CN114252181B - Counter force measuring method and device, stress sensor assembly and engineering machinery - Google Patents

Abstract

The embodiment of the invention provides a counter force measuring method and device, a stress sensor assembly and engineering machinery, and belongs to the field of engineering machinery. The device comprises: the included angle measuring module is used for acquiring an included angle between the resultant force of the contact load and the central axis and an included angle between a plane formed by the resultant force of the contact load and the central axis and a plane formed by the central axis and the installation position of a strain gauge; the inclination angle detection device is used for detecting the inclination angles of an X axis, a Y axis and a Z axis in the coordinate system with the gravity direction respectively; and the controller is used for obtaining counter force according to the contact load resultant force, the included angle between the contact load resultant force and the central axis, the included angle between the plane formed by the contact load resultant force and the central axis and the plane formed by the central axis and the installation position of the strain gauge, and the included angles between the X axis, the Y axis and the Z axis in the coordinate system and the gravity direction respectively. The influence of the lateral load formed by deflection deformation, base plate inclination and the like of the stress sensor assembly on the counter force measurement can be effectively eliminated, and the counter force measurement precision is improved.

Description

Counter force measuring method and device, stress sensor assembly and engineering machinery

Technical Field

The invention relates to the field of engineering machinery, in particular to a counter force measuring method and device, a stress sensor assembly and engineering machinery.

Background

In mechanical construction, a counter force measurement is usually necessary. For example, in a construction machine, it is necessary to measure a leg reaction force.

In order to improve the anti-overturning capability of engineering machinery (such as an automobile crane, a pump truck, a fire truck and the like) during operation, a supporting leg supporting structure generally extends to the periphery, and the supporting force of the supporting structure directly reflects the current supporting safety condition of the engineering truck, for example: (1) When the counter force of any supporting leg is larger than the designed bearing limit of the supporting leg, the supporting leg has the risk of instability and failure, and the whole machine has the possibility of rollover accidents; (2) When the counter force of any supporting leg is close to the bearing capacity of the ground, the supporting ground has a collapse and settlement risk, and the engineering machinery can be tipped over; (3) When the counter force of any supporting leg is close to zero, the supporting leg is indicated to generate a 'virtual leg', and construction potential safety hazards exist; (4) More seriously, when the counter force of any two adjacent supporting legs is close to zero, the engineering machinery has serious risk of rollover and instability. It is therefore important to accurately measure the reaction force of the legs of the construction machine.

Disclosure of Invention

The embodiment of the invention aims to provide a counter force measuring method, a counter force measuring device, a stress sensor assembly and engineering machinery, which can accurately measure counter force.

In order to achieve the above object, an embodiment of the present invention provides a reaction force measuring device including: the included angle measuring module is used for acquiring an included angle between a resultant force of a contact load borne by the stress sensor assembly and a central axis of the stress sensor assembly, and acquiring an included angle between a plane formed by the resultant force of the contact load and the central axis and a plane formed by the central axis and an installation position of a strain gauge in a strain sensitive area of the stress sensor assembly; the inclination angle detection device is used for detecting the inclination angles of an X axis, a Y axis and a Z axis in a three-dimensional Cartesian coordinate system with the gravity direction respectively, wherein the Z axis in the three-dimensional Cartesian coordinate system is the central axis of the stress sensor assembly, and the X axis points to the installation position of the strain gauge; and the controller is used for obtaining the counter force born by the stress sensor assembly according to the contact load resultant force, the included angle between the contact load resultant force and the central axis, the included angle between the plane formed by the contact load resultant force and the central axis and the plane formed by the central axis and the installation position of a strain gauge, and the included angles between the X axis, the Y axis and the Z axis in the three-dimensional Cartesian coordinate system and the gravity direction.

Optionally, the angle measurement module includes a second set of strain gauge pairs within the strain sensitive region, wherein the second set of strain gauges includes 4 strain gauge pairs arranged circumferentially and symmetrically at a second height of the strain sensitive region of the force sensor assembly, wherein each strain gauge pair includes a transversely arranged strain gauge and a longitudinally arranged strain gauge such that it is configured to be mounted in a T-shape or an inverted T-shape.

Optionally, the included angle measuring module is a second bridge circuit, wherein in the second bridge circuit: forming a first arm from a laterally disposed strain gage of a first strain gage pair and a longitudinally disposed strain gage of a third strain gage pair, forming a second arm from a longitudinally disposed strain gage of the first strain gage pair and a laterally disposed strain gage of the third strain gage pair, wherein the first arm and the second arm form a first half bridge of the second bridge circuit, wherein the first strain gage pair and the third strain gage pair are symmetrically disposed; the third arm is composed of a transversely arranged strain gage of a second strain gage pair and a longitudinally arranged strain gage of a fourth strain gage pair, the fourth arm is composed of a longitudinally arranged strain gage of the second strain gage pair and a transversely arranged strain gage of the fourth strain gage pair, the third arm and the fourth arm form a second half bridge of the second bridge circuit, the second strain gage pair and the fourth strain gage pair are symmetrically arranged, and one or more pairs of fixed resistors connected together in series are connected in parallel in the second bridge circuit.

Optionally, the device further comprises a first bridge circuit, the first bridge circuit consisting of 4 pairs of strain gauges arranged circumferentially symmetrically at a first height of the strain sensitive area; and the processor is further used for obtaining the resultant force of the contact load according to the output voltage of the first bridge circuit and the included angle between the resultant force of the contact load and the central axis.

Optionally, the force sensor assembly includes: the upper surface of the bearing area is used for bearing the load applied by the structure to be tested; a fixed region for mechanical connection with a structure under test, wherein the fixed region is disposed around the load-bearing region; the strain sensitive area is positioned below the fixed area and is provided with a cavity; and a support region below the strain sensitive region for supporting.

Optionally, the included angle measuring module is located on the inner wall of the cavity of the strain sensitive area; and the tilt angle detection device is located in the support area, preferably in the bottom center of the support area.

Accordingly, an embodiment of the present invention further provides a reaction force measuring device, including: the first bridge circuit consists of a first group of strain gauges arranged in a strain sensitive area of the supporting leg stress sensor assembly; the second bridge circuit is arranged for acquiring an included angle between a resultant force of a contact load borne by a stress sensor assembly and a central axis of the stress sensor assembly, and acquiring an included angle between a plane formed by the resultant force of the contact load and the central axis and a plane formed by the central axis and an installation position of a strain gauge in the strain sensitive area of the stress sensor assembly; and the inclination angle detection device is arranged at the bottom of the strain sensitive area and is used for detecting included angles between an X axis, a Y axis and a Z axis in a three-dimensional Cartesian coordinate system and the gravity direction respectively, wherein the Z axis in the three-dimensional Cartesian coordinate system is the central axis, and the X axis points to the installation position of a strain gauge.

Correspondingly, an embodiment of the present invention further provides a counter force measuring method, where the method is used for the above-mentioned counter force measuring device, and the method includes: acquiring an included angle between resultant force of contact load borne by a stress sensor assembly and a central axis of the stress sensor assembly, and acquiring an included angle between a plane formed by the resultant force of the contact load and the central axis and a plane formed by the central axis and a mounting position of a strain gauge in a strain sensitive area of the stress sensor assembly; detecting inclination angles of an X axis, a Y axis and a Z axis in a three-dimensional Cartesian coordinate system with the gravity direction respectively, wherein the Z axis in the three-dimensional Cartesian coordinate system is a central axis of the stress sensor assembly, and the X axis points to the installation position of the strain gauge; and obtaining the counter force born by the stress sensor assembly according to the contact load resultant force, the included angle between the contact load resultant force and the central axis, the included angle between the plane formed by the contact load resultant force and the central axis and the plane formed by the central axis and the installation position of a strain gauge, and the included angles between the X axis, the Y axis and the Z axis in the three-dimensional Cartesian coordinate system and the gravity direction respectively.

Optionally, the method further includes: and obtaining the resultant force of the contact load according to the output voltage of the first bridge circuit and the included angle between the resultant force of the contact load and the central axis.

Optionally, obtaining the contact load resultant force and the included angle of the central axis, obtaining the contact load resultant force borne by the force-receiving sensor assembly and the included angle between the plane formed by the central axis and the plane formed by the mounting position of a strain gauge in the strain sensitive area of the central axis and the force-receiving sensor assembly includes: acquiring an included angle between the resultant force of the contact load and the central axis, and an included angle between a plane formed by the resultant force of the contact load borne by the stress sensor assembly and the central axis and a plane formed by the central axis and the mounting position of a strain gauge in a strain sensitive area of the stress sensor assembly according to the following formulas:

wherein the content of the first and second substances,

wherein, U _i Is the input voltage of the second bridge circuit, K is the sensitivity coefficient of the strain gauge, v is the Poisson's ratio of the material of the force sensor component, E is the elastic modulus of the material of the force sensor component, r ₁ Is the inner radius of the strain sensitive region, r ₂ Is the outer radius of the strain sensitive area, alpha is the included angle between the resultant force of the contact load and the central axis, U _x1 Is a first half-bridge voltage, U, of said second bridge circuit _x2 For the second half-bridge voltage of the second bridge circuit, θ is the contact load resultant force and the included angle between the plane formed by the central axis and the plane formed by the mounting positions of the central axis and the strain gauge, β is the circumferential included angle between each strain gauge of the first group of strain gauges and each strain gauge of the second group of strain gauges, h ₁ Is the perpendicular distance, gamma, from the equivalent spherical center of the support area of the force sensor assembly to the mounting position of the second set of strain gauges _x 、γ _y 、γ _z The included angles of the X axis, the Y axis and the Z axis with the gravity direction are respectively.

Correspondingly, an embodiment of the present invention further provides a reaction force measuring method, where the reaction force measuring device described above includes: acquiring the output voltage of a first bridge circuit; acquiring a first half-bridge voltage and a second half-bridge voltage which are respectively output by two half-bridges of a second bridge circuit; acquiring included angles between an X axis, a Y axis and a Z axis in a three-dimensional Cartesian coordinate system detected by an inclination angle detection device and the gravity direction respectively; and calculating the reaction force according to the output voltage of the first bridge circuit, the first half-bridge voltage, the second half-bridge voltage and the included angles of the X axis, the Y axis and the Z axis with the gravity direction respectively.

Optionally, calculating the reaction force according to the output voltage of the first bridge circuit, the first half-bridge voltage, the second half-bridge voltage, and the included angles between the X axis, the Y axis, and the Z axis and the gravity direction respectively includes: the counter force is calculated using a function obtained in advance for calculating the counter force.

Optionally, the function for calculating the counter force is pre-calculated by:

from the first bridge circuit, the following equation is derived:

from the second bridge circuit, the following equation is derived:

wherein the content of the first and second substances,

the following equation is obtained from the relationship between the reaction force and the resultant contact load force:

F _G ＝F×(cosαcosγ _z +sinαcosθcosγ _x +sinαsinθcosγ _y )；

a function for calculating the reaction force is obtained from the above equations,

wherein, U _o Is the output voltage of the first bridge circuit, U _i Is the input voltage of the first bridge circuit and the second bridge circuit, K is the sensitivity coefficient of a strain gauge, v is the Poisson's ratio of the material of the force-bearing sensor component, E is the elastic modulus of the material of the force-bearing sensor component, F is the resultant force of the contact load, r is ₁ Is the inner radius of the strain sensitive area, r ₂ Is the outer radius of the strain sensitive area, alpha is the included angle between the resultant force of the contact load and the central axis, U _x1 Is said first half-bridge voltage, U _x2 For the second half-bridge voltage, theta is the contact load resultant force and the included angle between the plane formed by the central axis and the plane formed by the mounting positions of the central axis and the strain gauges, beta is the hoop included angle between each strain gauge of the first group of strain gauges and each strain gauge of the second group of strain gauges, h ₁ Is the perpendicular distance, gamma, from the equivalent spherical center of the support area of the force sensor assembly to the mounting position of the second set of strain gauges _x 、γ _y 、γ _z Respectively, the included angles between the X axis, the Y axis and the Z axis and the gravity direction, F _G Is the counter force.

Optionally, the function for calculating the reaction force is obtained in advance using a neural network algorithm according to the following formula fit:

wherein, F _G Is the counter force, f _g () For calculating the function of the counter-force, U _o Is the output voltage of the first bridge circuit, U _i Is the output voltage of the first bridge circuit and the second bridge circuit, U _x1 Is said first half-bridge voltage, U _x2 Is the second half-bridge voltage, γ _x 、γ _y 、γ _z The included angles of the X axis, the Y axis and the Z axis with the gravity direction are respectively.

Correspondingly, the embodiment of the invention provides a stress sensor assembly, and the stress sensor assembly is provided with the counter force measuring device.

Correspondingly, the embodiment of the invention provides a construction machine, and the construction machine is provided with the counter force measuring device or the stress sensor assembly.

Accordingly, embodiments of the present invention provide a machine-readable storage medium having stored thereon instructions for causing a machine to perform the method of counterforce measurement described above.

According to the technical scheme, the counter force borne by the stress sensor assembly is obtained by using the included angle between the resultant force of the contact load and the central axis, the included angle between the plane formed by the resultant force of the contact load and the central axis and the plane formed by the central axis and the installation position of the strain gauge, and the included angles between the X axis, the Y axis and the Z axis in the three-dimensional Cartesian coordinate system and the gravity direction, so that the influence of the lateral load borne by the stress sensor assembly due to deflection deformation on counter force measurement can be effectively eliminated, and the counter force measurement precision is improved.

Additional features and advantages of embodiments of the invention will be set forth in the detailed description which follows.

Drawings

The accompanying drawings, which are included to provide a further understanding of the embodiments of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the embodiments of the invention and not to limit the embodiments of the invention. In the drawings:

FIG. 1 illustrates a schematic view of the installation of a force sensor assembly as a leg reaction sensor assembly according to an embodiment of the invention;

FIG. 2 is a schematic diagram showing the structure and installation of a force-receiving sensor assembly as a leg reaction force sensor assembly according to an embodiment of the invention;

fig. 3 (a) shows a plan view of the leg reaction force sensor assembly shown in fig. 2, and fig. 3 (b) shows a perspective view of the leg reaction force sensor assembly shown in fig. 2;

FIG. 4 shows a cross-sectional view of the leg reaction force sensor assembly shown in FIG. 2;

FIG. 5 illustrates the blocking effect of the annular groove on the distributed transmission of the foot support plate contact force;

FIG. 6 shows a dimensional schematic of the annular groove;

FIG. 7 shows a schematic diagram of a bridge circuit formed by strain gauges;

FIG. 8 shows a leg reaction load path transfer diagram;

FIG. 9 is a schematic diagram illustrating the construction and installation of a force sensor assembly as a leg reaction force sensor assembly according to one embodiment of the invention;

FIGS. 10 (a) to 10 (c) show a top view, a side view, and a perspective view, respectively, of the force sensor assembly shown in FIG. 9 as a leg reaction force sensor assembly;

FIG. 11 shows a cross-sectional view of the leg reaction force sensor assembly shown in FIG. 9;

FIG. 12 shows a schematic inclination of the leg reaction force sensor assembly;

FIG. 13 is a block diagram showing the structure of a reaction force measuring device according to an embodiment of the invention;

FIG. 14 shows a schematic diagram of a second bridge circuit;

FIG. 15 shows a schematic diagram of a first bridge circuit;

FIG. 16 shows a schematic view of the angle between the first and second sets of strain gages;

FIG. 17 is a schematic diagram showing some parameters involved in the counterforce measurement method under a force sensor assembly being tilted under a force;

FIG. 18 shows a flow diagram of a method of counter force measurement according to an embodiment of the invention; and

fig. 19 shows a flow chart of a reaction force measuring method according to another embodiment of the invention.

Detailed Description

The following detailed description of embodiments of the invention refers to the accompanying drawings. It should be understood that the detailed description and specific examples, while indicating embodiments of the invention, are given by way of illustration and explanation only, not limitation.

It should be noted that, the orientation relationship described in the embodiments of the present invention is described by taking the case where the force sensor assembly is vertically placed (the bearing area is above and the supporting area is below), and in the case where the placing direction of the force sensor assembly is changed, the orientation relationship may also be changed correspondingly. The terms "surround", "annular" and the like mean a closed ring formed in various shapes such as a square, a circle and the like. In addition, the force sensor assembly provided by the invention can be used for detecting transverse force besides vertical force.

An embodiment of the present invention provides a force sensor assembly, which may include: the upper surface of the bearing area is used for bearing the load applied by the structure to be tested; a fixed region for mechanical connection with a structure under test, wherein the fixed region is disposed around the load-bearing region; the strain sensitive area is positioned below the fixed area, and one or more groups of strain gauges are arranged on the inner wall of the cavity of the strain sensitive area, wherein each group of strain gauges form a bridge circuit; and a support region below the strain sensitive region for supporting.

The load bearing zone, anchor zone, strain sensitive zone, support zone may each be a separate component, or preferably the load bearing zone, anchor zone, strain sensitive zone, support zone may be integrally formed.

The support region may be provided with an annular groove. The annular groove can block the dispersion of a force transmission path of the sensor assembly, so that the strain of the strain sensitive area is insensitive to the contact force distribution change at the bottom of the supporting area, and the measurement precision is improved. The annular groove is arranged, so that when the force sensor assembly provided by the invention is used as a reaction sensor assembly to measure reaction force, the influence of the distribution change of the reaction contact surface on measurement can be reduced, and the measurement accuracy of the reaction force is improved.

The strain sensitive region may be any suitable structure provided with a cavity, and may be, for example, a cylindrical strain sensitive region, preferably a cylindrical strain sensitive region, but is not limited thereto, and may also be, for example, a square cylindrical strain sensitive region or other types of strain sensitive regions.

The support area is preferably of the ball head type. Under the condition that the supporting area is the supporting area, a bottom foot supporting plate can be further arranged, and the ball head type supporting area and the bottom foot supporting plate can be in contact connection through a ball head ball socket pair, so that the supporting effect is achieved. The support areas may also be of a cuboid shape, in which case the footing support plates may not be provided.

The inner side section of the annular groove is in a circular arc shape or other transitional circular arc shapes. The annular groove may be provided in the lower half of the support region. The groove ring of the annular groove can be a ring with the same height or a ring with different heights. The height (or average height) of the grooves is too small, stress concentration on the inner side is easily formed, the height is too large, the structural strength is reduced, and safety risk exists, and the proper height of the grooves is 1/10 to 1/2 of the diameter of the support area. Similarly, the necking diameter of the annular groove is too large, the contact force breaking effect is insignificant, and the necking diameter is too small, affecting the structural strength, so that a suitable necking diameter is 1/5 to 9/10 of the diameter of the support zone. In the case of a support region of the ball head type, the diameter of the support region is the diameter of the ball head type of sphere. In the case of a support zone of the cuboid type, the diameter of the support zone is the cuboid transverse width.

The opening of the annular groove may preferably face horizontally to the outside, but the embodiment of the present invention is not limited thereto, and the opening direction of the annular groove may be set to be arbitrary, and the opening direction may face a direction at an arbitrary angle with the horizontal direction, for example, the opening direction may be obliquely upward or obliquely downward. The provision of a horizontally outwardly facing annular groove opening is more advantageous to machine than annular grooves in other directions and such an arrangement minimizes material removal and structural load bearing losses.

The fixation region may mechanically connect the force sensor assembly to the structure under test via a transition piece structure, and the fixation region may mechanically connect to the transition piece structure via a fastener. The fasteners may be, for example, bolts or the like. In an alternative, the fastening region may also be fastened to the transition piece structure by welding. Additionally, it will be appreciated that the use of a transition piece structure may not be required if the structure being measured matches the structure of the force sensor assembly. The fixed area is directly connected with the tested structure mechanically.

The bearing area can be arranged as a stop table, and the stop table has the advantages of resisting horizontal lateral force and avoiding the sliding dislocation of the bearing area. The stop abutment may be a stop boss or a stop recess. It will be appreciated that the location of the load bearing zone is not limited to a stop and may be other types of load bearing zones, for example, the middle of the load bearing zone may not have a cavity as the stop.

The stop abutment may preferably be a stop boss, since the upper surface of the stop boss is located at a greater distance from the strain gauge on which the strain sensitive area is located, thus providing greater measurement accuracy. The stop boss may be annular and the wall thickness of the stop boss may be arranged to be greater than the wall thickness of the strain sensitive region. The transition between the stop lug and the strain sensitive region may have a thickness variation such that the wall thickness of the stop lug is greater than the wall thickness of the barrel-type strain sensitive region. This may be advantageous to reduce the strain effect of the detent boss contact force distribution on the barrel strain sensitive area. This is because the contact surface of the stopper boss is increased, so that the contact stress is reduced; and the thickness of the opening of the stop boss is increased, the structural rigidity is increased, and the contact stress distribution is not easily influenced by deformation. The beneficial effect who sets up like this is that the distribution of strain of cylinder type strain-sensitive area is very even, is favorable to eliminating the precision influence that foil gage process error brought for measurement accuracy is very high.

In order to form the strain sensitive region required by the strain gauge, while making the stress distribution of the sensing region more uniform, and considering the structural strength safety, the wall thickness of the strain sensitive region is preferably reduced to 50% to 95% of the wall thickness of the stop boss.

The fixation section and transition piece structure may be configured to be a tight fit or a clearance fit, preferably both. In the process of loading the stress sensor assembly, the upper surface of the bearing area in the normal load transfer relationship is a load bearing surface, however, the stress sensor assembly body can generate tiny compression elastic deformation, and the fixed area partially bears partial load. In order to keep only the bearing region carrying the load and to avoid that the fixation region carries the load partially, at least a part of the upper surface of the fixation region may be provided with a clearance fit with the transition piece structure, i.e. at least a part of the connection surface between the fixation region and the transition piece structure may be provided with a clearance. For example, it may be particularly provided that a portion of the upper surface of the fixing zone is in close contact with the transition piece structure and another portion is in clearance fit with the transition piece structure. For example, one half of the upper surface of the fixation section may be provided in intimate contact with the transition piece structure and the other half of the upper surface may be provided in clearance fit with the transition piece structure. Alternatively, the upper surfaces of the fixation areas may all be provided in clearance fit with the transition piece structure.

A suitable gap size u (also referred to as height) is required to prevent the portion of the clearance fit from taking part of the load due to the compressive elastic deformation. The size u (which may be referred to as height) of the gap is set to satisfy the requirement of equation 1 below:

wherein, F _m For the rated load of the leg, A is the area of the upper surface of the stop boss (i.e., the area of the load acting surface), h is the height of the boss, and E is the reaction force of the legThe modulus of elasticity of the material of the sensor component, k, is a safety factor and is a known value.

The size u of the gap must have sufficient redundancy design in consideration of machining errors, but the excessive gap brings requirements on sealing, safety, protection and the like, so the comprehensive consideration of the surface gap u is preferably in the range of 0.1mm to 1.0 mm. It should be noted that the size of the gap according to the embodiment of the present invention refers to the size of the gap when the force sensor assembly is not loaded.

The gap may be filled with a sealant, which will not be described herein. May be used to seal dust or the like from outside the sensor assembly. The sealant is preferably a soft sealant, such as a weatherable soft sealant. Because the elastic modulus difference of the metal and the soft sealant is very large, the force transmitted by the sealant can be ignored, and the detection precision is not influenced.

The stress sensor assembly provided by the embodiment of the invention has the following advantages:

(1) The annular groove is formed in the supporting area, so that the force transmission path of the sensor assembly can be blocked from being dispersed, the strain of the strain sensitive area is insensitive to the contact force distribution change at the bottom of the supporting area, and the measurement precision is improved;

(2) The strain gauge can be mechanically connected with a structure to be measured and matched with a strain gauge arranged in a cavity of the strain sensitive area, so that the stress of the equipment can be monitored in real time;

(3) The method has the advantages of high reliability, high comprehensive precision, good dynamic measurement performance, low delay and the like, can ensure the bearing safety and the protective performance, and has small change on the whole engineering machine and convenient maintenance and replacement when being applied to the engineering machine.

The force sensor assembly provided by the invention can be used for measuring the counter force of any structure to be measured, or can be used for measuring horizontal side force and the like (in the case that the force sensor assembly is inclined). Alternatively, the force sensor assembly may be used as a leg reaction force sensor assembly to measure leg reaction forces.

In the related art, a method for detecting the magnitude of the counterforce of the support leg by the engineering machine is generally realized by detecting the oil pressure of the support leg oil cylinder, but the method has the following defects: (1) An oil pressure sensor needs to be arranged in the oil cylinder for detecting the oil pressure, so that the risk of oil leakage is increased; (2) Due to the factors of friction, lateral load, pressure abandoning and the like, the oil pressure thrust and the supporting force are possibly greatly different, so that the measurement precision is very low, and the maximum error is more than 15%; (3) The oil pressure measurement mode is that the landing leg load is transmitted to the pressure sensor through hydraulic oil, is an indirect measurement of the reaction force, has serious hysteresis of signal, and the maximum hysteresis is more than 5 s. The stress sensor assembly provided by the invention is used as a support leg reaction force sensor assembly to measure the support leg reaction force, so that the defects can be avoided.

When the sensor assembly is applied as a supporting leg reaction force sensor assembly, the fixed area can be mechanically connected with a vertical oil cylinder piston rod body of a supporting leg through a transition connecting piece structure, wherein the transition connecting piece structure is fixed at the vertical supporting oil cylinder piston rod body of the supporting leg.

Next, the force receiving sensor assembly of the present invention will be exemplified as a leg reaction force sensor assembly by way of example. In each embodiment, the bearing area is a stop boss, the strain sensitive area is a cylindrical strain sensitive area, and the support area is a ball-head support area, i.e., the preferred embodiment using the bearing area, the strain sensitive area, and the support area is used as an example to illustrate the force sensor assembly. It will be appreciated that in other embodiments, the implementation of the load bearing, strain sensitive, and support regions may be a combination of any of these alternative implementations. In the embodiments described below, the force sensor assembly is also referred to as a leg reaction force sensor assembly.

Fig. 1 shows a schematic view of the installation of a force-receiving sensor assembly as a leg reaction force sensor assembly according to an embodiment of the present invention. As shown in fig. 1, the leg reaction force sensor assembly 3 can be mechanically connected to the piston rod body of the vertical support cylinder 2 of the leg and installed below the leg beam 1 of the construction machine. The leg reaction force signals detected by the leg reaction force sensor assembly 3 can be transmitted to the main controller by wire (e.g. by cable) or wirelessly (e.g. by radio), and the main controller derives further operation instructions by integrating the leg reaction force signals of a plurality of legs, or calculates required information such as the total weight, the position of the center of gravity, the safety state, etc.

Fig. 2 to 4 show a first embodiment of a leg reaction force sensor assembly according to an embodiment of the present invention. As shown in fig. 2, the leg reaction force sensor assembly 3.2b may be mechanically connected to the vertical support cylinder piston rod body 2.1 (a portion of which is shown in fig. 2) of the leg by a transition piece structure 3.1 b. The transition piece structure 3.1b may be integrally connected to the vertical support cylinder ram body 2.1, for example, by a filler weld process, the weld location being shown as b-1. The transition piece structure 3.1b may be cylindrical to match the shape of the vertical support cylinder ram body 2.1, and the overall width of the transition piece structure 3.1b may be slightly greater than the diameter of the vertical support cylinder ram body 2.1 or both may be substantially the same. The bottom of the transition piece structure 3.1a may be hollowed out in a portion, and the diameter of the hollowed out portion may be the same as the diameter of the stop bosses, respectively, to accommodate the stop bosses.

The fixing area of the leg reaction sensor assembly may be arranged as a ring, the diameter of which may be substantially the same as the diameter of the transition piece structure 3.1b, in the alternative, the fixing area may also be arranged as a square, etc. In this embodiment, the fixed area is an annular area, and the fixed area is referred to as an annular area in the detailed description. The annular region may be mechanically connected to the transition piece structure 3.1b by fasteners. The fastener may be, for example, bolt b-2. As shown in fig. 3 (a) to 3 (b), the annular region may be provided with a plurality of bolt holes, which may be evenly distributed. The transition piece structure 3.1b is provided with the same number of bolt holes to achieve a mechanical connection of the two by means of bolts b-2.

The annular region upper surface b-3 is clearance fit with the transition piece structure 3.1b, preferably in the range of 0.1mm to 1.0mm, or may be determined according to equation (1). The gap may be filled with, for example, a weatherable soft sealant.

The upper surface b-4 of the stop boss is in intimate contact with the transition piece structure 3.1 b. The upper surface b-4 of the stop boss can bear the load of the support leg during operation. The stop boss may be an annular stop boss.

The structure of the support region may be a portion of a spherical structure or substantially the entire spherical structure. As shown in fig. 2, the overall width of the support region may be greater than that of the cylinder-type strain sensitive region and less than that of the annular region. The support area can be connected with the foot support plate 4b through a ball-and-socket friction pair b-5 in a contact manner. The surface portion of the support area in contact with the foot support plate 4b is arcuate. When the supporting leg is retracted, the supporting base of the foot can be hung at the contraction part of the supporting leg reaction force sensor assembly through structures such as an upper cover plate or a locking pin.

As shown in fig. 4, in this embodiment, the leg reaction force sensor assembly includes: a stop boss 3.2b-1, an annular zone 3.2b-2, the annular zone comprising a plurality of bolt holes, a cylindrical strain sensitive zone 3.2b-3 and a support zone 3.2b-4. N1 in fig. 4 represents the applied load (i.e., the load carried by the upper surface of the stopper boss), and the broken line represents the load path in the leg reaction force sensor assembly, and F represents the resultant force of the contact load. The counterforce of the support leg is the vertical component of the resultant force of the contact load. A schematic diagram of the positive pressure force of the leg reaction force sensor assembly is shown in fig. 4. The stop boss 3.2b-1, the annular zone 3.2b-2, the barrel-type strain sensitive zone 3.2b-3 and the support zone 3.2b-4 may be integrally formed.

The wall thickness of the stop boss 3.2b-1 may be set larger than the wall thickness of the barrel-type strain sensitive area 3.2 b-3. The stop boss 3.2b-1 may have a thickness variation at the transition 3.2b-6 to the barrel-type strain sensitive area 3.2b-3 such that the wall thickness of the stop boss 3.2b-1 is greater than the wall thickness of the barrel-type strain sensitive area 3.2 b-3. This may be advantageous to reduce the strain effect of the detent boss contact force distribution on the barrel strain sensitive area. This is because the contact surface of the stopper boss is increased, so that the contact stress is reduced; and the thickness of the opening of the stop boss is increased, the structural rigidity is increased, and the contact stress distribution is not easily influenced by deformation. The beneficial effect who sets up like this is that the distribution of strain of barrel-type strain sensitive area is very even, is favorable to eliminating the precision influence that foil gage process error brought for measurement accuracy is very high.

In order to form the strain sensitive region required for the strain gauge, while making the stress distribution of the sensing region more uniform, and considering the structural strength safety, the wall thickness of the barrel-type strain sensitive region is preferably reduced to 50% to 95% of the wall thickness of the stopper boss.

The embodiment of the invention also has certain limitation on the bolt pretightening force used for mechanical connection with the transition connecting piece structure. As can be seen from the load path shown by the dotted line in fig. 4, the bolt pretightening force transmission path does not pass through the cylindrical strain sensitive area and is far away from the installation position of the strain patch, so that the influence on the measurement result of the support leg reaction force sensor assembly is small. However, when the pretightening force of the bolt is too large, the cylindrical structure is radially deformed, and the transverse strain is deviated. Therefore, when the supporting leg reaction force sensor assembly is used, the pretightening force of the bolt needs to be adjusted within a reasonable range, and the stability of initial output is ensured. Preferably, the bolt pretension force is reasonably in the range of 10 N.m to 80 N.m.

The support areas 3.2b-4 may be provided with annular grooves 3.2b-7 which may reduce the effect of changes in the contact force distribution of the support areas on the strain of the barrel-type strain sensitive areas. As can be seen from the load transmission path shown by the dotted line in fig. 4, the load is concentrated at the bottom portion of the foot supporting plate, thereby blocking the dispersed transmission of the contact force of the foot supporting plate, so that the strain of the cylinder type strain sensitive region is insensitive to the variation of the contact force distribution. The blocking effect of the annular groove is shown in fig. 5. The transmission path of the leg reaction force in the leg reaction force sensor assembly is shown by the dark area in the figure.

As shown in fig. 6, the inside cross-section of the annular groove is in the shape of a circular arc or other transitional circular arc. The annular groove may be provided in the lower half of the support region. The groove ring of the annular groove may be of the same height as shown or of different heights. The height of the groove is too small, stress concentration on the inner side is easy to form, the height is too large, the structural strength can be reduced, safety risks exist, and the appropriate height dimension H of the groove is 1/10D to 1/2D, wherein D is the diameter of the supporting area. Similarly, the necking diameter of the annular groove is too large, the contact force breaking effect is insignificant, and the necking diameter is too small, affecting the structural strength, so that a suitable necking diameter D is 1/5D to 9/10D, where D is the diameter of the support zone.

The design of the annular groove has the beneficial effects that when a large load is applied, the contact relation is severe or the offset load is applied, the strain of the cylindrical strain sensitive area is insensitive to the contact force distribution change of the bottom of the ball head by the annular groove, so that high measurement precision is formed.

One or more groups of strain gauges 3.2b-5 can be stuck on the inner wall of the cavity of the cylinder type strain sensitive area 3.2b-3 at proper height, and each group of strain gauges can comprise 4 strain gauge pairs which are annularly and symmetrically arranged. The strain gage pair may include transversely and longitudinally arranged strain gages arranged in the same position to form a T-shape or an inverted T-shape. Each set of strain gages may form a bridge circuit. The proper height is the place where the strain of the stress analysis is more uniform. In any embodiment of the present invention, the strain gauge pairs are preferably arranged in a T shape or an inverted T shape, and optionally, the strain gauge pairs may also be arranged in an L shape or an inverted L shape, or any other shape.

Fig. 7 shows a schematic diagram of a bridge circuit formed by strain gauges. In fig. 7, rv1 and Rh1, rv2 and Rh2 \8230 \ 8230, strain gauge pairs are provided, wherein Rv1 and Rv2 \8230, represents vertically arranged strain gauges, rh1 and Rh2 \8230, and represents transversely arranged strain gauges. Ui is the input voltage of the bridge circuit, and Uo is the output voltage. The side of the annular area can be provided with a cable hole, and a cable connected with the output of the bridge circuit extends out of the supporting leg counter-force sensor assembly through the cable hole. The output of the bridge circuit may also be transmitted wirelessly.

In this embodiment, one set of strain gauges is only used for example, and multiple sets of strain gauges may be disposed in the cavity of the barrel-type strain sensitive area. Different strain gauge groups can be arranged at different heights or the same height, and each strain gauge pair of the same strain gauge group is arranged at the same height.

Fig. 8 shows a leg reaction force load path transfer diagram. As shown in fig. 8, the leg reaction force load path is: the ground is greater than a footing support plate, a landing leg counter-force sensor component, a vertical oil cylinder, a combined landing leg beam and an engineering machine frame, wherein the ground is in contact with the footing support plate, the footing support plate is in contact connection with the landing leg counter-force sensor component through a ball head and ball socket pair, the landing leg counter-force sensor component is welded with the vertical oil cylinder through a transition connecting piece structure, the vertical oil cylinder is mechanically connected with the combined landing leg beam, and the combined landing leg beam and the engineering machine frame are stressed through a sliding block. Landing leg reaction force sensor subassembly direct embedding is in landing leg reaction force transmission route, therefore does not have other transmission routes to share the landing leg reaction and leads to landing leg reaction force sensor subassembly to measure the deviation, and the dynamometry direction of landing leg reaction force sensor subassembly is the vertical atress direction of perpendicular hydro-cylinder to structure itself is movable bulb structure, can effectively reduce the influence of side load to measurement accuracy.

A second embodiment of the leg reaction force sensor assembly according to the embodiment of the present invention is shown in fig. 9 to 11. As shown in fig. 9, the leg reaction force sensor assembly 3.2a may be mechanically connected to the vertical support cylinder piston rod body 2.1 (a portion of which is shown in fig. 2) of the leg by a transition piece structure 3.1 a. The transition piece structure 3.1a may be integrally connected to the vertical support cylinder ram body 2.1, for example, by a filler weld process, the weld location being shown as a-1. The transition piece formation 3.1a may be cylindrical to match the shape of the vertical support cylinder ram body 2.1 and may be substantially the same diameter. The bottom of the transition piece structure 3.1a may be hollowed out in a portion, and the diameter of the hollowed out portion may be the same as the diameter of the stop bosses, respectively, to accommodate the stop bosses.

The fixing area of the leg reaction sensor assembly may be arranged as a ring, the diameter of which may be substantially the same as the diameter of the transition piece structure 3.1a, in the alternative, the fixing area may also be arranged as a square, etc. In this embodiment, the fixed area is an annular area, and the fixed area is referred to as an annular area in the detailed description. The annular region may be mechanically connected to the transition piece structure 3.1a by fasteners. The fastener may be, for example, bolt a-2. As shown in fig. 10 (a) to 10 (c), the annular region may be provided with a plurality of bolt holes, which may be evenly distributed. The transition piece structure 3.1a is provided with the same number of bolt holes to achieve a mechanical connection of the two by means of bolts a-2.

One part of the upper surface of the annular region is in close contact with the transition piece structure 3.1a, and the other part a-3 is in clearance fit with the transition piece structure 3.1a, and the clearance can be filled with a weather-resistant soft sealant for example. For example, one half of the upper surface of the annulus may be provided in intimate contact with the transition piece structure 3.1a and the other half may be provided in clearance fit with the transition piece structure 3.1 a.

The upper surface a-4 of the stop boss is in intimate contact with the transition piece structure 3.1 a. The upper surface a-4 of the stop boss can bear the load of the support leg during operation. The stop boss may be an annular stop boss. In this embodiment, the stop boss, the annular region and the barrel-type strain sensitive region have cavities of substantially the same diameter. The diameter of the cavity of the cylinder type strain sensitive area can also be larger than the diameter of the cavity of the stop lug boss and the annular area, so that a better strain sensitive effect can be formed in the cylinder type strain sensitive area.

The structure of the support region may be a portion of a spherical structure or substantially the entire spherical structure. As shown in fig. 3 (b), the overall width of the support region may be greater than that of the cylinder-type strain sensitive region and less than that of the annular region. The support area can be in contact connection with the foot support plate 4a via a ball-and-socket friction pair a-5. The surface portion of the support area in contact with the foot support plate 4a is arcuate. When the supporting leg is retracted, the supporting base of the foot can be hung at the contraction part of the supporting leg reaction force sensor assembly through structures such as an upper cover plate or a locking pin.

As shown in fig. 4, in this embodiment, the leg reaction force sensor assembly includes: a stop boss 3.2a-1, an annular zone 3.2a-2 containing a plurality of bolt holes, a cylindrical strain sensitive zone 3.2a-3 and a support zone 3.2a-4. N1 in fig. 4 represents the applied load (i.e., the load carried by the upper surface of the stopper boss), and the broken line represents the load path in the leg reaction force sensor assembly, and F represents the resultant force of the contact load. The counterforce of the support leg is the vertical component of the resultant force of the contact load. A schematic diagram of the positive pressure force of the leg reaction force sensor assembly is shown in fig. 4. The stop boss 3.2a-1, the annular zone 3.2a-2, the barrel-type strain sensitive zone 3.2a-3 and the support zone 3.2a-4 may be integrally formed. The landing leg reaction force sensor assembly provided by the embodiment has the advantages of simple and compact structure, high reliability, high unbalance loading resistance, high safety and the like.

The wall thickness of the stop boss 3.2a-1 may be set substantially equal to the wall thickness of the barrel-type strain sensitive area 3.2 a-3. Alternatively, the wall thickness of the stop boss 3.2a-1 may be made greater than the wall thickness of the barrel-type strain sensitive area 3.2a-3, similar to the first embodiment, to reduce the effect of the stop boss contact force distribution on the barrel-type strain sensitive area strain.

One or more groups of strain gauges 3.2a-5 can be stuck on the inner wall of the cavity of the cylinder type strain sensitive area 3.2a-3 at proper height, and each group of strain gauges can comprise 4 strain gauge pairs which are annularly and symmetrically arranged. The strain gage pair may include transversely and longitudinally arranged strain gages arranged in the same position to form a T-shape or an inverted T-shape. Each set of strain gages may form a bridge circuit. The proper height is the place where the strain of the stress analysis is more uniform. In any embodiment of the present invention, it is only preferable that the strain gauge pairs are arranged in a T shape or an inverted T shape, and optionally, the strain gauge pairs may be arranged in an L shape or an inverted L shape, or any other shape.

In this embodiment, the bridge circuit formed by the strain gauge is the same as the bridge circuit shown in fig. 7, and will not be described again. In addition, similarly, a plurality of groups of strain gauges can be arranged in the cavity of the cylinder type strain sensitive area. Different strain gauge groups can be arranged at different heights or the same height, and each strain gauge pair of the same strain gauge group is arranged at the same height.

In this embodiment, the limitation of the size of the gap in the clearance fit, the limitation of the bolt pretightening force, the transmission of the counterforce load path of the leg, and the like are the same as those of the first embodiment of the leg counterforce sensor assembly provided by the embodiment of the present invention, and will not be described again here.

When the stress sensor assembly provided by the embodiment of the invention is used as a supporting leg reaction force sensor assembly, the following advantages are achieved:

(1) The device is less influenced by installation and is insensitive to a contact boundary, particularly, the arranged annular groove can block the force transmission path dispersion of the sensor assembly, so that the strain of the cylindrical strain sensitive area is insensitive to the contact force distribution change at the bottom of the supporting area, the influence of the distribution change of the counterforce contact surface of the supporting leg on measurement is reduced, and the measurement precision is improved.

(2) When the supporting legs deflect, the connecting bolt is enabled to be hardly subjected to shearing force due to the design of the stop boss, the deflecting load is borne by the contact force of the front face and the side face of the boss, the fracture risk of the bolt is reduced, and the anti-deflecting load safety is high.

(3) The transition connecting piece structure and the oil cylinder piston rod body are welded into a whole, the supporting leg reaction force sensor assembly is disassembled and assembled only by fastening or loosening the connecting bolt, and the initial output (zero deviation) is insensitive to the variation of the pretightening force of the bolt because the bolt installation position is not between the supporting leg reaction force action position and the strain measurement area, so that the installation and the maintenance are convenient.

(4) On the other hand, the strategy that the supporting zone is provided with the annular groove can structurally reduce errors caused by uncertainty of contact points of the supporting zone, and improve the measurement accuracy of the counterforce of the supporting leg under the conditions of lateral loads such as deformation of the supporting leg, inclination of a supporting plate of the bottom leg, inclined suspension and the like.

Next, a counter force measuring method and device will be described, which can be any type of counter force, such as a leg counter force or other similar counter forces. The method and apparatus are applicable to any force sensor assembly described in any embodiment of the present invention, or any other sensor assembly that detects a counter force using a bridge circuit formed by strain gauges disposed in a strain sensitive region. The force sensor assembly according to any of the embodiments of the present invention is mainly described as an example.

The reaction force measuring precision of the stressed sensor assembly is related to structural factors of the elastic body of the sensor, and is also related to using environment factors such as assembling conditions, stress conditions, using conditions and the like. In practice, the structure to be measured (e.g., a leg structure) may deflect under load in relation to the position of the center of gravity, the total weight, and the ground conditions, which may cause the force sensor assembly to tilt and to receive lateral forces. As shown in fig. 12, the stop boss receives an axial load N1 and a side load N2, where F denotes a resultant contact load. In some cases, the foot support plate tilting may also cause the force sensor assembly to experience lateral forces. This will result in a deviation of the measured value of the counter force measured using conventional methods from the actual vertical counter force. When the stress sensor assembly is used, the contact part of the support area and the bottom supporting plate is fully lubricated, and under the condition that the support area is a ball head type support area, the tangential friction force of a ball head contact surface can be ignored, and then the contact force of the ball head type support area can be along the negative normal direction of the bottom surface of the ball head type support area.

In order to solve the technical problem, an aspect of the embodiments of the present invention provides a reaction force measuring device, as shown in fig. 13, where the reaction force measuring device may include: an included angle measuring module 1310, configured to obtain an included angle between a resultant force of the contact load borne by the force sensor assembly and the central axis, and obtain an included angle between a plane formed by the resultant force of the contact load and the central axis and a plane formed by the central axis and an installation position of a strain gauge in a strain sensitive area of the force sensor assembly; an inclination angle detecting device 1320, configured to detect inclination angles of an X axis, a Y axis, and a Z axis in a three-dimensional cartesian coordinate system with a gravity direction, respectively, where the Z axis in the three-dimensional cartesian coordinate system is a central axis of the force sensor assembly, and the X axis points to an installation position of the strain gauge; and a controller 1330, configured to obtain the counter force borne by the force sensor assembly according to an angle between the resultant force of the contact loads, an angle between the resultant force of the contact loads and the central axis, an angle between a plane formed by the resultant force of the contact loads and the central axis and a plane formed by the central axis and an installation position of a strain gauge, and angles between an X axis, a Y axis, and a Z axis in the three-dimensional cartesian coordinate system and the gravity direction, respectively.

The tilt angle detection device 1320 may be a tilt angle sensor or an acceleration sensor, which may be disposed at the bottom of the strain sensitive area (e.g., the bottom of the cavity of the barrel-type strain sensitive area), preferably fixed at the center of the bottom, especially at the very center. The tilt sensor may be any suitable sensor, such as a MEMS tilt sensor. In a three-dimensional cartesian coordinate system of the inclination angle detection device, a Z axis is a central axis of the force sensor assembly, an X axis points to an installation position of a strain gauge (which may be any one of the two sets of strain gauges), and a Y axis is correspondingly determined after the X axis is determined. The inclination angle detection device can detect the included angles gamma of the X axis, the Y axis and the Z axis with the gravity direction respectively _x ,γ _y ,γ _z 。

The angle measurement module 1310 is located on the inner wall of the cavity of the strain sensitive region, and may include 4 pairs of strain gauges arranged circumferentially and symmetrically at a second height of the strain sensitive region of the force sensor assembly. Each of the strain gage pairs includes a transversely disposed strain gage and a longitudinally disposed strain gage configured to be mounted in a T-shape or an inverted T-shape.

Optionally, the angle measurement module 1310 may be a second bridge circuit. Fig. 14 shows a schematic diagram of a second bridge circuit. As shown in fig. 14, the 4 strain pairs are a first strain gauge pair composed of rz1 and Rcc1, a second strain gauge pair composed of rz2 and Rcc2, a third strain gauge pair composed of rz3 and Rcc3, and a fourth strain gauge pair composed of rz4 and Rcc4, respectively, wherein the first strain gauge pair and the third strain gauge pair are symmetrically arranged, and the second strain gauge pair and the fourth strain gauge pair are symmetrically arranged. Each strain gage pair is configured to be installed in a T-shape or an inverted T-shape, wherein longitudinal strain gages are respectively designated as Rzz1, rzz2, rzz3, and Rzz4, and transverse strain gages are respectively designated as Rcc1, rcc2, rcc3, and Rcc4, in the counterclockwise direction from the X-axis. The strain gauges Rcc1 and Rzz3 are connected in series to form a first arm of the second bridge circuit, the strain gauges Rzz1 and Rcc3 are connected in series to form a second arm of the second bridge circuit, the strain gauges Rcc2 and Rzz4 are connected in series to form a third arm of the second bridge circuit, and the strain gauges Rzz2 and Rcc4 are connected in series to form a fourth arm of the second bridge circuit. The first and second arms constitute a first half-bridge of the second bridge circuit, and the third and fourth arms constitute a second half-bridge of the second bridge circuit.

One or more pairs of fixed resistors connected in series are also connected in parallel in the second bridge circuit. As shown in fig. 14, a pair of fixed resistors R connected in series may be connected in parallel in the second bridge circuit. When the second bridge circuit is used, the half-bridge output voltage U of the second bridge circuit needs to be measured _x1 And U _x2 Wherein the input voltage U of the second bridge circuit _i Known in advance. The second bridge circuit formed by the second group of strain gauges is an improved bridge circuit.

Alternatively, the angle measurement module 1310 may be composed of two circuits. For example, the first arm and the second arm in FIG. 14 can be used in series, and two arms can be connected in parallelA pair of fixed resistors R connected together in series constitute one of the two circuits. The third and fourth arms of figure 14 are used in series with two other pairs of fixed resistors R connected together in series, at the same time in parallel, to form the other of the two circuits. Both circuits having the same input voltage U _i . In a similar manner to fig. 14, the output voltages of the two circuits were measured separately.

In a further alternative embodiment, the present invention provides that the counter-force measuring device may further comprise a first bridge circuit. The first bridge circuit consists of 4 pairs of strain gages arranged circumferentially symmetrically at a first height of the strain sensitive area. The processor can also obtain the resultant force of the contact load according to the output voltage of the first bridge circuit and the included angle between the resultant force of the contact load and the central axis.

The two strain gages of each strain gage pair of the first bridge circuit are arranged to be mounted in a T-shape or inverted T-shape at the same position. Fig. 15 shows a schematic diagram of a first bridge circuit. The strain gage comprises 4 strain gage pairs, namely Rz1 and Rc1, rz2 and Rc2, rz3 and Rc3, rz4 and Rc4, wherein each strain gage pair is arranged to be installed in a T shape or an inverted T shape, the longitudinal strain gages are respectively named as Rz1, rz2, rz3 and Rz4, and the transverse strain gages are respectively named as Rc1, rc2, rc3 and Rc4 in the anticlockwise direction by taking an X axis as a starting point. Wherein the strain gauges Rz1 and Rz3 constitute a first arm, rc1 and Rc3 constitute a second arm, rc2 and Rc4 constitute a third arm, and Rz2 and Rz4 constitute a fourth arm. The first arm and the second arm form a first half-bridge, and the third arm and the fourth arm form a second half-bridge. The first bridge circuit formed by the first set of strain gages is a conventional bridge circuit. For the first bridge circuit, measuring the output voltage U of the first bridge circuit _o . The first bridge circuit and the included angle measuring module have the same input voltage U _i 。

In an embodiment of the invention, the first height and the second height are the same or different. The pairs of strain gages of the first and second sets of strain gages may be arranged circumferentially crosswise, with the first and second heights being the same. Under the condition that the first height and the second height are different, the strain gauge pairs of the first group of strain gauges and the second group of strain gauges can have a circumferential included angle or do not have a circumferential included angle.

Each foil gage of first group foil gage with the hoop contained angle between each foil gage of second group foil gage can be understood, the mounted position of arbitrary first foil gage in the first group foil gage arrives the perpendicular straight line of center pin with in the second group foil gage with the mounted position of the adjacent second foil gage of first foil gage arrives contained angle between the perpendicular straight line of center pin, under the condition that two sets of foil gages are not at same height, can map two perpendicular straight lines to the coplanar and confirm the hoop contained angle. The hoop included angle may be any value between 0 degrees and 90 degrees, but is not equal to 0 degrees and 90 degrees. The circumferential angle between each strain gage of the first set of strain gages and each strain gage of the second set of strain gages can be set to be β, as shown in fig. 16. During the calculation, β is a known quantity.

The functions performed by the controller can be configured separately, and in one embodiment the counter-force measuring means can comprise the first bridge circuit, the second bridge circuit and the tilt angle detection device described above. Correspondingly, the embodiment of the invention provides a force sensor assembly which comprises the counterforce measuring device.

Next, a description will be given of a reaction force measuring method provided by an embodiment of the present invention, which is used for a reaction force measuring device and can be executed by a controller. Fig. 17 shows a schematic diagram of some parameters involved in the counter force measurement method in the case of a force applied by tilting the force sensor assembly. As shown in fig. 17, it is assumed that an angle between the resultant force of the contact load and the central axis of the force sensor assembly is α, an angle between a plane formed by the resultant force of the contact load and the central axis of the force sensor assembly and a plane formed by the central axis and a mounting position of a strain gauge (which may be any strain gauge) is θ, and an inner radius of the strain sensitive region is r ₁ The outer radius of the strain sensitive region is r ₂ The vertical distance from the equivalent spherical center of the support area of the stress sensor assembly to the mounting position of the second group of strain gauges is h ₁ 。r ₁ 、r ₂ And h ₁ May be known in advance. The included angles in the embodiments of the present invention are relatively small angles. In the present invention, the ball is an equivalent ballThe center refers to the intersection point of the stress direction in the stress surface of the support area. And under the condition that the supporting area is a ball head type supporting area, the equivalent spherical center is a spherical center O point of the ball head type supporting area. The angle measurement module is taken as the second bridge circuit for explanation.

For a first bridge circuit, measuring an output voltage of the first bridge circuit and having:

in formula (2), U _o Is the output voltage of the first bridge circuit, U _i The input voltage of the first bridge circuit is K, the sensitivity coefficient of the strain gauge is K, v is the Poisson's ratio of the material of the stress sensor assembly, E is the elastic modulus of the material of the stress sensor assembly, and F is the resultant force of the contact load.

From equation 2, the resultant force F of the contact load is the ratio of the included angle α to the output voltage and the input voltage of the first bridge circuit

I.e.:

in the formula (3), f _F () As a function of the resultant contact load force F.

For the second bridge circuit, the voltage output by each of the two half-bridges of the second bridge circuit is measured and recorded as the first half-bridge voltage U _x1 And a second half-bridge voltage U _x2 The second bridge circuit and the first bridge circuit may have the same input voltage U _i Then, it has:

in the formula:

the function f for calculating alpha can be obtained from formulas 4, 5 and 6 _α ()：

Accordingly, a function f can be obtained for calculating θ _θ ()：

Substituting equation 7 into equation 3 yields the resultant force of the contact load, which is:

while the actual reaction force F _G The vertical component of the resultant force F for the contact load is:

F _G ＝F×(cosαcosγ _z +sinαcosθcosγ _x +sinαsinθcosγ _y ) (formula 10)

Based on the formulas (2) to (10), the first embodiment of the reaction force measuring method according to the present invention, as shown in fig. 18, may include the following steps:

in step S1710, an included angle α between the resultant force of the contact load borne by the force-receiving sensor assembly and the central axis of the force-receiving sensor assembly, an included angle θ between the plane formed by the central axis and the installation position of a strain gauge in the strain sensitive area of the force-receiving sensor assembly are obtained.

Alpha, theta can be obtained according to equations 4-8. Or any other suitable method may be used to obtain α, θ.

In step S1720, tilt angles γ between the X-axis, the Y-axis, and the Z-axis and the gravity direction in the three-dimensional Cartesian coordinate system are detected _x ,γ _y ,γ _z 。

The Z axis in the three-dimensional Cartesian coordinate system is a central axis of the stress sensor assembly, and the X axis points to the installation position of the strain gauge. Gamma ray _x ,γ _y ,γ _z Can be detected by a tilt angle detection device.

In step S1730, according to the resultant force F of the contact load, the included angle α between the resultant force of the contact load and the central axis, the included angle θ between the plane formed by the resultant force of the contact load and the central axis and the plane formed by the central axis and the installation position of a strain gauge, and the included angles γ between the X-axis, the Y-axis, and the Z-axis in the three-dimensional cartesian coordinate system and the gravity direction _x ,γ _y ,γ _z Obtaining the reaction force F borne by the stress sensor assembly _G 。

Wherein the output voltage U can be based on the first bridge circuit _o And obtaining the resultant contact load force F according to an included angle alpha between the resultant contact load force and the central axis, wherein the resultant contact load force F can be obtained according to a formula 2 or 3. Alternatively, the resultant contact load force F may be detected using other force sensor assemblies.

The reaction force F borne by the force sensor assembly can be obtained according to the formula (10) _G 。

Furthermore, substituting equations 8 and 9 into equation 10 results in calculating the reaction force F _G Function f of _g ()：

According to the derivation process, the following steps are carried out: the calculation functions of α and θ are both related to the two half-bridge output voltages of the second bridge circuit, i.e., α and θ can be calculated from the two half-bridge output voltages of the second bridge circuit; reaction force F _G Is the output voltage U of the first bridge circuit _o Two half-bridge output voltages U of a second bridge circuit _x1 And U _x2 Angle of gamma _x ,γ _y ,γ _z As a function of (c).

Based on the formula (11), taking the example that the reaction force measuring apparatus may include the first bridge circuit, the second bridge circuit and the inclination angle detecting device, the second embodiment of the reaction force measuring method provided by the present invention, as shown in fig. 19, may include the following steps:

in step S1810, the output voltage U of the first bridge circuit is obtained _o 。

In step S1820, a first half-bridge voltage U output by each of two half-bridges of the second bridge circuit is obtained _x1 And a second half-bridge voltage U _x2 。

In step S1830, included angles γ between the X-axis, the Y-axis, and the Z-axis of the three-dimensional Cartesian coordinate system detected by the tilt detector and the gravity direction are obtained _x 、γ _y 、γ _z 。

Output voltage U of first bridge circuit output by reaction force sensor assembly _o A first half-bridge voltage U of a second bridge circuit _x1 And a second half-bridge voltage U _x2 Angle of gamma _x 、γ _y 、γ _z May be provided to the controller by wire or wirelessly.

In step S1840, according to the output voltage U of the first bridge circuit _o The first half-bridge voltage U _x1 The second half-bridge voltage U _x2 And the included angles gamma between the X axis, the Y axis and the Z axis and the gravity direction respectively _x 、γ _y 、γ _z To calculate the reaction force F _G 。

In the first embodiment, after obtaining the parameters according to steps 1910 to 1930, in step S1940, an angle α between the resultant force of the contact load and the central axis, and an angle θ between a plane formed by the resultant force of the contact load and the central axis and a plane formed by the central axis and a mounting position of a strain gauge may be obtained according to the first half-bridge voltage and the second half-bridge voltage. Specifically, α may be calculated according to equation 7, and θ may be calculated according to equation 8. And then, obtaining the resultant force of the contact load according to the output voltage of the first bridge circuit and the included angle alpha between the resultant force of the contact load and the central axis, and specifically, calculating according to a formula 3 to obtain the resultant force of the contact load. And then, obtaining the counter force according to the contact load resultant force, the included angle between the contact load resultant force and the central axis, the included angle between the plane formed by the contact load resultant force and the central axis and the plane formed by the central axis and the installation position of a strain gauge, and the included angles between the X axis, the Y axis and the Z axis in the three-dimensional Cartesian coordinate system and the gravity direction respectively. Specifically, the reaction force can be calculated according to equation 10.

In the second embodiment, after obtaining the respective parameters according to steps 1810 to 1830, the reaction force may be calculated using a function for calculating the reaction force obtained in advance in step S1840.

In an alternative case, the function for calculating the counter force can be derived in advance from equations 2, 4, 5, 6, 10.

In another alternative, the reaction force F is known according to equation 11 _G The output voltage of the first bridge, the output voltages of the two half-bridges of the second bridge and the included angle gamma _x ,γ _y ,γ _z In the case of the function of (3), the function f for calculating the reaction force may be obtained by fitting experimental data using a neural network algorithm in advance _g () The model of (1). The input of the neural network algorithm is the independent variable in formula 11, and the output is the counterforce F _G 。

The intermediate parameters α, θ, resultant force of contact load, etc. obtained in the first embodiment can be used for calculating other parameters if necessary, while the second embodiment can calculate the reaction force more efficiently and quickly in real time.

The counter-force measuring method and the counter-force measuring device provided by the embodiment of the invention can effectively solve the influence of the side load on the counter-force measurement caused by deflection deformation, inclination of the bottom foot supporting plate and the like, and effectively improve the counter-force measurement precision.

Correspondingly, the embodiment of the invention also provides engineering machinery, and the engineering machinery is provided with the counter force measuring device or the stress sensor assembly according to any embodiment of the invention. The engineering device can be a crane and a pump truck. Fire engine, etc., the measured counter force may be a leg counter force.

Accordingly, an embodiment of the present invention further provides a machine-readable storage medium, where the machine-readable storage medium has instructions stored thereon, and the instructions are configured to cause a machine to perform: a method of measuring a counterforce according to any embodiment of the invention.

As will be appreciated by one skilled in the art, embodiments of the present application may be provided as a method, system, or computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.

The computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart block or blocks.

The computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

In a typical configuration, a computing device includes one or more processors (CPUs), input/output interfaces, network interfaces, and memory.

The memory may include forms of volatile memory in a computer readable medium, random Access Memory (RAM) and/or non-volatile memory, such as Read Only Memory (ROM) or flash memory (flash RAM). The memory is an example of a computer-readable medium.

Computer-readable media, including both non-transitory and non-transitory, removable and non-removable media, may implement information storage by any method or technology. The information may be computer readable instructions, data structures, modules of a program, or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static Random Access Memory (SRAM), dynamic Random Access Memory (DRAM), other types of Random Access Memory (RAM), read Only Memory (ROM), electrically Erasable Programmable Read Only Memory (EEPROM), flash memory or other memory technology, compact disc read only memory (CD-ROM), digital Versatile Disks (DVD) or other optical storage, magnetic cassettes, magnetic tape magnetic disk storage or other magnetic storage devices, or any other non-transmission medium, which can be used to store information that can be accessed by a computing device. As defined herein, a computer readable medium does not include a transitory computer readable medium such as a modulated data signal and a carrier wave.

It should also be noted that the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrases "comprising one of 8230; \8230;" 8230; "does not exclude the presence of additional like elements in a process, method, article, or apparatus that comprises the element.

The above are merely examples of the present application and are not intended to limit the present application. Various modifications and changes may occur to those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the scope of the claims of the present application.

Claims (18)

1. A reaction force measuring device characterized by comprising:

the included angle measuring module is used for acquiring an included angle between resultant force of contact load borne by the stress sensor assembly and a central axis of the stress sensor assembly, and acquiring an included angle between a plane formed by the resultant force of the contact load and the central axis and a plane formed by the central axis and a mounting position of a strain gauge in a strain sensitive area of the stress sensor assembly;

the inclination angle detection device is used for detecting included angles between an X axis, a Y axis and a Z axis in a three-dimensional Cartesian coordinate system and the gravity direction respectively, wherein the Z axis in the three-dimensional Cartesian coordinate system is a central axis of the stress sensor assembly, and the X axis points to the installation position of the strain gauge; and

and the controller is used for obtaining the counter force born by the stress sensor assembly according to the contact load resultant force, the included angle between the contact load resultant force and the central axis, the included angle between the plane formed by the contact load resultant force and the central axis and the plane formed by the central axis and the installation position of a strain gauge, and the included angles between the X axis, the Y axis and the Z axis in the three-dimensional Cartesian coordinate system and the gravity direction.

2. The apparatus of claim 1, wherein the angle measurement module comprises a second set of strain gages in the strain sensitive region, wherein the second set of strain gages comprises 4 strain gage pairs arranged circumferentially symmetrically at a second height of the strain sensitive region of the force sensor assembly, wherein each strain gage pair comprises a transversely arranged strain gage and a longitudinally arranged strain gage configured to be mounted in a T-shape or an inverted T-shape.

3. The apparatus of claim 2, wherein the angle measurement module is a second bridge circuit, wherein in the second bridge circuit:

a first arm is composed of a transversely arranged strain gage of a first strain gage pair and a longitudinally arranged strain gage of a third strain gage pair, and a second arm is composed of a longitudinally arranged strain gage of the first strain gage pair and a transversely arranged strain gage of the third strain gage pair, wherein the first arm and the second arm constitute a first half bridge of the second bridge circuit, and wherein the first strain gage pair and the third strain gage pair are symmetrically arranged;

a third arm consisting of a transversely arranged strain gage of a second strain gage pair and a longitudinally arranged strain gage of a fourth strain gage pair, a fourth arm consisting of a longitudinally arranged strain gage of the second strain gage pair and a transversely arranged strain gage of the fourth strain gage pair, wherein the third arm and the fourth arm constitute a second half bridge of the second bridge circuit, wherein the second strain gage pair and the fourth strain gage pair are arranged symmetrically,

and one or more pairs of fixed resistors connected in series are also connected in parallel in the second bridge circuit.

4. The apparatus of claim 3,

the device further comprises a first bridge circuit consisting of 4 pairs of strain gages arranged circumferentially symmetrically at a first height of the strain sensitive region; and

the controller is further configured to obtain a resultant force of the contact load according to the output voltage of the first bridge circuit and an included angle between the resultant force of the contact load and the central axis.

5. The device of any one of claims 1 to 4, wherein the force sensor assembly comprises:

the upper surface of the bearing area is used for bearing the load applied by the structure to be tested;

a fixed region for mechanical connection with a structure under test, wherein the fixed region is disposed around the load-bearing region;

the strain sensitive area is positioned below the fixed area and is provided with a cavity; and

and the support region is positioned below the strain sensitive region to play a supporting role.

6. The apparatus of claim 5,

the included angle measuring module is positioned on the inner wall of the cavity of the strain sensitive area; and

the inclination angle detection device is located in the support area.

7. The apparatus of claim 5, wherein the tilt detection device is located at a bottom center of the support area.

8. A reaction force measuring device characterized by comprising:

the first bridge circuit is composed of a first group of strain gauges arranged in a strain sensitive area of the stress sensor assembly;

the second bridge circuit is arranged for acquiring an included angle between a resultant force of a contact load borne by the stress sensor assembly and a central axis of the stress sensor assembly, and acquiring an included angle between a plane formed by the resultant force of the contact load and the central axis and a plane formed by the central axis and an installation position of a strain gauge in the strain sensitive area of the stress sensor assembly; and

and the inclination angle detection device is arranged at the bottom of the strain sensitive area and is used for detecting included angles between an X axis, a Y axis and a Z axis in a three-dimensional Cartesian coordinate system and the gravity direction respectively, wherein the Z axis in the three-dimensional Cartesian coordinate system is the central axis, and the X axis points to the installation position of a strain gauge.

9. A reaction force measuring method for use in the reaction force measuring apparatus according to claim 8, the method comprising:

acquiring an included angle between a resultant force of a contact load borne by a stress sensor assembly and a central axis of the stress sensor assembly, and acquiring an included angle between a plane formed by the resultant force of the contact load and the central axis and a plane formed by the central axis and an installation position of a strain gauge in a strain sensitive area of the stress sensor assembly;

detecting included angles between an X axis, a Y axis and a Z axis in a three-dimensional Cartesian coordinate system and the gravity direction respectively, wherein the Z axis in the three-dimensional Cartesian coordinate system is a central axis of the stress sensor assembly, and the X axis points to the installation position of the strain gauge; and

and obtaining the counter force born by the stress sensor assembly according to the contact load resultant force, the included angle between the contact load resultant force and the central axis, the included angle between the plane formed by the contact load resultant force and the central axis and the plane formed by the central axis and the installation position of a strain gauge, and the included angles between the X axis, the Y axis and the Z axis in the three-dimensional Cartesian coordinate system and the gravity direction.

10. The method of claim 9, further comprising:

and obtaining the resultant force of the contact load according to the output voltage of the first bridge circuit and the included angle between the resultant force of the contact load and the central axis.

11. The method of claim 9, wherein obtaining an angle between the resultant contact load force and the central axis, and obtaining an angle between a plane formed by the resultant contact load force and the central axis and a plane formed by the central axis and a mounting location of a strain gage in a strain sensitive area of the force sensor assembly, comprises: acquiring an included angle between the resultant force of the contact load and the central axis, and an included angle between a plane formed by the resultant force of the contact load borne by the stress sensor assembly and the central axis and a plane formed by the central axis and the mounting position of a strain gauge in a strain sensitive area of the stress sensor assembly according to the following formulas:

wherein the content of the first and second substances,

wherein, U _i Is the input voltage of the second bridge circuit, v is the Poisson's ratio of the material of the force-receiving sensor component, E is the elastic modulus of the material of the force-receiving sensor component, r ₁ Is the inner radius of the strain sensitive region, r ₂ Is the outer radius of the strain sensitive area, alpha is the included angle between the resultant force of the contact load and the central axis, U _x1 Is a first half-bridge voltage, U, of said second bridge circuit _x2 For the second half-bridge voltage of the second bridge circuit, θ is the contact load resultant force and the included angle between the plane formed by the central axis and the plane formed by the mounting positions of the central axis and the strain gauge, β is the circumferential included angle between each strain gauge of the first group of strain gauges and each strain gauge of the second group of strain gauges, h ₁ The vertical distance from the equivalent spherical center of the support area of the stress sensor assembly to the installation position of the second group of strain gauges.

12. A reaction force measuring method for use in the reaction force measuring apparatus according to claim 8, the method comprising:

acquiring the output voltage of a first bridge circuit;

acquiring a first half-bridge voltage and a second half-bridge voltage which are respectively output by two half-bridges of a second bridge circuit;

acquiring included angles between an X axis, a Y axis and a Z axis in a three-dimensional Cartesian coordinate system detected by an inclination angle detection device and the gravity direction respectively; and

and calculating the counter force according to the output voltage of the first bridge circuit, the first half-bridge voltage, the second half-bridge voltage and the included angles of the X axis, the Y axis and the Z axis with the gravity direction respectively.

13. The method of claim 12, wherein calculating the counter force according to the output voltage of the first bridge circuit, the first half-bridge voltage, the second half-bridge voltage, and the respective angles of the X-axis, the Y-axis, and the Z-axis with respect to the direction of gravity comprises:

the counter force is calculated using a function obtained in advance for calculating the counter force.

14. The method of claim 13, wherein the function for calculating the counter force is pre-calculated by:

from the first bridge circuit, the following equation is derived:

from the second bridge circuit, the following equation is derived:

wherein the content of the first and second substances,

the following equation is obtained from the relationship between the reaction force and the resultant contact load force:

F _G ＝F×(cosαcosγ _z +sinαcosθcosγ _x +sinαsinθcosγ _y )；

a function for calculating the reaction force is obtained from the above equations,

wherein, U _o Is the output voltage of the first bridge circuit, U _i Is the input voltage of the first bridge circuit and the second bridge circuit, K is the sensitivity coefficient of a strain gauge, v is the Poisson's ratio of the material of the force-bearing sensor component, E is the elastic modulus of the material of the force-bearing sensor component, F is the resultant force of the contact load, r is the total force of the contact load ₁ Is the inner radius of the strain sensitive region, r ₂ Is the outer radius of the strain sensitive area, alpha is the included angle between the resultant force of the contact load and the central axis, U _x1 Is said first half-bridge voltage, U _x2 Do the second half-bridge voltage, theta do contact load resultant force with the plane that the axis constitutes with the contained angle between the plane that the mounted position of axis and foil gage constitutes, beta do each foil gage of first group foil gage with hoop contained angle between each foil gage of second group foil gage, h ₁ Is the vertical distance, gamma, from the equivalent spherical center of the support area of the force sensor assembly to the mounting position of the second set of strain gauges _x 、γ _y 、γ _z Respectively, the included angles between the X axis, the Y axis and the Z axis and the gravity direction, F _G Is the counter force.

15. The method of claim 14, wherein the function for calculating the opposing forces is obtained in advance using a neural network algorithm according to the following formula fit:

wherein, F _G Is the counter force, f _g () For calculating the function of said counter-force, U _o Is the output voltage of the first bridge circuit, U _i Is an input voltage of the first bridge circuit and the second bridge circuit, U _x1 Is said first half-bridge voltage, U _x2 Is the second half-bridge voltage, γ _x 、γ _y 、γ _z Are respectively the X axis,And the Y axis and the Z axis form included angles with the gravity direction.

16. Force sensor assembly, characterized in that the force sensor assembly is provided with a counterforce measurement device according to claim 8.

17. A working machine, characterized in that it is provided with a counterforce measuring device according to any of claims 1-7 or with a force sensor assembly according to claim 16.

18. A machine-readable storage medium having instructions stored thereon for causing a machine to perform: the reaction force measuring method according to any one of claims 9 to 11; and/or the counterforce measurement method of any of claims 12 to 15.

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