendicular to the Y axis is the X axis, and the upward direction perpendicular to the XOY plane is the Z axis; Step S200, assuming that the angles obtained by the first tilt sensor (1), the second tilt sensor (2), the third tilt sensor (3), the fourth tilt sensor (4), and the fifth tilt sensor (5) with the horizontal plane are sensorY, sensorX, sensorBoom, sensorSti ck, and sensorBucker respectively; Step S300, calculate the joint angle θ1 between the excavator boom (7) and the vehicle body in the Y-axis direction according to the following formula: Step S400, calculating the joint angle θ2 between the excavator boom (7) and the dipper arm (8) according to the following formula: Step S500, calculating the joint angle θ3 between the excavator arm (8) and the bucket connecting rod (10) according to the following formula:

3. The joint angle measurement system of an excavator in any posture according to claim 2 is characterized in that: The installation direction of the first inclination sensor (1) is parallel to the Y-axis direction, and the installation direction of the second inclination sensor (2) is parallel to the X-axis direction; The installation direction of the third inclination sensor (3) is parallel to the first connecting line, wherein the first connecting line is a connecting line between the centers of the two connecting shafts of the boom (7) on the vehicle body and the arm (8); The fourth inclination sensor (4) is installed in a direction parallel to the second connecting line, wherein the second connecting line is a connecting line between the centers of the two connecting shafts of the boom (7) and the bucket (9) of the dipper arm (8); The installation direction of the fifth inclination sensor (5) is parallel to the length direction of the bucket connecting rod (10).

4. The joint angle measurement system of an excavator in any posture according to claim 1, characterized in that: The measuring ranges of the first inclination sensor (1), the second inclination sensor (2), the third inclination sensor (3), the fourth inclination sensor (4) and the fifth inclination sensor (5) are -90° to 90°.

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