Design method of rotor wing power system tension integrated measurement system

Abstract

The invention relates to the field of unmanned aerial vehicle rotor wing power systems, in particular to a design method of a rotor wing power system tension integrated measurement system, which comprises the following steps: determining the type of an annular tension sensor according to the obtained size parameter information of a rotor wing motor and the set range and precision requirement of the rotor wing tension to be measured; according to the obtained characteristic size of the annular tension sensor, the size of a structural accessory in the tension integrated measurement system is determined, and an assembly size chain is established; and according to the sizes of the annular tension sensor and the structural accessories, after the size of a replacement motor shaft, the position of a snap spring groove and the size of a mounting seat are determined in combination with the established assembly size chain, a three-dimensional model of the tension integrated measurement system is constructed, and structural integration of the tension sensor and the rotor motor is completed. According to the integrated measuring method for the pulling force, the pulling force of the rotor wing is directly transmitted and measured through the motor shaft instead of inevitable connecting parts in a conventional measuring method, so that the measuring accuracy is improved.

Description

Technical Field

[0001] The invention relates to the field of unmanned aerial vehicle (UAV) rotor power systems, and in particular to a design method for a rotor power system tension integration measurement system. Background Art

[0002] Conventional UAV rotor power systems only have the function of adjusting the speed of the motor and propeller, and the required output thrust is adjusted by changing the speed. If the thrust generated by the rotor power system can be directly controlled, the flight quality of the UAV will be greatly improved when performing large maneuvers such as large attitudes and rapid changes and under strong environmental wind interference. One of the basic and key technologies for achieving closed-loop control of the thrust of the rotor power system is to accurately measure the high-dynamic rotor thrust in real time.

[0003] The mainstream high-precision commercial tension sensors on the market can measure the rotor tension, but there are still some problems that cannot be ignored: First, the separate tension sensor and rotor motor will significantly increase the size and weight of the original power system, which will have an adverse effect on the use and storage of the drone; second, the inevitable slight deviations between the blades during the propeller manufacturing process will cause the propeller to cause high-frequency changing bending moment loads on the tension sensor due to dynamic imbalance during rotation, which can easily damage the torsion beam structure inside the sensor; finally, the indirect force measurement method in which the tension is transmitted from the motor shaft to the motor base and then to the force measuring surface of the tension sensor will limit the measurement accuracy. Summary of the invention

[0004] The purpose of the present invention is to solve the problem that the conventional split tension sensor is faced with the problems of large size and weight, easy damage of structure and insufficient measurement accuracy in measuring rotor tension. A measurement method that tightly couples and integrates the tension sensor with the motor is proposed. The method integrates the annular tension sensor with the motor structure as a whole to achieve integrated measurement of the rotor tension, thereby solving the problem of efficient, high stability and high precision measurement of the rotor tension.

[0005] The technical solution of the present invention is: a design method of a rotor power system pull integration measurement system, which integrates the annular pull sensor with the rotor motor to obtain high-precision rotor pull data in real time, including the following steps:

[0006] 1) Obtain the dimensional parameter information of the rotor motor, and set the range and accuracy requirements for measuring the rotor thrust;

[0007] 2) According to the set range and accuracy requirements for measuring the rotor thrust and the measured outer diameter of the motor shaft, the type of the annular tension sensor is determined, and the characteristic size of the annular tension sensor is obtained;

[0008] 3) According to the characteristic dimensions of the selected annular tension sensor and the principle of matching relationship, the dimensions of the structural accessories in the integrated tension measurement system are determined, and an assembly dimension chain is established based on the acquired accessory dimension information;

[0009] 4) According to the dimensions of the annular tension sensor and structural accessories, combined with the established assembly dimension chain, determine the dimensions of the replacement motor shaft and the position of the retaining ring groove;

[0010] 5) After determining the size of the mounting base based on the annular tension sensor combined with all accessories with confirmed sizes, a three-dimensional model of the tension integrated measurement system is constructed to complete the structural integration of the tension sensor and the rotor motor.

[0011] The method of determining the type of the annular tension sensor is specifically as follows:

[0012] 1-1) Determine the range of the annular tension sensor according to the maximum tension borne by the rotor power system; the range of the annular tension sensor is 1.2 to 1.5 times the maximum tension value to prevent the sensor from being overloaded;

[0013] 1-2) According to the tension measurement accuracy, determine the accuracy level of the annular tension sensor, and select an annular tension sensor with a larger accuracy than the required accuracy; at the same time, determine the diameter of the inner ring of the annular tension sensor according to the outer diameter of the motor shaft;

[0014] 1-3) According to the load capacity and installation space of the rotor power system, select the volume and weight of the annular tension sensor that meets the load capacity and installation space. On this basis, select the annular tension sensor with the smallest comprehensive error, measurement bandwidth and temperature adaptability range that meet the requirements;

[0015] 1-4) Combining steps 1-1) to 1-3), obtaining characteristic dimensions of the selected annular tension sensor;

[0016] The step 3) comprises the following steps:

[0017] 2-1) According to the outer ring width of the annular tension sensor’s fixing surface, determine the outer diameter of the upper bearing according to the clearance fit principle;

[0018] 2-2) Determine the inner diameter of the upper and lower bearings according to the motor shaft diameter, and determine the outer diameter range of the lower bearing according to the interference or transition fit principle and the size of the annular tension sensor;

[0019] 2-3) Determine the size and thickness of the upper and lower contact surfaces of the force transmission member according to the size range of the outer diameter surface of the lower bearing and the size of the force-bearing surface of the annular tension sensor;

[0020] 2-4) Determine the size of the motor shaft retaining spring according to the motor shaft diameter; and determine the size of the fastener according to the motor shaft diameter;

[0021] 2-5) Determine the diameter and length of the fastening screw according to the size of the threaded hole at the bottom of the motor shaft.

[0022] The steps 2-3) are specifically:

[0023] a. Determination of the size of the contact surface under the force transmission part:

[0024] The size of the lower contact surface of the force transmission member matches the size of the outer diameter surface of the lower bearing; the outer diameter of the lower contact surface of the force transmission member is consistent with the outer diameter of the lower bearing;

[0025] b. Determination of the contact surface size on the force transmission part:

[0026] According to the effective transmission of force: the outer diameter of the contact surface on the force transmission member is equal to the outer diameter of the force-bearing surface of the annular tension sensor, so as to ensure that the force can be fully transmitted to the sensor;

[0027] Installation and positioning accuracy: The inner diameter of the contact surface on the force transmission piece is equal to the inner diameter of the force-bearing surface of the annular tension sensor to facilitate alignment and positioning during installation;

[0028] The contact surface on the force transmission member is a plane, and the size of the contact surface evenly covers the force-bearing area of ​​the sensor;

[0029] c. Determination of the thickness of the force transmission parts:

[0030] According to the principle of material mechanics, the minimum thickness required for the force transmission part is determined by calculating the maximum stress that the force transmission part bears during operation and combining the yield strength and allowable stress of the material;

[0031] The deformation of the force transmission part is calculated by the elastic modulus of the material and the size and stress conditions of the force transmission part, and the maximum deformation of the force transmission part should not exceed 0.1% to 0.3% of its size.

[0032] In step 3), the establishment of the assembly dimension chain includes the following steps:

[0033] 3-1) Determine the closed loop and component loops:

[0034] Closed loop determination: In the integrated tension measurement system, select the distance A from the center line of the motor shaft to the outer surface of the mounting seat 0 As a closed loop;

[0035] Determine the motor shaft outer diameter d 2 、Inner diameter of annular tension sensor d 1 and ring width w 1 、Inner diameter of mounting seat D 2 and ring width w 2 The size of the ring is determined;

[0036] 3-2) Draw the dimension chain diagram: connect the component rings and closed rings with line segments according to their positional relationship in the assembly;

[0037] 3-3) According to the dimension chain diagram, analyze the relationship between the dimensions and establish the dimension chain equation;

[0038] 3-4) Calculate tolerance and limit size:

[0039] According to the principle of extreme value method, the upper deviation of the closed loop is equal to the sum of all the upper deviations of the increased loop minus the sum of all the lower deviations of the reduced loop; the lower deviation of the closed loop is equal to the sum of all the lower deviations of the increased loop minus the sum of all the upper deviations of the reduced loop; combined with the tolerance information of each size, the tolerance range of the closed loop is calculated;

[0040] According to the basic size and tolerance range of the closed ring, the maximum limit size and minimum limit size of the closed ring are calculated. The maximum limit size is equal to the basic size plus the upper deviation, and the minimum limit size is equal to the basic size plus the lower deviation.

[0041] The step 4) is specifically:

[0042] 4-1) The diameter of the replacement motor shaft is the same as the original motor shaft diameter to ensure that the motor outer rotor, inner bearing and motor stator structure remain unchanged;

[0043] 4-2) Determine the total length of the replacement motor shaft and the position of the retaining ring groove according to the thickness of the original motor mechanism of the motor outer rotor, inner bearing, and motor stator, as well as the thickness of each structural component that has been determined;

[0044] 4-3) The structural form and materials used for other positions of the replacement motor shaft should be consistent with those of the original motor shaft.

[0045] The step 5) is specifically:

[0046] 5-1) Determine the depth and diameter of each opening according to the determined accessory structure and accessory size;

[0047] 5-2) According to the position and size of the mounting hole at the bottom of the original motor, determine the position and size of the through hole of the mounting base for the integrated installation of the motor, force sensor and accessories;

[0048] 5-3) According to the position and size of the mounting hole at the bottom of the original motor, determine the mounting hole position of the mounting base for fixing the integrated force measurement system to the UAV body;

[0049] 5-4) Connect all the structural and accessory dimensions, build a three-dimensional model of the integrated tension measurement system, and realize the design of the integrated force measurement system.

[0050] When the annular tension sensor is measuring, the real-time tension transmission process is as follows:

[0051] The rotation of the rotor motor drives the propeller to rotate and generates tension. The tension is transmitted to the motor shaft through the outer rotor. The motor shaft drives the lower bearing due to the limit of the retaining spring to transmit the tension to the force surface of the annular tension sensor through the force transmission part. At this time, the annular tension sensor detects the rotor tension data.

[0052] Compared with the conventional tension measurement method, the present invention has the following advantages and beneficial effects:

[0053] 1. The integrated tension measurement method proposed in the present invention deeply couples and integrates the annular tension sensor with the motor structure, thereby reducing the overall structural size of the motor-force sensor and improving space utilization;

[0054] 2. The integrated tension measurement method proposed in the present invention can significantly reduce the adverse bending moment caused by the rotor dynamic imbalance because the eccentric load arm is reduced to the motor shaft radius, thereby ensuring that the force sensor structure is not damaged and improving the measurement stability and reliability.

[0055] 3. In the integrated tension measurement method proposed by the present invention, the rotor tension is directly transmitted and measured through the motor shaft without passing through the inevitable connecting parts in the conventional measurement method, thereby improving the measurement accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Figure 1 It is a schematic diagram of the assembly of the integrated rotor pull measurement system of the present invention;

[0057] Figure 2 It is a schematic diagram of the structure of the integrated rotor pull measurement system of the present invention;

[0058] Among them, 1 is a replacement motor shaft, 2 is the motor outer rotor, 3 is the inner bearing, 4 is the motor stator, 5 is the upper bearing, 6 is the annular tension sensor, 7 is the force transmission part, 8 is the lower bearing, 9 is the motor shaft retaining spring, 10 is the fastener, 11 is the fastening screw, and 12 is the mounting seat. DETAILED DESCRIPTION

[0059] The specific implementation of the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementations.

[0060] like Figure 1 FIG. 1 is a schematic diagram of the assembly of the integrated rotor force measurement system of the present invention. The design method of the integrated rotor force measurement system of the present invention integrates the annular force sensor and the rotor motor into a structurally integrated manner to obtain high-precision rotor force data in real time, and includes the following steps:

[0061] 1) Obtain the dimensional parameter information of the rotor motor, and set the range and accuracy requirements for measuring the rotor thrust;

[0062] The present invention adopts the conventional component size measurement technology in the field for data collection, such as detecting the outer diameter of the motor shaft by a vernier caliper.

[0063] 2) According to the required range and accuracy requirements for measuring the rotor thrust set in the data storage module and the measured outer diameter of the motor shaft, the type of the force sensor is determined to be an annular tension sensor 6, and the characteristic dimensions of the annular tension sensor are obtained;

[0064] 2-1) Determine the measuring range of the annular tension sensor 6 according to the maximum tension borne by the rotor power system; wherein the measuring range of the annular tension sensor 6 is 1.2 to 1.5 times of the maximum tension value measured to prevent the sensor from being overloaded;

[0065] 2-2) According to the tension measurement accuracy, determine the accuracy level of the annular tension sensor 6, and select an annular tension sensor 6 that is greater than the accuracy requirement; at the same time, determine the inner ring diameter of the annular tension sensor 6 according to the outer diameter of the motor shaft;

[0066] 2-3) According to the load capacity and installation space of the rotor power system, the volume and weight of the annular tension sensor 6 that meet the load capacity and installation space are selected. On this basis, the annular tension sensor with the smallest comprehensive error, measurement bandwidth and temperature adaptability range that meet the requirements is selected;

[0067] 2-4) Combining steps 2-1) to 2-3), the characteristic dimensions of the selected annular tension sensor 6 are obtained;

[0068] 3) According to the characteristic dimensions of the selected annular tension sensor 6 and the principle of matching relationship, the dimensions of the structural accessories in the integrated tension measurement system are determined, and an assembly dimension chain is established based on the acquired accessory dimension information;

[0069] 3-1) According to the outer ring width of the fixing surface of the annular tension sensor 6, the outer diameter of the upper bearing 5 is determined according to the clearance fit principle;

[0070] 3-2) Determine the inner diameter of the upper bearing 5 and the lower bearing 8 according to the diameter of the motor shaft, and determine the outer diameter range of the lower bearing 8 according to the interference or transition fit principle and the size of the annular tension sensor 6;

[0071] 3-3) Determine the upper and lower contact surface sizes and thicknesses of the force transmission member 7 according to the outer diameter size range of the lower bearing 8 and the force bearing surface size of the annular tension sensor 6;

[0072] a. Determination of the size of the lower contact surface of the force transmission member 7:

[0073] The size of the lower contact surface of the force transmission member 7 should match the size of the outer diameter surface of the lower bearing 8; the outer diameter of the lower contact surface of the force transmission member 7 is consistent with the outer diameter of the lower bearing 8;

[0074] b. Determination of the size of the upper contact surface of the force transmission member 7:

[0075] According to the effective transmission of force: the outer diameter of the upper contact surface of the force transmission member 7 is equal to the outer diameter of the force-bearing surface of the annular tension sensor 6 to ensure that the force can be fully transmitted to the sensor;

[0076] Installation and positioning accuracy: The inner diameter of the upper contact surface of the force transmission member 7 is equal to the inner diameter of the force-bearing surface of the annular tension sensor 6 to facilitate alignment and positioning during installation;

[0077] The upper contact surface of the force transmission member 7 is a plane, and the size of the upper contact surface evenly covers the force-bearing area of ​​the annular tension sensor 6;

[0078] c. Determination of the thickness of the force transmission member 7:

[0079] According to the principle of material mechanics, the minimum thickness required for the force transmission part is determined by calculating the maximum stress that the force transmission part bears during operation and combining the yield strength and allowable stress of the material;

[0080] The deformation of the force transmission member 7 is calculated by the elastic modulus of the material and the size and force condition of the force transmission member 7, and the maximum deformation of the force transmission member 7 should not exceed 0.1% to 0.3% of its size.

[0081] 3-4) Determine the size of the motor shaft retaining spring 9 according to the motor shaft diameter; and determine the size of the fastener 10 according to the motor shaft diameter;

[0082] 3-5) Determine the diameter and length of the fastening screw according to the size of the threaded hole at the bottom of the motor shaft.

[0083] In the above, the assembly dimension chain is established according to the obtained accessory dimension information. The specific method is as follows:

[0084] (1) Determine the closed loop and component loop:

[0085] Closed loop determination: In the integrated tension measurement system, select the distance A from the center line of the motor shaft to the outer surface of the mounting seat 0 As a closed loop;

[0086] Determine the motor shaft outer diameter d 2 , the inner diameter d of the annular tension sensor 6 1 and ring width w 1 、Inner diameter of mounting seat D 2 and ring width w 2 The size of the ring is determined;

[0087] (2) Draw the dimension chain diagram: connect the component rings and closed rings with line segments according to their positional relationship in the assembly;

[0088] (3) According to the dimension chain diagram, analyze the relationship between the dimensions and establish the dimension chain equation;

[0089] (4) Calculate tolerances and limit sizes:

[0090] According to the principle of extreme value method, the upper deviation of the closed loop is equal to the sum of all the upper deviations of the increased loop minus the sum of all the lower deviations of the reduced loop; the lower deviation of the closed loop is equal to the sum of all the lower deviations of the increased loop minus the sum of all the upper deviations of the reduced loop; combined with the tolerance information of each size, the tolerance range of the closed loop is calculated;

[0091] According to the basic size and tolerance range of the closed loop, calculate the maximum limit size and minimum limit size of the closed loop. The maximum limit size is equal to the basic size plus the upper deviation, and the minimum limit size is equal to the basic size plus the lower deviation;

[0092] In the above-mentioned dimension chain diagram, it is not limited to the annular tension sensor 6 in the present embodiment, and the relationship between the dimensions of all components involved in the present embodiment can be analyzed by constructing a dimension chain diagram; the innovative design of the overall structural dimensions of the motor-force sensor in this embodiment is separately described, which is consistent with the principle of constructing a dimension chain diagram between other components, so it will not be repeated.

[0093] 4) According to the dimensions of the annular tension sensor 6 and the structural accessories, combined with the established assembly dimension chain, determine the dimensions of the replacement motor shaft 1 and the position of the retaining ring groove 9;

[0094] 4-1) The diameter of the replacement motor shaft 1 is the same as the original motor shaft diameter to ensure that the structure of the motor outer rotor 2, inner bearing 3, and motor stator 4 remains unchanged;

[0095] 4-2) Determine the total length of the replacement motor shaft 1 and the position of the retaining ring groove 9 according to the thickness of the original motor mechanism of the motor outer rotor 2, the inner bearing 3, the motor stator 4, and the thickness of each structural component that has been determined;

[0096] 4-3) The structural form of other positions of the replacement motor shaft 1 and the materials used should be consistent with the original motor shaft.

[0097] 5) After determining the size of the mounting base based on the annular tension sensor 6 combined with all accessories with confirmed sizes, a three-dimensional model of the integrated tension measurement system is constructed to complete the structural integration of the annular tension sensor and the rotor motor.

[0098] 5-1) Determine the depth and diameter of each opening according to the determined accessory structure and accessory size;

[0099] 5-2) According to the position and size of the mounting hole at the bottom of the original motor, determine the position and size of the through hole of the mounting base 12 for integrated installation of the motor, the annular tension sensor 6 and accessories;

[0100] 5-3) Determine the mounting hole position of the mounting base 12 according to the position and size of the mounting hole at the bottom of the original motor, so as to fix the integrated force measurement system to the UAV body;

[0101] 5-4) Connect all the structural and accessory dimensions, build a three-dimensional model of the integrated tension measurement system, and realize the design of the integrated force measurement system.

[0102] When the annular tension sensor is measuring, the real-time tension transmission process is as follows:

[0103] The rotation of the rotor motor drives the propeller to rotate and generates tension, which is transmitted to the replacement motor shaft 1 through the motor outer rotor 2. The replacement motor shaft 1 is limited by the motor shaft retaining spring 9 and drives the lower bearing 8 to transmit the tension to the force surface of the annular tension sensor 6 through the force transmission part 7. At this time, the annular tension sensor 6 detects the rotor tension data.

[0104] Embodiment 1:

[0105] This embodiment proposes a design method for a rotor power system pull integrated measurement system. This method integrates the motor and the annular pull sensor by replacing the motor shaft, so that the pull generated by the rotor is directly transmitted to the force sensor through the motor shaft for real-time high-precision measurement, solving the problems of large volume and weight, easy damage to the structure, and poor measurement accuracy that cannot be avoided in conventional motor-force sensor split measurement solutions. The assembly diagram of the rotor pull integrated measurement system designed by the present invention is shown in the attached figure. Figures 1-2 As shown in the exploded view of the assembly, the specific steps of this embodiment are as follows:

[0106] In order to simplify the calculation steps, this embodiment implements the corresponding calculation by designing a host computer, which is implemented by the following hardware methods, including: a data storage module, a measurement module, a sensor type database, and a mapping module;

[0107] The data storage module is used to collect the dimensional parameter information of the rotor motor imported into the host computer and the range and accuracy requirements of the rotor thrust required for measurement, and wait for the measurement module to call;

[0108] The sensor type database is used to store the data of annular tension sensors with various ranges and accuracy requirements, and wait for the measurement module to call;

[0109] The measuring module is used to determine the type of the annular tension sensor according to the range and accuracy requirements of the rotor thrust required to be measured set in the data storage module, and the measured outer diameter size of the motor shaft, in combination with the sensor type database, and obtain the characteristic size of the annular tension sensor, and determine the size of the structural accessories in the tension integrated measurement system according to the selected characteristic size of the annular tension sensor, send all the dimensional parameter data to the mapping module, and determine the size of the replacement motor shaft and the position of the retaining ring groove in the tension integrated measurement system according to the assembly dimension chain fed back by the mapping module;

[0110] The drawing module is used to establish a matching dimension chain based on the dimensions of the annular tension sensor and structural accessories. It also receives all the accessory dimensions determined by the measurement module, builds a tension integrated measurement system model, and sends it to the assembly system for assembly.

[0111] (1) Select the force sensor:

[0112] The force sensor is the core component of the measurement system. Its function is to measure the pull generated by the rotor in real time. First, according to the range and accuracy requirements of the rotor pull measurement and the outer diameter of the motor shaft, select the appropriate annular pull sensor:

[0113] The maximum pulling force of the rotor power system in this embodiment is 4kg, so a 5kg range annular tension sensor 6 can be selected; considering the cost and measurement accuracy, an accuracy level of 5 / 1000 can generally meet the requirements; the inner diameter of the annular tension sensor 6 should be larger than the outer diameter of the motor shaft, and the outer diameter should be as small as possible within the optional range to reduce the overall weight and size of the measurement system.

[0114] Secondly, taking into account the limited load capacity and installation size of the rotor UAV power system, the selected force sensor should meet the volume and weight requirements; in this embodiment, aluminum alloy is used for the main structure to reduce weight while meeting the strength requirements; on this basis, an annular tension sensor with a smaller comprehensive error, a wider measurement bandwidth and a wider temperature adaptability range is selected as much as possible.

[0115] (2) Determine the characteristic dimensions of structural parts:

[0116] In this embodiment, Φ is defined as the outer diameter of a component, φ is defined as the inner diameter of a component, δ is defined as the thickness of a component, and Φ′ or φ′ is defined as the ring width of a component. The specific method is as follows:

[0117] First, according to the outer ring width size Φ′ of the annular force sensor 6 Determine the outer diameter of the upper bearing Φ 5 , Φ 5 Should be consistent with Φ′ 6The size is equal to ensure that the outer edge of the upper bearing only contacts the outer periphery of the annular force sensor fixing surface; according to the motor shaft diameter Φ 1 Determine the inner diameter of the upper bearing φ 5 , usually φ 5 With Φ 1 equal to ensure that the inner ring of the upper bearing rotates with the motor shaft.

[0118] Secondly, according to the motor shaft diameter Φ 1 Determine the inner diameter of the lower bearing φ 8 , usually the bearing inner diameter size φ 8 With motor shaft diameter Φ 1 equal to ensure that the inner ring of the lower bearing rotates with the motor shaft; according to the size of the annular force sensor Φ 6 , determine the outer diameter of the lower bearing Φ 8 Range, inner diameter of lower bearing Φ 8 Usually should be smaller than the size of the annular force sensor Φ 6 The lower bearing 8 is used in conjunction with the upper bearing 5 to provide lateral support to ensure that the motor shaft rotates concentrically without eccentricity, and to prevent the motor shaft from directly contacting the inner ring of the annular force sensor 6, causing inaccurate force measurement.

[0119] Again, according to the outer diameter size Φ of the lower bearing 8 8 and the force-bearing surface size φ of the annular tension sensor 6 6 ', determine the upper and lower contact surface dimensions Φ of the force transmission member 7 7 and φ 7 , and the thickness δ of the force transmission member 7 7 The function of the force transmission member 7 is to transmit the tension transmitted by the motor shaft through the retaining spring and the lower bearing to the force-bearing surface of the annular force sensor. If the outer diameter of the selected lower bearing 8 is Φ 8 Can be directly connected to the force surface size φ of the annular force sensor 6 6 ’, the force transmission parts can be omitted.

[0120] After that, according to the motor shaft diameter 1Φ 1 Determine the inner diameter of the motor shaft retaining spring φ 9 and outer diameter Φ 9 , this size can usually be calculated based on the motor shaft diameter Φ 1 Direct selection, the motor shaft retaining spring 9 is used to fix the position of the force sensor and various structural accessories in the direction of the motor shaft, and at the same time transmit the pulling force of the motor shaft upward; thereafter, according to the motor shaft diameter Φ 1 Determine the inner diameter of the fastener 10 10 and outer diameter Φ 10 , fastener 10 inner diameter φ 10 Should be consistent with the motor shaft diameter Φ 1 Equal, the outer diameter of the fastener 10 Φ 10It should be as small as possible while ensuring strength.

[0121] Finally, according to the size of the threaded hole at the bottom of the motor shaft, the diameter and length of the fastening screw 11 are determined. The fastening screw 11 cooperates with the fastener 10 to fasten the annular tension sensor 6 and various structural accessories to the motor shaft, thereby forming an integrated structure with the motor.

[0122] The third step is to determine the characteristic dimensions of the replacement motor shaft 1. Because the annular tension sensor 6 and structural accessories are added, and the annular tension sensor 6 needs to be integrated with the motor, the original motor shaft needs to be replaced. First, the diameter of the replacement motor shaft Φ 1 The diameter of the replacement motor shaft should be the same as that of the original motor shaft to ensure that the structure of the motor outer rotor, inner bearing, and motor stator remain unchanged and can be used directly; secondly, according to the thickness of the original motor mechanism such as the motor outer rotor, inner bearing, motor stator, and the thickness of each structural component determined in the second step, determine the total length L of the replacement motor shaft 1 and the position of the retaining ring groove 9; finally, the structural form and materials used in other positions of the replaced motor shaft 1 are consistent with those of the original motor shaft.

[0123] According to the above steps, complete Figure 2 The layout of the various parts shown in the figure, and Figure 2 The rotor thrust integrated measurement system shown in FIG. Figure 1 The complete integrated design shown;

[0124] In summary, in the integrated tension measurement method proposed in the present invention, the rotor tension is directly transmitted and measured through the motor shaft without passing through the inevitable connecting components in the conventional measurement method, thereby improving the measurement accuracy.

[0125] The specific implementation modes of the present invention are described above in conjunction with the accompanying drawings, but these descriptions cannot be understood as limiting the scope of the present invention. The protection scope of the present invention is defined by the attached claims, and any changes based on the claims of the present invention are within the protection scope of the present invention.

Claims

1. A design method for a rotor power system pull integration measurement system, characterized in that: The annular force sensor is structurally integrated with the rotor motor to obtain high-precision rotor force data in real time, including the following steps: 1) Obtain the dimensional parameter information of the rotor motor, and set the range and accuracy requirements for measuring the rotor thrust; 2) According to the set range and accuracy requirements for measuring the rotor thrust and the measured outer diameter of the motor shaft, the type of the annular tension sensor is determined, and the characteristic size of the annular tension sensor is obtained; 3) According to the characteristic dimensions of the selected annular tension sensor and the principle of matching relationship, the dimensions of the structural accessories in the integrated tension measurement system are determined, and an assembly dimension chain is established based on the acquired accessory dimension information; 4) According to the dimensions of the annular tension sensor and structural accessories, combined with the established assembly dimension chain, determine the dimensions of the replacement motor shaft and the position of the retaining ring groove; 5) After determining the size of the mounting base based on the annular tension sensor combined with all accessories with confirmed sizes, a three-dimensional model of the tension integrated measurement system is constructed to complete the structural integration of the tension sensor and the rotor motor.

2. The design method of a rotor power system tension integrated measurement system according to claim 1, characterized in that: The method of determining the type of the annular tension sensor is specifically as follows: 1-1) Determine the range of the annular tension sensor according to the maximum tension borne by the rotor power system; the range of the annular tension sensor is 1.2 to 1.5 times the maximum tension value to prevent the sensor from being overloaded; 1-2) According to the tension measurement accuracy, determine the accuracy level of the annular tension sensor, and select an annular tension sensor with a larger accuracy than the required accuracy; at the same time, determine the diameter of the inner ring of the annular tension sensor according to the outer diameter of the motor shaft; 1-3) According to the load capacity and installation space of the rotor power system, select the volume and weight of the annular tension sensor that meets the load capacity and installation space. On this basis, select the annular tension sensor with the smallest comprehensive error, measurement bandwidth and temperature adaptability range that meet the requirements; 1-4) Combine steps 1-1) to 1-3) to obtain the characteristic dimensions of the selected annular tension sensor.

3. The design method of a rotor power system tension integrated measurement system according to claim 1, characterized in that: The step 3) comprises the following steps: 2-1) According to the outer ring width of the annular tension sensor’s fixing surface, determine the outer diameter of the upper bearing according to the clearance fit principle; 2-2) Determine the inner diameter of the upper and lower bearings according to the motor shaft diameter, and determine the outer diameter range of the lower bearing according to the interference or transition fit principle and the size of the annular tension sensor; 2-3) Determine the size and thickness of the upper and lower contact surfaces of the force transmission member according to the size range of the outer diameter surface of the lower bearing and the size of the force-bearing surface of the annular tension sensor; 2-4) Determine the size of the motor shaft retaining spring according to the motor shaft diameter; and determine the size of the fastener according to the motor shaft diameter; 2-5) Determine the diameter and length of the fastening screw according to the size of the threaded hole at the bottom of the motor shaft.

4. The design method of a rotor power system tension integrated measurement system according to claim 3 is characterized in that: The steps 2-3) are specifically: a. Determination of the size of the contact surface under the force transmission part: The size of the lower contact surface of the force transmission member matches the size of the outer diameter surface of the lower bearing; the outer diameter of the lower contact surface of the force transmission member is consistent with the outer diameter of the lower bearing; b. Determination of the contact surface size on the force transmission part: According to the effective transmission of force: the outer diameter of the contact surface on the force transmission member is equal to the outer diameter of the force-bearing surface of the annular tension sensor, so as to ensure that the force can be fully transmitted to the sensor; Installation and positioning accuracy: The inner diameter of the contact surface on the force transmission piece is equal to the inner diameter of the force-bearing surface of the annular tension sensor to facilitate alignment and positioning during installation; The contact surface on the force transmission member is a plane, and the size of the contact surface evenly covers the force-bearing area of ​​the sensor; c. Determination of the thickness of the force transmission parts: According to the principle of material mechanics, the minimum thickness required for the force transmission part is determined by calculating the maximum stress that the force transmission part bears during operation and combining the yield strength and allowable stress of the material; The deformation of the force transmission part is calculated by the elastic modulus of the material and the size and stress conditions of the force transmission part, and the maximum deformation of the force transmission part should not exceed 0.1% to 0.3% of its size.

5. The design method of a rotor power system tension integrated measurement system according to claim 1, characterized in that: In step 3), the establishment of the assembly dimension chain includes the following steps: 3-1) Determine the closed loop and component loops: Closed loop determination: In the integrated tension measurement system, the distance A0 from the motor shaft centerline to the outer surface of the mounting seat is selected as the closed loop; Determine the dimensions of the motor shaft outer diameter d2, the annular tension sensor inner diameter d1 and the ring width w1, the mounting seat inner diameter D2 and the ring width w2, that is, determine the constituent rings; 3-2) Draw the dimension chain diagram: connect the component rings and closed rings with line segments according to their positional relationship in the assembly; 3-3) According to the dimension chain diagram, analyze the relationship between the dimensions and establish the dimension chain equation; 3-4) Calculate tolerance and limit size: According to the principle of extreme value method, the upper deviation of the closed loop is equal to the sum of all the upper deviations of the increased loop minus the sum of all the lower deviations of the reduced loop; the lower deviation of the closed loop is equal to the sum of all the lower deviations of the increased loop minus the sum of all the upper deviations of the reduced loop; combined with the tolerance information of each size, the tolerance range of the closed loop is calculated; According to the basic size and tolerance range of the closed ring, the maximum limit size and minimum limit size of the closed ring are calculated. The maximum limit size is equal to the basic size plus the upper deviation, and the minimum limit size is equal to the basic size plus the lower deviation.

6. The method for designing a rotor power system pull integration measurement system according to claim 1, characterized in that: The step 4) is specifically: 4-1) The diameter of the replacement motor shaft is the same as the original motor shaft diameter to ensure that the motor outer rotor, inner bearing and motor stator structure remain unchanged; 4-2) Determine the total length of the replacement motor shaft and the position of the retaining ring groove according to the thickness of the original motor mechanism of the motor outer rotor, inner bearing, and motor stator, as well as the thickness of each structural component that has been determined; 4-3) The structural form and materials used for other positions of the replacement motor shaft should be consistent with those of the original motor shaft.

7. The method for designing a rotor power system pull integration measurement system according to claim 1, characterized in that: The step 5) is specifically: 5-1) Determine the depth and diameter of each opening according to the determined accessory structure and accessory size; 5-2) According to the position and size of the mounting hole at the bottom of the original motor, determine the position and size of the through hole of the mounting base for the integrated installation of the motor, force sensor and accessories; 5-3) According to the position and size of the mounting hole at the bottom of the original motor, determine the mounting hole position of the mounting base for fixing the integrated force measurement system to the UAV body; 5-4) Connect all the structural and accessory dimensions, build a three-dimensional model of the integrated tension measurement system, and realize the design of the integrated force measurement system.

8. The method for designing a rotor power system pull integration measurement system according to claim 1, characterized in that: When the annular tension sensor is measuring, the real-time tension transmission process is as follows: The rotation of the rotor motor drives the propeller to rotate and generates tension. The tension is transmitted to the motor shaft through the outer rotor. The motor shaft drives the lower bearing due to the limit of the retaining spring to transmit the tension to the force surface of the annular tension sensor through the force transmission part. At this time, the annular tension sensor detects the rotor tension data.

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