CN114152218A

CN114152218A - Ice and snow protective equipment home range measuring device

Info

Publication number: CN114152218A
Application number: CN202111307000.2A
Authority: CN
Inventors: 陈先中; 王丽君; 侯庆文; 毛吉炀
Original assignee: University of Science and Technology Beijing USTB
Current assignee: University of Science and Technology Beijing USTB
Priority date: 2021-11-05
Filing date: 2021-11-05
Publication date: 2022-03-08
Anticipated expiration: 2041-11-05
Also published as: CN114152218B

Abstract

The invention provides a device for measuring the moving range of an ice and snow protective tool, and belongs to the technical field of angle measurement of protective tools. The device comprises a measuring module, a control module, a rack module and a motion module, wherein the motion module is installed on the rack module, the motion module is controlled by the control module, and the measuring module is arranged above the motion module. The motion module comprises an artificial limb, a connecting rod, a motor, a gear ring and a universal wheel, the rack module comprises a fixed rack and a detachable large arm base, the measuring module positions the motor through vision, the position of the motor is tracked in real time by combining an image processing technology, and an included angle of the large arm and the small arm on the horizontal plane is analyzed. The device simple structure detects target object, analysis angle through the method of machine vision, and is nimble in the use, compares with traditional physics ruler and mechanical measurement, has improved measuring equipment's intelligent level.

Description

Ice and snow protective equipment home range measuring device

Technical Field

The invention relates to the technical field of angle measurement of protectors, in particular to a device for measuring the moving range of an ice and snow protector.

Background

In recent years, with the development of ice and snow sports, the domestic demand for elbow protection is increasingly vigorous. The quality of the produced goods is not as good as that of foreign merchants due to the falling-behind detection technology of domestic ice and snow elbow pad manufacturers. The measuring equipment and the measuring method are developed by depending on a key parameter testing technology and equipment research and development of a wearable ice and snow sports equipment sports efficiency of a key item of a national key research and development plan of the department of science and technology, and aim to efficiently and accurately measure the ice and snow elbow guard angle and further measure the test indexes of the moving range and the protection range of the ice and snow elbow guard.

Elbow and knee are the main position of sports injury in ice and snow motion, strengthen the performance of protective equipment and can effectually ensure sportsman's personal safety and activity freedom. The protection performance of the protective clothing is embodied that when the protective clothing is impacted by external force, reverse force is provided to reduce the rotation angle of limbs of the protective clothing, so that joint dislocation is avoided; the activity of protective equipment can be embodied when sportsman's limbs rotate, and the protective equipment does not hinder its rotation as far as possible, and the limbs are better at equal moment initiative turned angle big more. At present, no method specially aiming at the angle performance test of the ice and snow protective tool exists, and the following methods are mainly used in the prior art of the angle test of other occasions or general scenes:

1. in a laser angle measuring device for an optical crystal, a mode of directly irradiating laser on a scale plate is essentially utilized to read out an angle to be measured. The measuring equipment disclosed by the invention adopts a machine vision method to identify key points and then calculates the angle, so that the angle measuring precision is not influenced due to the deviation of the distance between the measured piece and the laser, and the angle can be automatically read after the image analysis, so that the measurement is more efficient.

2. The camshaft angle measuring instrument has the advantages that the angle detection efficiency is improved by arranging a plurality of cam laser measuring heads, the cam provided with the laser measuring heads is driven to measure, and the angle is output by combining an encoder. In contrast, the present invention has a simple structure without considering the composite error introduced by multiple measurement units. In addition, because the artificial limb needs to replace different protective devices when the angle of the ice and snow protective device is measured, the measuring method has a simple structure and is more suitable for wearing the protective device.

3. The angle measuring device provided by the horizontal universal angle measuring device and the measuring method is essentially used for realizing real-time measurement of angles in any horizontal inclination direction by utilizing a single-axis angle sensor and a gravity pendulum. Compared with the prior art, the camera for measuring is small in size and easy to popularize in other occasions needing angle measurement.

4. The corner testing device is essentially characterized in that an angle testing is carried out after an angle sensor device is installed on an input shaft and an output shaft. But the factors such as the size of the angle sensor, wiring and the like are limited, and the artificial limb model is not suitable for being implanted.

5. The angle detecting device for turbocharger test has magnetized sensor with magnetized detecting probe to detect magnetized columns and magnetic sensor angle obtained based on the number of polar passing times. The method based on machine vision can measure any angle, and belongs to stepless measurement.

Generally, compared with the universal angle measuring equipment, the angle measuring equipment is simple in structural design and high in automation and intelligence degree, the angle measuring equipment only needs one sensing detector and can be an RGB (red, green and blue) camera, a depth camera or a laser radar, and the like, and the angle measuring method is more suitable for non-contact measurement of the angle of the ice and snow protective clothing. The device is controllable force equipment, force can be exerted at the longest position of an arm (palm), only the torque value output by a motor needs to be controlled, the torque value can be converted into the torque exerted on the artificial limb through gear meshing, and the force exerting device can be larger in force due to the long arm, so that very large torque can be generated by small force, and meanwhile, a force action point is moved up to the palm position, so that the force exerting device can be larger, low in cost and strong in controllability. And if the traditional idea is to place the torque motor at the elbow position of the arm, the torque motor is required to be small in size, the wearing of the protective tool cannot be influenced, the cost is high, and the torque is difficult to increase. Compared with the traditional method for measuring the angle by using a physical ruler, the intelligent method is characterized in that the image shot by the measuring module is identified, and the angle value required to be measured is analyzed. The angle-based test is used for evaluating whether the protector is qualified or not.

Disclosure of Invention

The invention provides a convenient device for measuring the movable range of the ice and snow protective clothing, aiming at solving the problem that the universal angle measurement is not suitable for the angle test of the ice hockey protective clothing.

The device comprises a measuring module, a control module, a rack module and a motion module, wherein the motion module is installed on the rack module, the motion module is controlled by the control module, and the measuring module is arranged above the motion module.

The motion module comprises an artificial limb, a connecting rod, a motor, a gear and a universal wheel, the frame module comprises a bottom plate, a gear ring, a fixed frame and a large arm base, the fixed frame is fixed on the bottom plate, the gear ring is fixed on the bottom plate through a countersunk head bolt, one end of the artificial limb is fixed on the fixed frame through the large arm base, the other end of the artificial limb is connected with the motor through the connecting rod, the universal wheel is installed at the bottom of the motor installation seat, the gear is connected with a motor shaft through a key in an interference fit mode, the motor drives the gear at the lower portion of the motor, and the gear is meshed with the gear ring.

The measuring module is one of an RGB camera, an RGB-D camera and a radar based on machine vision.

The artificial limb is an arm model or a leg model, and when the artificial limb is the arm model, the connecting rod is connected with the small arm and the motor.

The large arm base can be detached.

The device is used for the test of protective equipment performance, and artificial limb length is greater than protective equipment cover length, and the artificial limb minimum contraction angle is 30, and the biggest extension angle is 200.

The artificial limb is made of hollow aluminum alloy, and a bearing is arranged at the rotation center of the artificial limb.

When the angle of the ice and snow protective tool is measured, a minimum angle alpha and a maximum angle beta are recorded when the artificial limb forearm or the shank end rotates clockwise to a limit position, and the angle range of the protective tool is determined.

The technical scheme of the invention has the following beneficial effects:

in the scheme, the measuring module positions the motor through vision, tracks the position of the motor in real time by combining an image processing technology, and analyzes the included angle of the large arm and the small arm on the horizontal plane. The device simple structure detects target object, analysis angle through the method of machine vision, and is nimble in the use, compares with traditional physics ruler and mechanical measurement, has improved measuring equipment's intelligent level.

The invention has exquisite and replaceable artificial limb, external drive motor and simple frame design, and is beneficial to production and manufacture; the intelligent image recognition technology detects the real-time position of a motor connected with the artificial limb, and calculates the angle by combining the fixed part position (big arm, elbow or thigh, knee) of the artificial limb, as shown in figure 2; the artificial limb can simulate the rotation of the human limb under the drive of an external motor through the torque control of the control module. Compared with the traditional general angle measurement method, the angle measurement method is more suitable for measuring the angle of the ice and snow protective tool and can utilize the equipment to evaluate the angle performance of the protective tool.

Drawings

Fig. 1 is a schematic structural view of a device for measuring the range of motion of an ice and snow protective tool according to the present invention;

FIG. 2 is a diagram illustrating the range of angles over which the arm model of the present invention can rotate;

FIG. 3 is a diagram of the distance between the motor and the camera when the RGB-D camera or radar is selected as the measuring module of the present invention;

FIG. 4 shows the range of motion and the range of protection of the device of the present invention measured at different output torques of the motor;

FIG. 5 is a flow chart of a method for testing the critical elbow guard performance of the present invention;

FIG. 6 shows the range of angles that can be achieved with a prosthesis wearing the protector under different torque drives;

fig. 7 is a three-dimensional view of the ice and snow protective tool movement range measuring device of the present invention;

FIG. 8 is a schematic illustration of the torque experienced by an unprotected lower prosthesis in accordance with an embodiment of the present invention;

FIG. 9 is a flowchart of calculating the torque applied to the prosthesis according to an embodiment of the present invention;

FIG. 10 is a flow chart of the RGB camera angle measurement in the embodiment of the present invention.

Wherein: 1-a measurement module; 2-a control module; 3-a rack module; 4-a motion module; 5-artificial limb; 6-connecting rod; 7-a motor; 8-a gear ring; 9-universal wheels; 10-fixing the frame; 11-big arm base.

Detailed Description

In order to make the technical problems, technical solutions and advantages of the present invention more apparent, the following detailed description is given with reference to the accompanying drawings and specific embodiments.

The invention provides a device for measuring the moving range of an ice and snow protective tool.

As shown in fig. 1 and 7, the apparatus includes a measuring module 1, a control module 2, a frame module 3, and a moving module 4, the moving module 4 is mounted on the frame module 3, the moving module 4 is controlled by the control module 2, and the measuring module 1 is disposed above the moving module 4.

The motion module 4 comprises an artificial limb 5, a connecting rod 6, a motor 7, a gear and a universal wheel 9, the rack module comprises a bottom plate, a gear ring 8, a fixed rack 10 and a large arm base 11, the fixed rack 10 is fixed on the bottom plate, the gear ring 8 is fixed on the bottom plate through a countersunk head bolt, one end of the artificial limb 5 is fixed on the fixed rack 10 through the large arm base 11, the other end of the artificial limb is connected with the motor 7 through the connecting rod 6, the universal wheel 9 is installed at the bottom of a mounting seat of the motor 7, the motor 7 drives the gear at the lower part of the mounting seat, and the gear is meshed with the gear ring.

The measurement module is one of an RGB camera, an RGB-D camera and a radar based on machine vision, positions the motor 7 through vision, tracks the position of the motor 7 in real time by combining an image processing technology, and analyzes an included angle of a large arm and a small arm in the artificial limb on a horizontal plane (if the artificial limb is a leg model, the included angle of a thigh and a shank is obtained).

The artificial limb 5 is an arm model or a leg model, when the artificial limb is the arm model, the connecting rod 6 is connected with the small arm and the motor 7, the rotary motion of the motor 7 is converted into the circular motion concentric with the gear ring by the engagement of the gear on the output shaft of the motor 7 and the fixed gear ring, and the output torque of the motor 7 is converted into the torque always acting on the small arm.

The motor 7 can output given torque and measure real-time torque under the control of the control module 2, and the active telescopic motion of the arm and the passive motion of the external torque with different sizes and directions acting on the forearm are simulated through the torque output with different sizes.

The large arm base can be disassembled, and artificial limbs 5 with different sizes can be replaced according to the size of a test object.

When the artificial limb is an arm model, the large arm and the base are in threaded connection in the detachable design of the arm model, and a pair of hole shafts are designed at the connection part of the large arm and the base to be matched, so that the stress is not limited to screws for connection. The large arm and the small arm are connected by screws and nuts, and a pair of deep groove ball bearings are arranged on the screws and used for reducing the rotation resistance. In order to reduce the load of the base, the big arm and the small arm are both designed to be hollow, and the length of the big arm and the small arm is slightly longer than the length which needs to be covered when the elbow pad is worn.

When the artificial limb is an arm model, the device is used for testing the performance of the protective device, which is shown in the fact that the device can reach the range of the angle of the human arm model injured by external impact force, the designed minimum retractable angle is 30 degrees and is smaller than the maximum retractable angle of the human arm; the maximum stretching angle is 200 degrees and is larger than the maximum stretching angle of the arm of the human body.

Under the control of the control module 2 mainly comprising the servo driver, the motor 7 can limit the output torque of the motor, and the artificial limb 5 can rotate at a set torque value through the transmission system. When the set value is small, the autonomous motion of the artificial limb 5 can be simulated; when the set value is large, the passive rotation under the action of external torque can be simulated.

In the moment control, the output torque amplitude limiting control is carried out on the motor through the servo driver, and the moment control acting on the artificial limb is further realized through the transmission of the gear ring. The servo motor and the control module form a closed-loop control loop through an encoder of the servo motor.

The control mode is in the speed control mode and the torque amplitude limiting control of the driver, and the maximum value N of the torque of the control motor is required to be larger than the idling torque N for ensuring the rotation of the motor₀The moment of the artificial limb without the protector is shown as the figure8, due to the friction of the transmission device, the moment borne by the prosthesis during the rotation process is slightly larger than iN₀Until the maximum value iN, due to the resistance of the limb, the extreme position at which the prosthesis can rotate is reached.

The control loop controls the torque output of the motor through the driver, and the motor feeds back the actual output torque to the driver. The measurement software on the computer communicates with the driver to read the torque information of the real motor, and the calculated torque value M ═ iN of the prosthesis is the actual torque measured value, as shown iN FIG. 9.

The flow of the machine vision angle measurement method using an RGB camera as an example is shown in fig. 10.

In the actual design, the artificial limb is made of hollow aluminum alloy, so that the artificial limb is light and has good impact resistance, and is suitable for testing the performance of the protective device. In addition, the bearing is added in the rotating center, so that the rotating resistance is reduced.

Meanwhile, the artificial limb 5 can be popularized under the non-motor drive, and the pull rod is driven to do circular motion by the gravity of the weight through the transmission of the fixed pulleys arranged at the two ends of the gear ring.

In practical application, when an RGB camera is used for measurement, the horizontal distance R between the rotation center and the motor 7 is selected as a reference in machine vision, the position of the motor 7 is identified through a pixel matching method, and the possibility weight of a target on the distance R from the rotation center is increased in the process.

When measuring with an RGB-D camera (or radar) (as shown in fig. 3), the machine vision uses the linear distance L between the camera and the motor 7 as a reference, where H is the height difference between the measurement module and the rotation center of the prosthesis, D is the distance between the measurement module and the recognition target (motor), and R is the distance between the recognition target and the rotation center. The distance RGB-D camera is measured by binocular parallax (radar is measured by continuous frequency modulated waves). The probability weight of the target on the distance L from the rotation center is increased when the motor position is identified by using the pixel matching method.

And when the angle is measured, the motor 7 is identified by combining pixel matching and then returns to the center coordinate thereof, and the included angle of the elbow guard is calculated by the center coordinate, the elbow and the coordinate of the other end point of the central line of the big arm. Compared with a method for searching a target object in an image through a deeply learned network model, the design is easier to popularize and apply because part of fixing parts (elbows and large arms) are completed by calibration and the calculation complexity is far less than that of the network searching model, so that the requirements on lower delay and lower calculation force on equipment are met in practical application.

When the ice and snow protective tool is used for measuring the angle, the degree of motion resistance is low when the arms of a wearer stretch due to wearing the ice and snow protective tool, namely, the wearer actively bends, and the larger the angle motion range during arm stretching motion is, the better the angle motion range is (the smaller moment during active motion); the wearer should be protected from internal fracture and external dislocation by the external traumatic impact moment, i.e. the angle protection range cannot be too large (large moment during passive exercise).

When the angle of the ice and snow protective tool is measured, a minimum angle alpha and a maximum angle beta are recorded when the artificial limb forearm or the shank end rotates clockwise to a limit position, and the angle range of the protective tool is determined. As shown in FIG. 4, the performance index, M, of the motor 7 can be measured according to the magnitude of the torque output by the motor₀Is a small moment and is used for simulating the rotating moment of human limbs under the active will, M₁The moment is large and represents the passive rotating moment under the impact of external force in the movement, and at the moment, the limb has the risk of movement injury; the measured performance index includes the range of motion (alpha)₀，β₀) And protective scope (alpha)₁，β₁) Wherein α is₀And beta₀Respectively the minimum and maximum angle of movement, alpha₁And beta₁Respectively the minimum angle and the maximum angle of the protective range.

As shown in figure 2, the rotation angle range of the lower arm actively pulled by the motor 7 is larger than the angle range of normal rotation of a human body, so that whether the rotation angle range exceeds the normal rotation angle range under elbow guard protection can be visually seen, and the occasion of elbow guard performance testing is matched.

As shown in fig. 5, the knee pad performance test method can also be generalized to the knee pad performance test method after the artificial limb of the arm model is replaced by the thigh and calf model.

The following description is given with reference to specific examples.

After the artificial limb 5 is selected as an arm model and the measurement module 1 is an RGB camera, elbow protection angle and performance evaluation are tested through an example.

In the preparation stage, an arm model with one size is selected, the large arm is fixed on the large arm base 11, and the small arm is connected with the connecting rod 6 and then the elbow pad is worn. The camera picture can be adjusted through a preview picture of the test software, and the elbow and large arm positions can be calibrated. The elbow is concentric with a calibration circle in a preview picture, and the central line of the large arm is superposed with the calibration central line.

After the measurement is started, the camera is shot into an arm model picture to identify and analyze the angle. Therefore, the moving range and the protection range of the elbow pad can be measured by the following measuring method.

And (4) testing the range of motion, namely testing the range of the angle of rotation of the forearm under the autonomous swing after the user wears the protective equipment. First, the torque value applied to the forearm is controlled, for example, the torque output of the motor 7 is controlled to be N equal to 50Nmm, the torque M applied to the forearm is controlled to be iN, and the moment is 2000Nmm, at this time, the transmission ratio i is 40: 1, the length L of the forearm is 400mm, and the equivalent F is equal to F₀A force of 5N M/L acts on the tip of the forearm.

Secondly, the motor 7 is rotated counterclockwise under the moment to make the small arm rotate (clockwise) opposite to the large arm, and the angle between the large arm and the small arm which can reach the position record is the minimum angle alpha of the movable range₀；

Then, the motor 7 is stopped rotating, the motor 7 is rotated clockwise under the action of the moment, and the small arm is rotated counterclockwise to the maximum angle beta of the movable range₀。

Stopping the measurement, and measuring the moving range of (alpha)₀，β₀)。

And further, testing the protection range, namely testing the angle range of the forearm passively rotating under the external impact force after the user wears the protector. The set value is larger when the torque applied to the small arm is controlled, for example, the torque output of the motor is controlled to be 1Nm, and the torque applied to the small arm is 40 Nm.

Under the action of the moment, the protection range (alpha) is measured by using the same method as the movable range test₁，β₁)。

As shown in fig. 6, in (α)₀，β₀) The inner part is a movable range, so that the protective clothing can not block the movement;in (alpha)₁，α₀)∪(β₀，β₁) The inner part is a protection area, and the elbow guard plays a role in protection, so that the arm is prevented from being injured under the condition of high torque; at (0, alpha)₁)∪(β₁And, when the elbow guard is not sufficiently protected, the arm will be injured.

While the foregoing is directed to the preferred embodiment of the present invention, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the appended claims.

Claims

1. The utility model provides an ice and snow protective equipment home range measuring device, its characterized in that includes measurement module, control module, frame module and motion module, and the motion module is installed in the frame module, and the motion module passes through control module control, and measurement module sets up in the motion module top.

2. The ice and snow protective equipment range of motion measuring device of claim 1, characterized by, the motion module includes artificial limb (5), tie rod (6), motor (7), gear and universal wheel (9), the frame module includes the bottom plate, ring gear (8), fixed frame (10) and big arm base (11), fixed frame (10) are fixed on the bottom plate, gear ring gear (8) are fixed on the bottom plate through countersunk bolt, artificial limb (5) one end is fixed on fixed frame (10) through big arm base (11), the other end passes through tie rod (6) and connects motor (7), universal wheel (9) are installed to motor (7) mount pad bottom, motor (7) drive its lower gear, the gear meshes with the ring gear outward.

3. An ice and snow protective clothing range of motion measuring device of claim 1 wherein the measuring module is one of a machine vision based RGB camera, RGB-D camera, radar.

4. An ice and snow protector range of motion measuring device according to claim 2 characterized by the prosthesis (5) being an arm model or a leg model, in the case of an arm model, the link (6) connecting the lower arm and the motor (7).

5. An ice and snow protective clothing range of motion measuring device of claim 2 wherein the large arm base is detachable.

6. An ice and snow protector range of motion measuring device as claimed in claim 4 wherein the device is for protector performance testing when the prosthesis is a model arm, the prosthesis length is greater than the protector cover length, the prosthesis minimum retraction angle is 30 ° and the maximum extension angle is 200 °.

7. An ice and snow protector range of motion measuring device as claimed in claim 2 wherein the prosthesis is made of hollow aluminium alloy and the prosthesis centre of rotation is provided with a bearing.

8. The ice and snow supporter movement range measuring device according to claim 1, wherein when measuring the ice and snow supporter angle, the supporter angle range is determined by recording a minimum angle α and a maximum angle β in a counterclockwise direction by rotating the prosthetic forearm or calf end clockwise to an extreme position.