A six-component portable force measurement platform suitable for the field of sports rehabilitation

Abstract

A six-component portable force measuring platform suitable for the field of sports rehabilitation belongs to the technical field of measuring equipment. The present invention aims to solve the problem that the charge of the piezoelectric crystal of the force measuring platform decays over time, resulting in large errors in long-term measurements. It includes an upper plate, a spoke-type sensor includes an inner connecting column and an outer connecting sleeve coaxially arranged inside and outside, the outer connecting sleeve and the inner connecting column are connected by four strain beams, a plurality of strain gauges are attached to the strain beam, and the plurality of strain gauges respectively form a bridge for measuring transverse force, lateral force and longitudinal force, the outer connecting sleeves of the four spoke-type sensors are respectively connected to the four corners of the upper plate, the inner connecting column is spherically hinged to the ball socket base, and the present invention measures the force of the upper plate through the micro-strain of the strain beam, thereby solving the problem that the charge of the piezoelectric crystal of the force measuring platform decays over time, resulting in large errors in long-term measurements.

Description

Technical Field

[0001] The invention belongs to the technical field of measuring equipment, and in particular relates to a six-component portable force measuring platform suitable for the field of sports rehabilitation. Background Art

[0002] Mechanical testing is widely used in many fields such as aviation and aerospace. According to the measurement mechanism, there are two main types: strain measurement and piezoelectric measurement. The principle of piezoelectric measurement is that some crystal materials generate electric charges under the action of force, and the force value is obtained by measuring the charge. The principle of strain measurement is that the material body deforms under the action of force, and the force value is obtained by measuring this deformation. Most force measuring equipment has evolved various structures based on the above mechanism to meet the testing needs of different scenarios. Among them, the force measuring platform structure is mainly used in the fields of object weighing, physical education, rehabilitation medicine, sports bionics, etc. At present, the force measuring platform in this field is mainly a product based on piezoelectric measurement. This product has the advantage of simple structure and easy design, but the main disadvantage of this product is that the charge of the piezoelectric crystal will decay over time, resulting in large errors in long-term measurements. Summary of the invention

[0003] The purpose of the present invention is to provide a six-component portable force measuring platform suitable for the field of sports rehabilitation, so as to solve the problem that the charge of the piezoelectric crystal of the force measuring platform decays over time, resulting in large errors in long-term measurements. The technical solution adopted by the present invention is as follows:

[0004] A six-component portable force measurement platform suitable for the field of sports rehabilitation, comprising an upper plate, a junction box, a spoke-type sensor, a universal hinge, a pressure cover and a ball and socket base;

[0005] The spoke-type sensor comprises an inner connecting column and an outer connecting sleeve which are coaxially arranged inside and outside. Four process connecting grooves which penetrate from top to bottom are evenly arranged on the circumference of the inner wall of the outer connecting sleeve. Four rectangular thin walls are arranged in the four process connecting grooves one by one. The two sides of the rectangular thin walls are respectively connected to the two side walls of the process connecting grooves. The rectangular thin walls are parallel to the bottom surfaces of the corresponding process connecting grooves. The inner connecting column is connected to the rectangular thin walls through strain beams. The strain beams are perpendicular to the corresponding rectangular thin walls, and the strain beams are perpendicular to the inner connecting column.

[0006] The strain beam is a rectangular column beam, and the four strain beams are respectively located on the left side, right side, front side and rear side of the inner connecting column. The first strain gauge is pasted on the upper side of the strain beam on the rear side, the third strain gauge is pasted on the lower side, the ninth strain gauge is pasted on the left side, and the twelfth strain gauge is pasted on the right side. The second strain gauge is pasted on the upper side of the strain beam on the front side, the fourth strain gauge is pasted on the lower side, the tenth strain gauge is pasted on the left side, and the eleventh strain gauge is pasted on the right side. The fifth strain gauge is pasted on the rear side of the strain beam on the left side, The seventh strain gauge is pasted on the front side surface, the sixth strain gauge is pasted on the rear side surface of the strain beam on the right side, and the eighth strain gauge is pasted on the front side surface. The first strain gauge, the third strain gauge, the second strain gauge and the fourth strain gauge are electrically connected in sequence to form a Wheatstone bridge, which is marked as U1. The fifth strain gauge, the seventh strain gauge, the sixth strain gauge and the eighth strain gauge are electrically connected in sequence to form a Wheatstone bridge, which is marked as U3. The ninth strain gauge, the eleventh strain gauge, the tenth strain gauge and the twelfth strain gauge are electrically connected in sequence to form a Wheatstone bridge, which is marked as U2.

[0007] The upper end surface of the ball socket base is provided with a stepped groove, the bottom surface of the stepped groove is provided with a hemispherical groove, the pressure cover is adapted to the stepped groove, the lower end surface of the pressure cover is provided with a spherical table-shaped groove, the top surface of the spherical table-shaped groove is processed with a transparent avoidance inner hole, and the combination of the spherical table-shaped groove and the hemispherical groove forms a spherical cavity;

[0008] The upper plate is a rectangular plate, which is arranged horizontally. The four corners of the upper plate are respectively connected to the outer connecting sleeves of the four spoke-type sensors up and down. The universal joint includes a screw portion and a ball head portion connected up and down. The four ball socket bases and the four glands are connected one by one to form four spherical segment-shaped cavities. The ball heads of the four universal joints are rotatably arranged in the four spherical segment-shaped cavities one by one. The screw portion of the universal joint passes upward through the avoidance inner hole of the corresponding gland and is respectively connected to the inner connecting columns of the four spoke-type sensors one by one. A working gap is provided between the screw portion and the avoidance inner hole of the corresponding gland.

[0009] A junction box is provided on the upper plate, and a collection device is provided in the junction box. A threading hole is provided on the side wall of the external connection sleeve facing the junction box. The output wires of the U1 bridge, U2 bridge and U3 bridge of the spoke-type sensor pass through the threading hole and the junction box respectively, and are connected to the collection device.

[0010] The spoke sensor at the left rear corner of the upper plate is marked as sensor No. 1, the spoke sensor at the right rear corner of the upper plate is marked as sensor No. 2, the spoke sensor at the left front corner of the upper plate is marked as sensor No. 3, and the spoke sensor at the right front corner of the upper plate is marked as sensor No. 4. The center of the upper plate is set as the origin, and a coordinate system is established. The positive X-axis extends backward through the origin, the positive Z-axis extends leftward through the origin, and the positive Y-axis extends upward through the origin. The No. 1 sensor and the No. 2 sensor are symmetrical based on the X-axis, and the center distance between the No. 1 sensor and the No. 2 sensor is L. Z The third sensor and the fourth sensor are symmetrical based on the X axis, the first sensor and the third sensor are symmetrical based on the Z axis, and the center distance between the first sensor and the third sensor is L X , the second sensor and the fourth sensor are symmetrical based on the Z axis, and the calculation formula of the six-component load at the origin is as follows:

[0011] Y=Y1+Y 2+ Y 3+ Y4

[0012] X=X1+X 2+ X 3+ X4

[0013] Z=Z1+Z 2+ Z 3+ Z4

[0014] M z =(Y1+Y2-Y3-Y4)*L X / 2

[0015] M x =(Y1-Y2+Y3-Y4)*L Z / 2

[0016] M y =(-X1+X2-X3+X4)*L Z / 2+(Z1+Z2-Z3-Z4)*L X / 2

[0017] Where: Y is the longitudinal force at the origin of the upper plate, X is the lateral force at the origin of the upper plate, Z is the transverse force at the origin of the upper plate, M z is the moment about the Z axis at the origin of the upper plate, M x is the moment about the X axis at the origin of the upper plate, M yis the moment around the Y axis at the origin of the upper plate, Y1 is the longitudinal force on the No. 1 sensor, which is calculated by the pressure signal measured by the U1 bridge of the No. 1 sensor, X1 is the lateral force on the No. 1 sensor, which is calculated by the pressure signal measured by the U3 bridge of the No. 1 sensor, Z1 is the lateral force on the No. 1 sensor, which is calculated by the pressure signal measured by the U2 bridge of the No. 1 sensor, Y2 is the longitudinal force on the No. 2 sensor, which is calculated by the pressure signal measured by the U1 bridge of the No. 2 sensor, X2 is the lateral force on the No. 2 sensor, which is calculated by the pressure signal measured by the U3 bridge of the No. 2 sensor, and Z2 is the lateral force on the No. 2 sensor, which is measured by the U2 bridge of the No. 2 sensor. The variable signal is calculated, Y3 is the longitudinal force applied to the sensor No. 3, which is calculated by the pressure-variant signal measured by the U1 bridge of the sensor No. 3, X3 is the lateral force applied to the sensor No. 3, which is calculated by the pressure-variant signal measured by the U3 bridge of the sensor No. 3, Z3 is the lateral force applied to the sensor No. 3, which is calculated by the pressure-variant signal measured by the U2 bridge of the sensor No. 3, Y4 is the longitudinal force applied to the sensor No. 4, which is calculated by the pressure-variant signal measured by the U1 bridge of the sensor No. 4, X4 is the lateral force applied to the sensor No. 4, which is calculated by the pressure-variant signal measured by the U3 bridge of the sensor No. 4, and Z4 is the lateral force applied to the sensor No. 4, which is calculated by the pressure-variant signal measured by the U2 bridge of the sensor No. 4.

[0018] Furthermore, an upper cover is provided on the external connecting sleeve, and the upper cover blocks the upper end opening of the external connecting sleeve.

[0019] Furthermore, a lower cover is provided on the outer connecting sleeve, the lower cover blocks the lower end opening of the outer connecting sleeve, the lower end of the inner connecting column passes through the lower cover through the inner hole of the lower cover, and a gap is provided between the inner connecting column and the lower cover.

[0020] Furthermore, it also includes a decorative plugging cover, the four corners of the upper plate are provided with a countersunk hole group, the upper end surface of the external connecting sleeve is provided with a screw hole group, the countersunk hole group and the corresponding screw hole group of the external connecting sleeve are matched through screws, the four corners of the upper end surface of the upper plate are respectively provided with decorative countersunk grooves, the countersunk hole groups are opened on the bottom surfaces of the corresponding decorative countersunk grooves, the decorative plugging covers are adapted to the decorative countersunk grooves, and the four decorative plugging covers correspond to the four decorative countersunk grooves one by one.

[0021] Furthermore, positioning grooves are respectively provided at the four corners of the lower end surface of the upper plate, and the outer connecting sleeves of the four spoke-type sensors are matched with the stoppers of the four positioning grooves in a one-to-one correspondence.

[0022] Furthermore, a plurality of anti-slip protrusions are provided on the lower end surface of the ball socket base.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] 1. The spoke-type sensor is composed of an outer connecting sleeve, four strain beams and an inner connecting column. The present invention measures the stress of the upper plate through the micro-strain of the strain beam, thus solving the problem that the charge of the piezoelectric crystal of the force measuring platform decays over time, resulting in large errors in long-term measurements.

[0025] 2. The present invention is mainly used in the field of force measurement such as sports training, sports rehabilitation, and sports bionics. It is assembled using a spoke-type sensor with a spoke-type structure, which effectively reduces the height of the force measuring platform. The bending deformation of four strain beams is used to measure the three-component force, and the six-dimensional force load of the force measuring platform is obtained by combining and calculating the measurement values ​​of four spoke-type sensors of three-component force. The universal hinge structure of the ball and socket base and the universal hinge is used to eliminate the influence of the coupling torque generated by the internal force on the measured load when multiple spoke-type sensors are used in combination, so as to achieve accurate measurement of the six-dimensional force. At the same time, it is adaptive to the flatness of the upper plate. It has technical advantages such as small size, light weight, multiple measurement components, and high measurement accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a cross-sectional schematic diagram of the hinged connection between the spoke-type sensor and the ball-and-socket base;

[0027] Figure 2 is an axonometric view of the present invention;

[0028] Figure 3 It is an axonometric diagram of the present invention from a bottom-up perspective;

[0029] Figure 4 It is a schematic diagram of the structure of the spoke sensor;

[0030] Figure 5 is a cross-sectional view of the gland;

[0031] Figure 6 is a cross-sectional view of the ball and socket base;

[0032] Figure 7 It is a structural schematic diagram of a universal joint;

[0033] Figure 8 This is an axonometric view of the ball and socket base from an upward perspective;

[0034] Fig. 9 is a top view of the upper plate;

[0035] Fig.10 yes Fig. 9 AA section view;

[0036] Fig.11 It is a schematic diagram of the strain gauges attached to the spoke-type sensor;

[0037] Fig.12 This is the U1 bridge diagram;

[0038] Fig.13 This is the U3 bridge diagram;

[0039] Fig.14 This is the U2 bridge diagram.

[0040] In the figure, 1. upper plate, 2. spoke sensor, 3. ball socket base, 4. universal hinge, 5. pressure cover, 6. lower cover, 7. upper cover, 8. decorative plug cover, 9. junction box, 10. acquisition equipment, 11. external connection sleeve, 12. internal connection column, 13. strain beam, 14. process connection groove, 15. rectangular thin wall, 16. threading hole, 17. avoidance inner hole, 18. ball table groove, 19. stepped groove, 20. hemispherical groove, 21. screw part, 22. ball head, 23. anti-slip bump, 24. decorative groove, 25. positioning groove, 26. countersunk hole group, 31. first strain gauge, 32. second strain gauge, 33. third strain gauge, 34. fourth strain gauge, 35. fifth strain gauge, 36. 37. The sixth strain gauge, 38. The seventh strain gauge, 39. The ninth strain gauge, 310. The tenth strain gauge, 311. The eleventh strain gauge, 312. The twelfth strain gauge. DETAILED DESCRIPTION

[0041] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is described below by the specific embodiments shown in the accompanying drawings. However, it should be understood that these descriptions are only exemplary and are not intended to limit the scope of the present invention. In addition, in the following description, the description of well-known structures and technologies is omitted to avoid unnecessary confusion of the concept of the present invention.

[0042] The connection mentioned in the present invention is divided into fixed connection and detachable connection. The fixed connection is a non-detachable connection including but not limited to conventional fixed connection methods such as folding connection, rivet connection, bonding connection and welding connection. The detachable connection includes but not limited to conventional detachable methods such as bolt connection, snap connection, pin connection and hinge connection. When the specific connection method is not clearly defined, it is assumed that at least one connection method can be found in the existing connection methods to achieve the function, and those skilled in the art can choose according to their needs. For example: welding connection is selected for fixed connection, and bolt connection is selected for detachable connection.

[0043] The present invention will be further described in detail below in conjunction with the accompanying drawings. The following embodiments are provided to explain the present invention, but the present invention is not limited to the following embodiments.

[0044] Example: Figure 1 to Figure 14 As shown, a six-component portable force measurement platform suitable for the field of sports rehabilitation includes an upper plate 1, a junction box 9, a spoke sensor 2, a universal hinge 4, a pressure cover 5 and a ball and socket base 3;

[0045] The spoke-type sensor 2 includes an inner connecting column 12 and an outer connecting sleeve 11 which are coaxially arranged inside and outside. Four process connecting grooves 14 which penetrate from top to bottom are evenly arranged on the circumference of the inner wall of the outer connecting sleeve 11. Four rectangular thin walls 15 are arranged in the four process connecting grooves 14 in a one-to-one correspondence. The two sides of the rectangular thin wall 15 are respectively connected to the two side walls of the process connecting groove 14. A gap is provided between the rectangular thin wall 15 and the bottom surface of the corresponding process connecting groove 14. The rectangular thin wall 15 is parallel to the bottom surface of the corresponding process connecting groove 14. The inner connecting column 12 is connected to the rectangular thin wall 15 through a strain beam 13. The strain beam 13 is perpendicular to the corresponding rectangular thin wall 15. The axis of the strain beam 13 passes through the center of the corresponding rectangular thin wall 15. The strain beam 13 is perpendicular to the inner connecting column 12. The axis of the strain beam 13 intersects the axis of the inner connecting column 12 at right angles.

[0046] The strain beam 13 is a rectangular column beam, and the four strain beams 13 are respectively located on the left side, right side, front side and rear side of the inner connecting column 12. The first strain gauge 31 is pasted on the upper side of the strain beam 13 on the rear side, the third strain gauge 33 is pasted on the lower side, the ninth strain gauge 39 is pasted on the left side, and the twelfth strain gauge 312 is pasted on the right side. The second strain gauge 32 is pasted on the upper side of the strain beam 13 on the front side, the fourth strain gauge 34 is pasted on the lower side, the tenth strain gauge 310 is pasted on the left side, and the eleventh strain gauge 311 is pasted on the right side. The fifth strain gauge 35 is pasted on the rear side of the strain beam 13 on the left side, the third strain gauge 33 is pasted on the lower side, the ninth strain gauge 39 is pasted on the left side, and the twelfth strain gauge 312 is pasted on the right side. The seventh strain gauge 37 is pasted on the side surface, the sixth strain gauge 36 is pasted on the rear side surface of the right strain beam 13, and the eighth strain gauge 38 is pasted on the front side surface. The first strain gauge 31, the third strain gauge 33, the second strain gauge 32 and the fourth strain gauge 34 are electrically connected in sequence to form a Wheatstone bridge, which is marked as U1. The fifth strain gauge 35, the seventh strain gauge 37, the sixth strain gauge 36 and the eighth strain gauge 38 are electrically connected in sequence to form a Wheatstone bridge, which is marked as U3. The ninth strain gauge 39, the eleventh strain gauge 311, the tenth strain gauge 310 and the twelfth strain gauge 312 are electrically connected in sequence to form a Wheatstone bridge, which is marked as U2.

[0047] A stepped groove 19 is provided on the upper end surface of the ball socket base 3, a hemispherical groove 20 is provided on the bottom surface of the stepped groove 19, the pressure cover 5 is adapted to the stepped groove 19, a spherical table-shaped groove 18 is provided on the lower end surface of the pressure cover 5, a transparent avoidance inner hole 17 is processed on the top surface of the spherical table-shaped groove 18, the radii of the spherical table-shaped groove 18 and the hemispherical groove 20 are equal, the spherical table-shaped groove 18 and the hemispherical groove 20 are combined to form a spherical cavity, and a flange flange is provided at the lower end of the ball socket base 3, and the flange flange is used to fix the ball socket base 3;

[0048] The upper plate 1 is a rectangular plate, which is arranged horizontally. The four corners of the upper plate 1 are respectively connected to the outer connecting sleeves 11 of the four spoke-type sensors 2 up and down. The universal hinge 4 includes a screw portion 21 and a ball head portion 22 connected up and down. The four ball socket bases 3 and the four pressure covers 5 are connected one by one to form four spherical cavity cavities. The ball heads 22 of the four universal hinges 4 are rotatably arranged in the four spherical cavity cavities one by one. The screw portion 21 of the universal hinge 4 passes upward through the avoidance inner hole 17 of the corresponding pressure cover 5, and is respectively connected to the inner connecting columns 12 of the four spoke-type sensors 2 one by one. A working gap is provided between the screw portion 21 and the avoidance inner hole 17 of the corresponding pressure cover 5; the axis of the inner connecting column 12 has a threaded hole for connecting to the screw portion 21 of the universal hinge 4.

[0049] A junction box 9 is provided on the upper plate 1, and a collection device 10 is provided inside the junction box 9. A threading hole 16 is provided on the side wall of the external connection sleeve 11 facing the junction box 9. The output wires of the U1 bridge, U2 bridge and U3 bridge of the spoke-type sensor 2 pass through the threading hole 16 and the junction box 9 respectively, and are connected to the collection device 10.

[0050] The spoke sensor 2 located at the left rear corner of the upper plate 1 is marked as sensor No. 1, the spoke sensor 2 located at the right rear corner of the upper plate 1 is marked as sensor No. 2, the spoke sensor 2 located at the left front corner of the upper plate 1 is marked as sensor No. 3, and the spoke sensor 2 located at the right front corner of the upper plate 1 is marked as sensor No. 4. The center of the upper plate 1 is set as the origin, and a coordinate system is established. The positive X-axis extends backward through the origin, the positive Z-axis extends leftward through the origin, and the positive Y-axis extends upward through the origin. The No. 1 sensor and the No. 2 sensor are symmetrical based on the X-axis, and the center distance between the No. 1 sensor and the No. 2 sensor is L. Z The third sensor and the fourth sensor are symmetrical based on the X axis, the first sensor and the third sensor are symmetrical based on the Z axis, and the center distance between the first sensor and the third sensor is L X , the second sensor and the fourth sensor are symmetrical based on the Z axis, and the calculation formula of the six-component load at the origin is as follows:

[0051] Y=Y1+Y 2+ Y 3+ Y4

[0052] X=X1+X 2+ X 3+ X4

[0053] Z=Z1+Z 2+ Z 3+ Z4

[0054] M z =(Y1+Y2-Y3-Y4)*L X / 2

[0055] M x =(Y1-Y2+Y3-Y4)*L Z / 2

[0056] M y =(-X1+X2-X3+X4)*L Z / 2+(Z1+Z2-Z3-Z4)*L X / 2

[0057] Where: Y is the longitudinal force at the origin of the upper plate 1, X is the lateral force at the origin of the upper plate 1, Z is the transverse force at the origin of the upper plate 1, M z is the moment about the Z axis at the origin of the upper plate 1, M x is the moment about the X axis at the origin of the upper plate 1, M y is the moment around the Y axis at the origin of the upper plate 1, Y1 is the longitudinal force on the No. 1 sensor, which is calculated by the pressure-variant signal measured by the U1 bridge of the No. 1 sensor, X1 is the lateral force on the No. 1 sensor, which is calculated by the pressure-variant signal measured by the U3 bridge of the No. 1 sensor, Z1 is the lateral force on the No. 1 sensor, which is calculated by the pressure-variant signal measured by the U2 bridge of the No. 1 sensor, Y2 is the longitudinal force on the No. 2 sensor, which is calculated by the pressure-variant signal measured by the U1 bridge of the No. 2 sensor, X2 is the lateral force on the No. 2 sensor, which is calculated by the pressure-variant signal measured by the U3 bridge of the No. 2 sensor, and Z2 is the lateral force on the No. 2 sensor, which is measured by the U2 bridge of the No. 2 sensor. The pressure-variant signal is calculated, Y3 is the longitudinal force applied to the sensor No. 3, which is calculated by the pressure-variant signal measured by the U1 bridge of the sensor No. 3, X3 is the lateral force applied to the sensor No. 3, which is calculated by the pressure-variant signal measured by the U3 bridge of the sensor No. 3, Z3 is the lateral force applied to the sensor No. 3, which is calculated by the pressure-variant signal measured by the U2 bridge of the sensor No. 3, Y4 is the longitudinal force applied to the sensor No. 4, which is calculated by the pressure-variant signal measured by the U1 bridge of the sensor No. 4, X4 is the lateral force applied to the sensor No. 4, which is calculated by the pressure-variant signal measured by the U3 bridge of the sensor No. 4, and Z4 is the lateral force applied to the sensor No. 4, which is calculated by the pressure-variant signal measured by the U2 bridge of the sensor No. 4.

[0058] An upper cover 7 is provided on the outer connecting sleeve 11 , and the upper cover 7 blocks the upper end opening of the outer connecting sleeve 11 to protect the spoke-type sensor 2 .

[0059] A lower cover 6 is provided on the outer connecting sleeve 11, and the lower cover 6 blocks the lower end opening of the outer connecting sleeve 11. The lower end of the inner connecting column 12 passes through the lower cover 6 through the inner hole of the lower cover 6. A gap is provided between the inner connecting column 12 and the lower cover 6. The lower cover 6 is used to protect the spoke-type sensor 2.

[0060] It also includes a decorative plugging cover 8. Countersunk hole groups 26 are provided at the four corners of the upper plate 1. A screw hole group is provided on the upper end surface of the external connecting sleeve 11. The countersunk hole group 26 is matched with the corresponding screw hole group of the external connecting sleeve 11 through screws. Decorative countersunk grooves 24 are respectively provided at the four corners of the upper end surface of the upper plate 1. The countersunk hole groups 26 are opened on the bottom surfaces of the corresponding decorative countersunk grooves 24. The decorative plugging cover 8 is adapted to the decorative countersunk grooves 24. The four decorative plugging covers 8 correspond to the four decorative countersunk grooves 24 one by one. The decorative plugging cover 8 is used to cover the countersunk hole group 26 and level the decorative countersunk grooves 24 of the upper plate 1 to ensure the flatness and beauty of the upper plate 1.

[0061] The four corners of the lower end surface of the upper plate 1 are respectively provided with positioning recesses 25 , and the outer connecting sleeves 11 of the four spoke-type sensors 2 are matched with the four positioning recesses 25 in a one-to-one corresponding manner to ensure the accurate positioning of the spoke-type sensors 2 .

[0062] A plurality of anti-skid protrusions 23 are provided on the lower end surface of the ball socket base 3 to prevent the ball socket base 3 from skidding.

[0063] The spoke-type sensor 2 is composed of an external connecting sleeve 11, four strain beams 13 and an internal connecting column 12. The present invention measures the stress of the upper plate 1 through the micro-strain of the strain beam 13, thereby solving the problem that the charge of the piezoelectric crystal of the force measuring platform decays over time, resulting in large errors in long-term measurements.

[0064] The outer connecting sleeve 11 has the screw hole group uniformly distributed, which is used to connect with the upper plate 1. The outer end of the strain beam 13 is vertically connected to the rectangular thin wall 15. The structure of the rectangular thin wall 15 can change the deformation form of the strain beam 13 under the force condition, improve the deformation output of the force, and thus improve the measurement accuracy. If there is no rectangular thin wall 15 structure, the four strain beams 13 will produce S-shaped deformation under the action of the longitudinal force, and will produce tensile and compressive deformation under the action of the transverse force and the lateral force. When there is a rectangular thin wall 15 structure, the four strain beams 13 will produce bending deformation under the action of the longitudinal force, and will also produce bending deformation under the action of the transverse force and the lateral force. It can be known from the knowledge of mechanics that the deformation of bending deformation is much larger than that of tensile deformation under similar mechanical conditions. Strain gauges are pasted on the four strain beams 13 and form an electric bridge to measure the longitudinal, transverse and lateral forces. The obtained pressure change signal is larger and the measurement result is more accurate. The present invention is mainly used in the field of force measurement such as sports training, sports rehabilitation, and sports bionics. It is assembled using a spoke-type sensor 2 with a spoke-type structure, which effectively reduces the height of the force measuring platform. The bending deformation of four strain beams 13 is used to measure the three-component force, and the six-dimensional force load of the force measuring platform is obtained by combining and calculating the measurement values ​​of four three-component force spoke-type sensors 2. The universal hinge structure of the ball socket base 3 and the universal hinge 4 eliminates the influence of the coupling torque generated by the internal force on the measured load when multiple spoke-type sensors 2 are used in combination, thereby realizing accurate measurement of the six-dimensional force. At the same time, it is adaptive to the flatness of the upper plate. It has technical advantages such as small size, light weight, multiple measurement components, and high measurement accuracy.

[0065] The above embodiments are merely exemplary descriptions of the present invention and do not limit its protection scope. Those skilled in the art may also make partial changes thereto, which are within the protection scope of the present invention as long as they do not exceed the spirit of the present invention.

Claims

1. A six-component portable force measurement platform suitable for use in the field of sports rehabilitation, characterized in that: It comprises an upper plate (1), a junction box (9), a spoke-type sensor (2), a universal joint (4), a pressure cover (5) and a ball and socket base (3); The spoke-type sensor (2) comprises an inner connecting column (12) and an outer connecting sleeve (11) which are coaxially arranged inside and outside. Four process connecting grooves (14) which penetrate from top to bottom are evenly arranged on the circumference of the inner wall of the outer connecting sleeve (11). Four rectangular thin walls (15) are arranged in the four process connecting grooves (14) in a one-to-one correspondence. The two sides of the rectangular thin walls (15) are respectively connected to the two side walls of the process connecting grooves (14). The rectangular thin walls (15) are parallel to the bottom surface of the corresponding process connecting grooves (14). The inner connecting column (12) and the rectangular thin walls (15) are connected via a strain beam (13). The strain beam (13) is perpendicular to the corresponding rectangular thin wall (15), and the strain beam (13) is perpendicular to the inner connecting column (12). The strain beam (13) is a rectangular column beam. The four strain beams (13) are respectively located on the left side, right side, front side and rear side of the inner connecting column (12). The strain beam (13) located on the rear side has a first strain gauge (31) attached to its upper side, a third strain gauge (33) attached to its lower side, a ninth strain gauge (39) attached to its left side, and a twelfth strain gauge (312) attached to its right side. The strain beam (13) located on the front side has a second strain gauge (32) attached to its upper side, a fourth strain gauge (34) attached to its lower side, a tenth strain gauge (310) attached to its left side, and an eleventh strain gauge (311) attached to its right side. The strain beam (13) located on the left side has a fifth strain gauge (35) attached to its rear side, and the front side has a fifth strain gauge (36) attached to its A seventh strain gauge (37) is attached to the surface, a sixth strain gauge (36) is attached to the rear side of the right strain beam (13), and an eighth strain gauge (38) is attached to the front side. The first strain gauge (31), the third strain gauge (33), the second strain gauge (32) and the fourth strain gauge (34) are electrically connected in sequence to form a Wheatstone bridge, which is marked as U1. The fifth strain gauge (35), the seventh strain gauge (37), the sixth strain gauge (36) and the eighth strain gauge (38) are electrically connected in sequence to form a Wheatstone bridge, which is marked as U3. The ninth strain gauge (39), the eleventh strain gauge (311), the tenth strain gauge (310) and the twelfth strain gauge (312) are electrically connected in sequence to form a Wheatstone bridge, which is marked as U2. The upper end surface of the ball socket base (3) is provided with a stepped groove (19), the bottom surface of the stepped groove (19) is provided with a hemispherical groove (20), the pressure cover (5) is matched with the stepped groove (19), the lower end surface of the pressure cover (5) is provided with a spherical table-shaped groove (18), the top surface of the spherical table-shaped groove (18) is processed with a transparent avoidance inner hole (17), and the spherical table-shaped groove (18) and the hemispherical groove (20) are combined to form a spherical cavity; The upper plate (1) is a rectangular plate. The upper plate (1) is arranged horizontally. The four corners of the upper plate (1) are respectively connected to the outer connecting sleeves (11) of the four spoke-type sensors (2) in upper and lower directions. The universal joint (4) comprises a screw portion (21) and a ball head portion (22) connected to each other in upper and lower directions. The four ball socket bases (3) and the four glands (5) are connected in a one-to-one correspondence to form four spherical segment-shaped cavities. The ball heads (22) of the four universal joints (4) are rotatably arranged in the four spherical segment-shaped cavities in a one-to-one correspondence. The screw portion (21) of the universal joint (4) passes upward through the avoidance inner hole (17) of the corresponding gland (5) and is respectively connected to the inner connecting columns (12) of the four spoke-type sensors (2) in a one-to-one correspondence. A working gap is provided between the screw portion (21) and the avoidance inner hole (17) of the corresponding gland (5). A junction box (9) is provided on the upper plate (1), a collection device (10) is provided in the junction box (9), a wire threading hole (16) is provided on a side wall of the external connection sleeve (11) facing the junction box (9), and output wires of the U1 bridge, U2 bridge and U3 bridge of the spoke-type sensor (2) pass through the wire threading hole (16) and the junction box (9) respectively, and are connected to the collection device (10); The spoke sensor (2) located at the left rear corner of the upper plate (1) is marked as sensor No. 1, the spoke sensor (2) located at the right rear corner of the upper plate (1) is marked as sensor No. 2, the spoke sensor (2) located at the left front corner of the upper plate (1) is marked as sensor No. 3, and the spoke sensor (2) located at the right front corner of the upper plate (1) is marked as sensor No.

4. The center of the upper plate (1) is set as the origin, and a coordinate system is established. The positive X-axis extends backward through the origin, the positive Z-axis extends leftward through the origin, and the positive Y-axis extends upward through the origin. The sensor No. 1 and the sensor No. 2 are symmetrical based on the X-axis. The center distance between the sensor No. 1 and the sensor No. 2 is L. Z The third sensor and the fourth sensor are symmetrical based on the X axis, the first sensor and the third sensor are symmetrical based on the Z axis, and the center distance between the first sensor and the third sensor is L X , the second sensor and the fourth sensor are symmetrical based on the Z axis, and the calculation formula of the six-component load at the origin is as follows: Y=Y1+Y 2+ AND 3+ Y4 X=X1+X 2+ X 3+ X4 Z=Z1+Z 2+ WITH 3+ Z4 M z =(Y1+Y2-Y3-Y4)*L X / 2 M x =(Y1-Y2+Y3-Y4)*L Z / 2 M y =(-X1+X2-X3+X4)*L Z / 2+(Z1+Z2-Z3-Z4)*L X / 2 Where: Y is the longitudinal force at the origin of the upper plate (1), X is the lateral force at the origin of the upper plate (1), Z is the transverse force at the origin of the upper plate (1), and M is z is the moment about the Z axis at the origin of the upper plate (1), M x is the moment about the X-axis at the origin of the upper plate (1), M y is the moment about the Y axis at the origin of the upper plate (1), Y1 is the longitudinal force on the No. 1 sensor, calculated by the pressure signal measured by the U1 bridge of the No. 1 sensor, X1 is the lateral force on the No. 1 sensor, calculated by the pressure signal measured by the U3 bridge of the No. 1 sensor, Z1 is the lateral force on the No. 1 sensor, calculated by the pressure signal measured by the U2 bridge of the No. 1 sensor, Y2 is the longitudinal force on the No. 2 sensor, calculated by the pressure signal measured by the U1 bridge of the No. 2 sensor, X2 is the lateral force on the No. 2 sensor, calculated by the pressure signal measured by the U3 bridge of the No. 2 sensor, and Z2 is the lateral force on the No. 2 sensor, measured by the U2 bridge of the No. 2 sensor. The pressure-variant signal is calculated, Y3 is the longitudinal force applied to the sensor No. 3, and is calculated by the pressure-variant signal measured by the U1 bridge of the sensor No.

3. X3 is the lateral force applied to the sensor No. 3, and is calculated by the pressure-variant signal measured by the U3 bridge of the sensor No.

3. Z3 is the lateral force applied to the sensor No. 3, and is calculated by the pressure-variant signal measured by the U2 bridge of the sensor No.

3. Y4 is the longitudinal force applied to the sensor No. 4, and is calculated by the pressure-variant signal measured by the U1 bridge of the sensor No.

4. X4 is the lateral force applied to the sensor No. 4, and is calculated by the pressure-variant signal measured by the U3 bridge of the sensor No.

4. Z4 is the lateral force applied to the sensor No. 4, and is calculated by the pressure-variant signal measured by the U2 bridge of the sensor No.

4.

2. A six-component portable force measurement platform suitable for the field of sports rehabilitation according to claim 1, characterized in that: An upper cover (7) is provided on the outer connecting sleeve (11), and the upper cover (7) blocks the upper end opening of the outer connecting sleeve (11).

3. A six-component portable force measurement platform suitable for the field of sports rehabilitation according to claim 2, characterized in that: The outer connecting sleeve (11) is provided with a lower cover (6), the lower cover (6) blocks the lower end opening of the outer connecting sleeve (11), the lower end of the inner connecting column (12) passes through the lower cover (6) through the inner hole of the lower cover (6), and a gap is provided between the inner connecting column (12) and the lower cover (6).

4. A six-component portable force measurement platform suitable for the field of sports rehabilitation according to claim 1, characterized in that: It also includes a decorative plugging cover (8), four corners of the upper plate (1) are provided with a countersunk hole group (26), the upper end surface of the external connection sleeve (11) is provided with a screw hole group, the countersunk hole group (26) and the corresponding screw hole group of the external connection sleeve (11) are matched by screws, the four corners of the upper end surface of the upper plate (1) are respectively provided with a decorative sink groove (24), the countersunk hole group (26) is opened on the bottom surface of the corresponding decorative sink groove (24), the decorative plugging cover (8) is adapted to the decorative sink groove (24), and the four decorative plugging covers (8) are matched with the four decorative sink grooves (24) in a one-to-one correspondence.

5. A six-component portable force measurement platform suitable for the field of sports rehabilitation according to claim 2, characterized in that: Four corners of the lower end surface of the upper plate (1) are respectively provided with positioning recessed grooves (25), and the outer connecting sleeves (11) of the four spoke-type sensors (2) are matched with the four positioning recessed grooves (25) in a one-to-one corresponding manner.

6. A six-component portable force measurement platform suitable for the field of sports rehabilitation according to any one of claims 1 to 5, characterized in that: A plurality of anti-slip convex points (23) are provided on the lower end surface of the ball socket base (3).

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