Torque acquisition system and foot-operated sensor

Abstract

A torque collection system and a pedal sensor, the torque collection system includes: a first full-bridge circuit, the first full-bridge circuit is configured to output a corresponding first strain voltage according to the resistance of the first strain unit and the resistance of the second strain unit; a second full-bridge circuit is configured to output a corresponding second strain voltage according to the resistance of the third strain unit and the resistance of the fourth strain unit; the first strain unit, the third strain unit, the second strain unit and the fourth strain unit are fixed on the pedal transmission shaft in sequence along the circumference of the surface of the pedal transmission shaft; a signal processing circuit is configured to output collection data according to the first strain voltage and the second strain voltage, and calculate the torque transmitted from the pedal transmission shaft to the crank of the bicycle according to the collection data and a preset comparison program. The present application can calculate a more accurate torque transmitted from the pedal transmission shaft to the crank of the bicycle, and realize high-precision seamless collection of torque.

Description

Technical Field

[0001] The present application belongs to the technical field of bicycle electronic accessories, and in particular relates to a torque acquisition system and a pedal sensor. Background Art

[0002] In recent years, cycling has become more and more popular among the public. Power meters, which were once used only by professional athletes, have now attracted more and more attention from amateur players. Moreover, power meters can improve the performance of ordinary enthusiasts even more than that of professional athletes. Because power meters measure the real-time output power rate of riders, amateur athletes can better allocate their physical strength.

[0003] At present, the power meters on the market are roughly divided into chainring power meters, hub power meters, crank power meters, pedal power meters, etc. Among them, pedal power meters are more popular among business enthusiasts because of their easy installation. The principle of pedal power meters is that when the rider applies force to the bicycle pedal, the voltage is collected through the bridge circuit of the sensor, and then the corresponding torque parameters and output power are calculated. Although this type of product can better monitor the rider's power output, there are still some defects in the design.

[0004] The pedal sensors used in traditional pedal power meters usually adopt a single full-bridge circuit method, where a pair of variable resistors are connected to a pair of fixed resistors. This method can only output the maximum voltage value when the force applied by the rider to the pedal is perpendicular to the position of the strain resistor, and the area points for collecting force are relatively small, which cannot accurately reflect the torque and power output applied by the rider. Summary of the invention

[0005] The purpose of this application is to provide a torque collection system and a foot-operated sensor, aiming to solve the problem of inaccurate torque collection existing in traditional foot-operated sensors.

[0006] A first aspect of an embodiment of the present application provides a torque collection system, the torque collection system comprising: a first full-bridge circuit, comprising a first strain unit and a second strain unit, the resistance of the first strain unit and the resistance of the second strain unit change with the force applied to the surface of the pedal transmission shaft of the bicycle, the first full-bridge circuit being configured to output a corresponding first strain voltage according to the resistance of the first strain unit and the resistance of the second strain unit; a second full-bridge circuit, comprising a third strain unit and a fourth strain unit, the resistance of the third strain unit and the resistance of the fourth strain unit change with the force applied to the surface of the pedal transmission shaft of the bicycle, the second full-bridge circuit The full-bridge circuit is configured to output a corresponding second strain voltage according to the resistance value of the third strain unit and the resistance value of the fourth strain unit; the first strain unit, the third strain unit, the second strain unit and the fourth strain unit are fixed on the pedal transmission shaft in sequence along the circumferential direction of the surface of the pedal transmission shaft; a signal processing circuit is connected to the first full-bridge circuit and the second full-bridge circuit, and the signal processing circuit is configured to output collected data according to the first strain voltage and the second strain voltage, and the signal processing circuit is also configured to calculate the torque transmitted from the pedal transmission shaft to the crank of the bicycle according to the collected data and a preset comparison program.

[0007] In one embodiment, the first strain unit, the third strain unit, the second strain unit, and the fourth strain unit are centrally symmetrically arranged on the surface of the pedal transmission shaft in sequence; a center line connecting the first strain unit and the second strain unit is parallel to the axis of the crank, and a center line connecting the third strain unit and the fourth strain unit is perpendicular to the axis of the crank.

[0008] In one embodiment, each of the first strain unit, the third strain unit, the second strain unit and the fourth strain unit includes two strain resistors arranged perpendicular to each other.

[0009] In one embodiment, the first strain unit includes a first strain resistor and a second strain resistor, the second strain unit includes a third strain resistor and a fourth strain resistor, the third strain unit includes a fifth strain resistor and a sixth strain resistor, and the fourth strain unit includes a seventh strain resistor and an eighth strain resistor; the first strain resistor, the second strain resistor, the third strain resistor and the fourth strain resistor are connected in series in sequence to form the first full-bridge circuit, and the connection point between the first strain resistor and the second strain resistor and the connection point between the third strain resistor and the fourth strain resistor are both connected to a power supply; the connection point between the first strain resistor and the fourth strain resistor and the connection point between the second strain resistor and the third strain resistor are the strain voltage output ends of the first full-bridge circuit; the fifth strain resistor, the sixth strain resistor, the seventh strain resistor and the eighth strain resistor are connected in series in sequence to form the second full-bridge circuit, and the connection point between the fifth strain resistor and the sixth strain resistor and the connection point between the seventh strain resistor and the eighth strain resistor are both connected to the power supply; the connection point between the fifth strain resistor and the eighth strain resistor and the connection point between the sixth strain resistor and the seventh strain resistor are the strain voltage output ends of the second full-bridge circuit.

[0010] In one embodiment, the first strain resistor, the fourth strain resistor, the fifth strain resistor and the eighth strain resistor are parallel to each other and perpendicular to the axial direction of the pedal transmission shaft; and the two strain resistors in the same strain unit are perpendicular to each other.

[0011] In one embodiment, the signal processing circuit includes a first operational amplifier and a second operational amplifier; the first operational amplifier is configured to generate a first operational amplifier voltage based on the first strain voltage, and the second operational amplifier is configured to generate a second operational amplifier voltage based on the second strain voltage, and the collected data includes the first operational amplifier voltage and the second operational amplifier voltage.

[0012] In one embodiment, the signal processing circuit further includes a processor, and the processor is configured to calculate the torque transmitted from the pedal transmission shaft to the crank according to the collected data and the preset comparison program.

[0013] In one embodiment, a plurality of supplementary full-bridge circuits are further included, each of which includes two supplementary strain units symmetrically arranged on both sides of the pedal transmission shaft; each of the supplementary strain units is fixed on the pedal transmission shaft along the same circumferential direction of the surface of the pedal transmission shaft as the first strain unit, the second strain unit, the third strain unit and the fourth strain unit.

[0014] A second aspect of an embodiment of the present application provides a pedal sensor, comprising a pedal and a pedal transmission shaft, wherein the pedal is rotatably mounted on the pedal transmission shaft, and the pedal transmission shaft further comprises: a power supply module, a communication module and a torque acquisition system as described above, wherein the power supply module is used to supply power to the communication module and the torque acquisition system, and the communication module is used to connect to an external device to transmit the torque collected by the torque acquisition system and transmitted from the pedal transmission shaft to the crank to the external device.

[0015] In one embodiment, a connecting portion is provided at one end of the pedal transmission shaft, and the connecting portion is used for detachable connection with the crank, and the first strain unit, the second strain unit, the third strain unit and the fourth strain unit are all arranged close to the connecting portion on the pedal transmission shaft.

[0016] Compared with the prior art, the embodiments of the present invention have the following beneficial effects: the force data of the pedal transmission shaft can be collected through the strain unit. At the same time, compared with the prior art, the present application has more strain units. The first strain voltage and the second strain voltage obtained by the first full-bridge circuit and the second full-bridge circuit can more comprehensively and accurately calculate the torque transmitted from the pedal transmission shaft to the crank of the bicycle, thereby achieving high-precision seamless torque collection. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a schematic diagram of the circuit structure of the torque collection system of the first embodiment of the present application;

[0018] Figure 2 It is a front view of the pedal transmission shaft structure of the first embodiment of the present application;

[0019] Figure 3 A top view of the pedal transmission shaft structure of the first embodiment of the present application;

[0020] Figure 4 It is a right side view of the pedal transmission shaft structure of the first embodiment of the present application;

[0021] Figure 5 This is another circuit structure schematic diagram of the torque collection system of the first embodiment of the present application;

[0022] Figure 6 A front view of a pedal transmission shaft structure according to a second embodiment of the present application;

[0023] Figure 7 A schematic diagram of the circuit structure of the torque collection system of the second embodiment of the present application;

[0024] Figure 8 A front view of a pedal transmission shaft structure according to a third embodiment of the present application;

[0025] Fig. 9 A schematic diagram of the circuit structure of a torque collection system according to a third embodiment of the present application;

[0026] Fig.10 This is a schematic diagram of the circuit principle of the foot-operated sensor according to the fourth embodiment of the present application.

[0027] Description of the above drawings: 100, torque acquisition system; 110, first full-bridge circuit; 111, first strain unit; 112, second strain unit; 120, second full-bridge circuit; 121, third strain unit; 122, fourth strain unit; 200, signal processing circuit; 300, pedal transmission shaft; 400, crank; 500, chainring; 600, first supplementary full-bridge circuit; 610, first supplementary strain unit; 620, second supplementary strain unit; 700, second supplementary full-bridge circuit; 710, third supplementary strain unit; 720, fourth supplementary strain unit; 800, power module; 900, communication module. DETAILED DESCRIPTION

[0028] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0029] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0030] It should be understood that the orientation or position relationship indicated by terms such as "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0031] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0032] Figure 1The circuit structure diagram of the torque collection system provided by the first embodiment of the present application is shown. For the convenience of explanation, only the part related to the present embodiment is shown, which is described in detail as follows:

[0033] The torque acquisition system 100 includes: a first full-bridge circuit 110 , a second full-bridge circuit 120 and a signal processing circuit 200 .

[0034] In this embodiment, the first full-bridge circuit 110 includes a first strain unit 111 and a second strain unit 112. The resistance of the first strain unit 111 and the resistance of the second strain unit 112 change with the change of the force applied to the pedal transmission shaft 300 of the bicycle. The first full-bridge circuit 110 is configured to output a corresponding first strain voltage VS1 according to the resistance of the first strain unit 111 and the resistance of the second strain unit 112, so as to collect the force applied to the pedal transmission shaft 300, that is, to collect the force data of the pedal transmission shaft 300. The second full-bridge circuit 120 includes a third strain unit 121 and a fourth strain unit 122. The resistance of the third strain unit 121 and the resistance of the fourth strain unit 122 change with the change of the force applied to the pedal transmission shaft 300 of the bicycle. The second full-bridge circuit 120 is configured to output a corresponding second strain voltage VS2 according to the resistance of the third strain unit 121 and the resistance of the fourth strain unit 122. High-precision collection of the force data of the pedal transmission shaft 300 is achieved through the first full-bridge circuit 110 and the second full-bridge circuit 120.

[0035] like Figure 2 , Figure 3 and Figure 4 As shown, the first strain unit 111, the third strain unit 121, the second strain unit 112 and the fourth strain unit 122 are fixed on the pedal transmission shaft 300 in sequence along the circumferential direction of the surface of the pedal transmission shaft 300; the pedal transmission shaft 300 is vertically fixed to one end of the crank 400, and the other end of the crank 400 can be connected to the center of the chainring 500 of the bicycle to drive the chainring 500 to rotate through the pedal transmission shaft 300 and the crank 400.

[0036] It should be noted that when the strain unit is directly subjected to force, it will deform, and its resistance will change accordingly, resulting in changes in the first strain voltage VS1 and the second strain voltage VS2. In addition, when the pedal transmission shaft 300 is deformed by force, the first strain unit 111, the second strain unit 112, the third strain unit 121 and the fourth strain unit 122 fixed on the pedal transmission shaft 300 will also be deformed accordingly, and the resistance of the first strain unit 111, the resistance of the second strain unit 112, the resistance of the third strain unit 121 and the resistance of the fourth strain unit 122 will change, so that the first strain voltage VS1 and the second strain voltage VS2 will change. The first strain voltage VS1 and the second strain voltage VS2 reflect the force condition of the pedal transmission shaft 300, and realize the collection of the force applied to the pedal transmission shaft 300.

[0037] The signal processing circuit 200 is connected to the first full-bridge circuit 110 and the second full-bridge circuit 120. The signal processing circuit 200 is configured to output collected data based on the first strain voltage VS1 and the second strain voltage VS2. The signal processing circuit 200 is also configured to calculate the torque transmitted from the pedal transmission shaft 300 to the crank 400 of the bicycle based on the collected data and a preset comparison program.

[0038] Specifically, the signal processing circuit 200 includes a first operational amplifier U1 and a second operational amplifier U2; the first operational amplifier U1 is configured to generate a first operational amplifier voltage VF1 according to the first strain voltage VS1, and the second operational amplifier U2 is configured to generate a second operational amplifier voltage VF2 according to the second strain voltage VS2, and the collected data includes the first operational amplifier voltage VF1 and the second operational amplifier voltage VF2. The signal processing circuit 200 also includes a processor U3, which can be a single-chip microcomputer or a microprocessor, and the processor U3 is configured to calculate the torque transmitted from the pedal transmission shaft 300 to the crank 400 according to the collected data and a preset comparison program. The calculation formula of the collected data and the corresponding actual torque can be obtained through preliminary experiments, and then the preset comparison program can be obtained.

[0039] In this embodiment, the first operational amplifier U1 , the second operational amplifier U2 and the processor U3 are all disposed in the pedal transmission shaft 300 .

[0040] In another embodiment, the first operational amplifier U1, the second operational amplifier U2 and the processor U3 are all disposed on a bicycle frame.

[0041] Since the first strain voltage VS1 and the second strain voltage VS2 are differential voltages and have no fixed reference voltage, it is not convenient to process and calculate them. Therefore, the first strain voltage VS1 and the second strain voltage VS2 are respectively converted into the first operational amplifier voltage VF1 and the second operational amplifier voltage VF2 through the first operational amplifier U1 and the second operational amplifier U2, that is, standardized collected data is obtained, so that the processor U3 can calculate the torque transmitted from the pedal transmission shaft 300 to the crank 400 through a preset comparison program based on the collected data.

[0042] In this embodiment, the first strain unit 111 , the third strain unit 121 , the second strain unit 112 , and the fourth strain unit 122 are centrally symmetrically arranged on the surface of the pedal transmission shaft 300 in sequence.

[0043] In this embodiment, as the pedal transmission shaft 300 drives the crank 400 to rotate, the pedal transmission shaft 300 as a whole will rotate in a circle with the chainring 500 as the center, and the surface of the pedal transmission shaft 300 will also be equivalent to rotating with its own axis as the center. Even if the direction of the force applied to the pedal transmission shaft 300 remains unchanged, the point where the force is applied to the pedal transmission shaft 300 will also change accordingly; assuming that the magnitude and direction of the force are constant, since the detection sensitivity of the front of the strain unit is higher than the detection sensitivity of the back or side of the strain unit, the detection sensitivity of a single strain unit will fluctuate continuously during the rotation of the pedal transmission shaft 300. Therefore, the more strain units are set on the pedal transmission shaft 300, the more accurate the force data of the pedal transmission shaft 300 can be obtained, which is convenient for the subsequent calculation of parameters such as torque.

[0044] For example, when the force direction of the pedal transmission shaft 300 is perpendicular to the sides of the first strain unit 111 and the second strain unit 112, the detection sensitivity of the first strain unit 111 and the second strain unit 112 reaches the lowest point, while at this time, the force direction of the pedal transmission shaft 300 is perpendicular to the front of the third strain unit 121 or the fourth strain unit 122, and the detection sensitivity of the third strain unit 121 or the fourth strain unit 122 reaches the highest point. Therefore, high-accuracy collection data can be calculated by the first strain voltage VS1 and the second strain voltage VS2.

[0045] Furthermore, a center line connecting the first strain unit 111 and the second strain unit 112 is parallel to the axis of the crank 400 , and a center line connecting the third strain unit 121 and the fourth strain unit 122 is perpendicular to the axis of the crank 400 .

[0046] It should be noted that when the crank 400 is vertical and the pedal transmission shaft 300 moves to the highest point, the position of the first strain unit 111 is defined as the upper sampling point of the pedal transmission shaft 300, the position of the second strain unit 112 is defined as the lower sampling point of the pedal transmission shaft 300, the position of the third strain unit 121 is defined as the front sampling point of the pedal transmission shaft 300, and the position of the fourth strain unit 122 is defined as the rear sampling point of the pedal transmission shaft 300, wherein the upper sampling point is the highest point on the surface of the pedal transmission shaft 300, and the lower sampling point is the lowest point on the surface of the pedal transmission shaft 300. The position of the pedal transmission shaft 300 at this time is defined as the rotation starting point (i.e., 0°).

[0047] Conventional torque collection devices usually only set strain units at the upper sampling point and the lower sampling point. If the pedal transmission shaft 300 is constantly subjected to a vertical downward force, when the pedal transmission shaft 300 rotates 90°, the force direction is the side of the upper sampling point and the lower sampling point, and the sensitivity of the conventional torque collection device reaches the lowest point. In this embodiment, Figure 5 As shown, during the process of the pedal transmission shaft 300 rotating from 0° to 90°, the sensitivity of the third strain unit 121 and the fourth strain unit 122 continues to increase, and the first strain voltage VS1 and the second strain voltage VS2 can complement each other to achieve high-precision full-range seamless collection of the force data of the pedal transmission shaft 300, especially the collection of the force data of the pedal transmission shaft 300 during the rotation process from 0° to 180°, which is also the most important force stage of the pedal transmission shaft 300.

[0048] In this embodiment, the first strain unit 111 includes a first strain resistor R1 and a second strain resistor R2, the second strain unit 112 includes a third strain resistor R3 and a fourth strain resistor R4, the third strain unit 121 includes a fifth strain resistor R5 and a sixth strain resistor R6, and the fourth strain unit 122 includes a seventh strain resistor R7 and an eighth strain resistor R8;

[0049] The first strain unit 111 includes a first strain resistor R1 and a second strain resistor R2, the second strain unit 112 includes a third strain resistor R3 and a fourth strain resistor R4, the third strain unit 121 includes a fifth strain resistor R5 and a sixth strain resistor R6, and the fourth strain unit 122 includes a seventh strain resistor R7 and an eighth strain resistor R8;

[0050] The first strain resistor R1, the second strain resistor R2, the third strain resistor R3 and the fourth strain resistor R4 are sequentially connected in series to form a first full-bridge circuit 110, the connection point between the first strain resistor R1 and the second strain resistor R2 is connected to the positive electrode of the power supply, and the connection point between the third strain resistor R3 and the fourth strain resistor R4 is connected to the negative electrode of the power supply; the connection point between the first strain resistor R1 and the fourth strain resistor R4 and the connection point between the second strain resistor R2 and the third strain resistor R3 are strain voltage output terminals of the first full-bridge circuit 110;

[0051] The fifth strain resistor R5, the sixth strain resistor R6, the seventh strain resistor R7 and the eighth strain resistor R8 are connected in series in sequence to form a second full-bridge circuit 120, the connection point between the fifth strain resistor R5 and the sixth strain resistor R6 is connected to the positive electrode of the power supply, and the connection point between the seventh strain resistor R7 and the eighth strain resistor R8 is connected to the negative electrode of the power supply; the connection point between the fifth strain resistor R5 and the eighth strain resistor R8 and the connection point between the sixth strain resistor R6 and the seventh strain resistor R7 are the strain voltage output ends of the second full-bridge circuit 120.

[0052] In this embodiment, the calculation formulas of the first operational amplifier voltage VF1 and the first strain voltage VS1 are:

[0053]

[0054] The calculation formula of the second op amp voltage VF2 and the second strain voltage VS2 is:

[0055] Where Vcc is the operating voltage of the power supply.

[0056] It should be noted that, when the pedal transmission shaft 300 is not subjected to force, the first full-bridge circuit 110 and the second full-bridge circuit 120 maintain a balanced bridge, and the first strain voltage VS1 and the second strain voltage VS2 are both 0. When the pedal transmission shaft 300 is subjected to force and deformed, the resistance of the strain resistor changes, resulting in a voltage difference between the two output ends of the first full-bridge circuit 110 and the two output ends of the second full-bridge circuit 120, so that the first full-bridge circuit 110 and the second full-bridge circuit 120 output the first strain voltage VS1 and the second strain voltage VS2 respectively. The two strain voltages are combined to realize the collection of the force data of the pedal transmission shaft 300.

[0057] Taking the first strain unit 111 and the second strain unit 112 as an example, if the pedal transmission shaft 300 is deformed so that the side where the first strain unit 111 is located is stretched, the side where the second strain unit 112 is located is correspondingly compressed. At this time, the resistance values ​​of the first strain resistor R1 and the third strain resistor R3 decrease, and the resistance values ​​of the second strain unit 112 and the fourth strain unit 122 increase. Then, in the first full-bridge circuit 110, the voltage at the connection point between the first strain resistor R1 and the fourth strain resistor R4 increases, and the voltage at the connection point between the second strain resistor R2 and the third strain resistor R3 decreases, and a voltage difference appears between the two connection points, so that the first full-bridge circuit 110 outputs a first strain voltage VS1.

[0058] Compared with the traditional full-bridge circuit using a pair of strain resistors and a pair of fixed resistors, under the same conditions such as the force magnitude and force direction, the present embodiment can output a larger range of values ​​of the strain voltage. For example, in the first strain circuit, if the first strain unit 111 is stretched and the second strain unit 112 is compressed, the first strain resistor R1 and the fourth strain resistor R4 will make the voltage at the connection point between the first strain resistor R1 and the fourth strain resistor R4 higher, and the second strain resistor R2 and the third strain resistor R3 will make the voltage at the connection point between the second strain resistor R2 and the third strain resistor R3 lower, the voltage difference between the two connection points is larger, and the value of the output first strain voltage VS1 is larger.

[0059] The strain circuit of this embodiment has a higher sensitivity. Any change in resistance of any of the four strain units will cause a change in the strain voltage. Even if only one strain unit changes in resistance, a larger strain voltage will be output. For example, when the pedal transmission shaft 300 is only slightly stretched at the first strain unit 111, the resistance of the first strain resistor R1 decreases, and the resistance of the second strain resistor R2 increases, which will cause a significant change in the first strain voltage VS1.

[0060] At the same time, the accuracy of this embodiment is higher, the error of a single strain resistor has a smaller impact on the strain voltage, and the error of the output strain voltage is smaller.

[0061] In this embodiment, the first strain resistor R1, the fourth strain resistor R4, the fifth strain resistor R5 and the eighth strain resistor R8 are parallel to each other and perpendicular to the axial direction of the pedal transmission shaft 300; the second strain resistor R2, the third strain resistor R3, the sixth strain resistor R6 and the seventh strain resistor R7 are parallel to each other and perpendicular to the first strain resistor R1, the fourth strain resistor R4, the fifth strain resistor R5 and the eighth strain resistor R8 respectively.

[0062] It should be noted that when the pedal transmission shaft 300 is deformed, the surface of the pedal transmission shaft 300 will be stretched or compressed. The arrangement of the strain resistors mentioned above, combined with the circuit connection method of the first full-bridge circuit 110 and the second full-bridge circuit 120 mentioned above, can further improve the accuracy of force data collection. For example, if the surface of the pedal transmission shaft 300 where the first strain unit 111 is located is stretched, the resistance value of the second strain resistor R2 will increase, and the resistance value of the first strain resistor R1 will decrease. The first strain resistor R1 and the second strain resistor R2 can be compared with each other, which has a higher accuracy of force data collection than setting a single strain resistor in a single strain unit, and the processor U3 can thereby calculate a more accurate torque.

[0063] In another embodiment, the strain resistors of the same strain unit can be parallel to each other, and the connection relationship of the strain resistors in the full-bridge circuit should be changed accordingly to achieve the same effect as the first embodiment. Figure 5 As shown, all the strain resistors are parallel to each other. At this time, the first strain resistor R1, the third strain resistor R3, the second strain resistor R2 and the fourth strain resistor R4 are connected in series in sequence to form a first full-bridge circuit 110, the connection point of the first strain resistor R1 and the third strain resistor R3 is connected to the positive electrode of the power supply, and the connection point of the second strain resistor R2 and the fourth strain resistor R4 is connected to the negative electrode of the power supply; the connection point of the first strain resistor R1 and the fourth strain resistor R4 and the connection point of the second strain resistor R2 and the third strain resistor R3 are the strain voltage output ends of the first full-bridge circuit 110; the fifth strain resistor R5, the seventh strain resistor R7, the sixth strain resistor R6 and the eighth strain resistor R8 are connected in series in sequence to form a second full-bridge circuit 120, the connection point of the fifth strain resistor R5 and the seventh strain resistor R7 is connected to the positive electrode of the power supply, and the connection point of the sixth strain resistor R6 and the eighth strain resistor R8 is connected to the negative electrode of the power supply; the connection point of the fifth strain resistor R5 and the eighth strain resistor R8 and the connection point of the sixth strain resistor R6 and the seventh strain resistor R7 are the strain voltage output ends of the second full-bridge circuit 120. Similarly, the effect of generating the first strain voltage VS1 and the second strain voltage VS2 according to the deformation of the pedal transmission shaft 300 can be achieved.

[0064] Figure 6 A front view of a pedal transmission shaft structure provided in a second embodiment of the present application is shown. For ease of description, only the parts related to this embodiment are shown, which are described in detail as follows:

[0065] Different from the first embodiment, the present embodiment further includes a first supplementary full-bridge circuit 600, the first supplementary full-bridge circuit 600 includes a first supplementary strain unit 610 and a second supplementary strain unit 620, wherein Figure 7As shown, the first supplementary strain unit 610 includes a ninth strain resistor R9 and a tenth strain resistor R10, and the second supplementary strain unit 620 includes an eleventh strain resistor R11 and a twelfth strain resistor R12.

[0066] The ninth strain resistor R9, the tenth strain resistor R10, the eleventh strain resistor R11 and the twelfth strain resistor R12 are sequentially connected in series to form a first supplementary full-bridge circuit 600, the connection point between the ninth strain resistor R9 and the tenth strain resistor R10 is connected to the positive electrode of the power supply, and the connection point between the eleventh strain resistor R11 and the twelfth strain resistor R12 is connected to the negative electrode of the power supply; the connection point between the ninth strain resistor R9 and the twelfth strain resistor R12 and the connection point between the tenth strain resistor R10 and the eleventh strain resistor R11 are strain voltage output terminals of the first supplementary full-bridge circuit 600;

[0067] The circuit structure of the first supplementary full-bridge circuit 600 is the same as that of the first full-bridge circuit 110 . The first supplementary full-bridge circuit 600 is connected to the processor U3 via the third operational amplifier U4 .

[0068] In this embodiment, the first strain unit 111, the first supplementary strain unit 610, the third strain unit 121, the second strain unit 112, the second supplementary strain unit 620 and the fourth strain unit 122 are fixed on the pedal transmission shaft 300 in sequence along the same circumferential direction of the surface of the pedal transmission shaft 300, so as to further improve the sensitivity of the torque acquisition system 100 to force detection at different angles of the pedal transmission shaft 300, so that the processor U3 can calculate a more accurate torque.

[0069] Figure 8 A front view of a pedal transmission shaft structure provided in a third embodiment of the present application is shown. For ease of description, only the parts related to this embodiment are shown, which are described in detail as follows:

[0070] Different from the second embodiment, Figure 8 , Fig. 9As shown, in this embodiment, a second supplementary full-bridge circuit 700 is also included, and the second supplementary full-bridge circuit 700 includes a third supplementary strain unit 710 and a fourth supplementary strain unit 720, wherein the third supplementary strain unit 710 includes a thirteenth strain resistor R13 and a fourteenth strain resistor R14, and the fourth supplementary strain unit 720 includes a fifteenth strain resistor R15 and a sixteenth strain resistor R16. The thirteenth strain resistor R13, the fourteenth strain resistor R14, the fifteenth strain resistor R15 and the sixteenth strain resistor R16 are sequentially connected in series to form the second supplementary full-bridge circuit 700, the connection point of the thirteenth strain resistor R13 and the fourteenth strain resistor R14 is connected to the positive electrode of the power supply, and the connection point of the fifteenth strain resistor R15 and the sixteenth strain resistor R16 is connected to the negative electrode of the power supply; the connection point of the thirteenth strain resistor R13 and the sixteenth strain resistor R16 and the connection point of the fourteenth strain resistor R14 and the fifteenth strain resistor R15 are the strain voltage output terminals of the second supplementary full-bridge circuit 700.

[0071] In this embodiment, the second supplementary full-bridge circuit 700 is connected to the processor U3 through the fourth operational amplifier U5, so that the processor U3 can calculate a more accurate torque. The first strain unit 111, the first supplementary strain unit 610, the third strain unit 121, the third supplementary strain unit 710, the second strain unit 112, the second supplementary strain unit 620, the fourth strain unit 122 and the fourth supplementary strain unit 720 are fixed to the pedal transmission shaft 300 in the same circumferential direction of the surface of the pedal transmission shaft 300.

[0072] The number of supplementary full-bridge circuits can be appropriately increased according to actual needs to further improve the force detection sensitivity.

[0073] Fig.10 The circuit principle diagram of the foot-operated sensor provided in the fourth embodiment of the present application is shown. For the convenience of explanation, only the part related to the present embodiment is shown, which is described in detail as follows:

[0074] like Figure 1-4 As shown, a pedal sensor includes a pedal and a pedal transmission shaft 300, wherein the pedal is rotatably mounted on the pedal transmission shaft 300, and further includes: a power module 800, a communication module 900 and a torque acquisition system 100 as in any of the above embodiments, wherein the power module 800 is used to supply power to the communication module 900 and the torque acquisition system 100, and the power module 800 is the power supply in the first embodiment, and the communication module 900 is used to connect to an external device to transmit the torque collected by the torque acquisition system 100 and transmitted from the pedal transmission shaft 300 to the crank 400 to the external device, and the communication module 900 may be a Bluetooth module or a WIFI transmitting module.

[0075] Further, one end of the pedal transmission shaft 300 is provided with a connecting portion, which is used for detachable connection with the crank 400. In this embodiment, the connecting portion is a threaded rod with external threads arranged at one end of the pedal transmission shaft 300, for threaded connection with the crank 400.

[0076] Furthermore, the first strain unit 111, the second strain unit 112, the third strain unit 121 and the fourth strain unit 122 of the torque collection system 100 are all arranged close to the connection part on the pedal transmission shaft 300. When the pedal transmission shaft 300 is subjected to force, the part of the pedal transmission shaft 300 close to the connection part is the part where the deformation is most obvious, thereby improving the sensitivity of the first strain unit 111, the second strain unit 112, the third strain unit 121 and the fourth strain unit 122, and being able to more comprehensively collect the force data of the pedal transmission shaft 300.

[0077] Furthermore, the processor U3 can calculate the power of work done by the cyclist on the pedal sensor based on the obtained torque.

[0078] A fifth embodiment of the present application provides a bicycle, comprising a frame and two pedal sensors as described in the above embodiments, which are mounted on the frame.

[0079] The embodiments described above are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A torque acquisition system, characterized in that: The torque acquisition system comprises: A first full-bridge circuit includes a first strain unit and a second strain unit, wherein the resistance of the first strain unit and the resistance of the second strain unit change with the force applied to the surface of the pedal transmission shaft of the bicycle, and the first full-bridge circuit is configured to output a corresponding first strain voltage according to the resistance of the first strain unit and the resistance of the second strain unit; a second full-bridge circuit, comprising a third strain unit and a fourth strain unit, wherein the resistance of the third strain unit and the resistance of the fourth strain unit change with the force applied to the surface of the pedal transmission shaft of the bicycle, and the second full-bridge circuit is configured to output a corresponding second strain voltage according to the resistance of the third strain unit and the resistance of the fourth strain unit; The first strain unit, the third strain unit, the second strain unit and the fourth strain unit are sequentially fixed on the pedal transmission shaft along the circumference of the surface of the pedal transmission shaft; a signal processing circuit connected to the first full-bridge circuit and the second full-bridge circuit, the signal processing circuit being configured to output collected data according to the first strain voltage and the second strain voltage, and the signal processing circuit being further configured to calculate the torque transmitted from the pedal transmission shaft to the crank of the bicycle according to the collected data and a preset comparison program; The first strain unit, the third strain unit, the second strain unit, and the fourth strain unit are centrally symmetrically arranged on the surface of the pedal transmission shaft in sequence; A center line connecting the first strain unit and the second strain unit is parallel to the axis of the crank, and a center line connecting the third strain unit and the fourth strain unit is perpendicular to the axis of the crank; The first strain unit, the third strain unit, the second strain unit and the fourth strain unit respectively include two strain resistors arranged perpendicular to each other; The torque collection system also includes a plurality of supplementary full-bridge circuits, each of which includes two supplementary strain units symmetrically arranged on both sides of the pedal transmission shaft surface; Each of the supplementary strain units is fixed on the pedal transmission shaft along the same circumferential direction of the surface of the pedal transmission shaft as the first strain unit, the second strain unit, the third strain unit and the fourth strain unit.

2. The torque acquisition system according to claim 1, characterized in that: The first strain unit includes a first strain resistor and a second strain resistor, the second strain unit includes a third strain resistor and a fourth strain resistor, the third strain unit includes a fifth strain resistor and a sixth strain resistor, and the fourth strain unit includes a seventh strain resistor and an eighth strain resistor; The first strain resistor, the second strain resistor, the third strain resistor and the fourth strain resistor are sequentially connected in series to form the first full-bridge circuit, and the connection point between the first strain resistor and the second strain resistor and the connection point between the third strain resistor and the fourth strain resistor are both connected to a power supply; the connection point between the first strain resistor and the fourth strain resistor and the connection point between the second strain resistor and the third strain resistor are strain voltage output terminals of the first full-bridge circuit; The fifth strain resistor, the sixth strain resistor, the seventh strain resistor and the eighth strain resistor are connected in series in sequence to form the second full-bridge circuit, and the connection point between the fifth strain resistor and the sixth strain resistor and the connection point between the seventh strain resistor and the eighth strain resistor are both connected to the power supply; the connection point between the fifth strain resistor and the eighth strain resistor and the connection point between the sixth strain resistor and the seventh strain resistor are the strain voltage output ends of the second full-bridge circuit.

3. The torque acquisition system according to claim 2, characterized in that: The first strain resistor, the fourth strain resistor, the fifth strain resistor and the eighth strain resistor are parallel to each other and perpendicular to the axial direction of the pedal transmission shaft.

4. The torque acquisition system according to claim 1, characterized in that: The signal processing circuit includes a first operational amplifier and a second operational amplifier; the first operational amplifier is configured to generate a first operational amplifier voltage according to the first strain voltage, the second operational amplifier is configured to generate a second operational amplifier voltage according to the second strain voltage, and the collected data includes the first operational amplifier voltage and the second operational amplifier voltage.

5. The torque acquisition system according to claim 1, characterized in that: The signal processing circuit further includes a processor, and the processor is configured to calculate the torque transmitted from the pedal transmission shaft to the crank according to the collected data and the preset comparison program.

6. A pedal sensor, comprising a pedal and a pedal transmission shaft, wherein the pedal is rotatably mounted on the pedal transmission shaft, and wherein: The pedal transmission shaft also includes: a power module, a communication module and a torque acquisition system as described in any one of claims 1-5, the power module is used to power the communication module and the torque acquisition system, and the communication module is used to connect to an external device to transmit the torque collected by the torque acquisition system and transmitted from the pedal transmission shaft to the crank to the external device.

7. The foot-operated sensor according to claim 6, characterized in that: A connecting portion is provided at one end of the pedal transmission shaft, and the connecting portion is used for detachable connection with the crank, and the first strain unit, the second strain unit, the third strain unit and the fourth strain unit are all arranged close to the connecting portion on the pedal transmission shaft.

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