Six-dimensional force sensor adopting three-beam structure
By employing a three-beam structure and filtering technology with the MAX11254 chip, a 24-bit high-precision analog-to-digital converter, the problems of high noise and low accuracy in six-dimensional force sensors were solved, achieving higher measurement accuracy and lower production costs.
Patent Information
- Application Number
- CN202520611451.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-02
- Publication Date
- 2026-01-27
- Estimated Expiration
- 2035-04-02
AI Technical Summary
Existing six-dimensional force sensors suffer from significant noise and insufficient measurement accuracy.
The six-dimensional force sensor, which adopts a three-beam structure, uses a 24-bit high-precision analog-to-digital converter chip MAX11254 for filtering. Combined with filter capacitors and the Wheatstone half-bridge principle, it reduces noise and improves accuracy.
This achieves effective noise removal, improves measurement accuracy, and reduces production costs.
Smart Images
Figure CN223841355U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of six-dimensional force sensor technology, and more specifically, to a six-dimensional force sensor employing a three-beam structure. Background Technology
[0002] Force sensors can be categorized into single-dimensional force sensors and multi-dimensional force sensors based on the dimension of force measurement. Among them, multi-dimensional force sensors are capable of simultaneously measuring two or more forces and torques, with six-dimensional force sensors being the most widely used.
[0003] A six-dimensional force sensor is a high-precision measuring device capable of simultaneously measuring three force components (Fx, Fy, Fz) and three torque components (Mx, My, Mz) in three-dimensional space. It typically uses strain gauges as the sensing element. When subjected to an external force, the sensor deforms, causing a change in resistance, thus measuring the force. Each force corresponds to a vector, which has both magnitude and direction. During sensor calibration, the sensor system is assumed to be a linear system, meaning the static mathematical model satisfies a specific mathematical model. The internal algorithm decouples interference between forces and torques in different directions, improving the accuracy of force measurement.
[0004] However, in actual use, there is a problem: the existing six-dimensional force sensors have problems such as significant noise and insufficient measurement accuracy. Utility Model Content
[0005] This invention solves the technical problems of existing six-dimensional force sensors, such as significant noise and insufficient measurement accuracy.
[0006] To address the aforementioned problems, this utility model provides a six-dimensional force sensor employing a three-beam structure, comprising: a signal acquisition board circuit, which includes six analog signal input interfaces and an A / D conversion circuit, wherein the A / D conversion circuit has six ADC ports; the analog signal input interfaces include a positive input interface and a negative input interface, and the ADC ports include a positive input port and a negative input port; wherein the positive input port is connected to the positive input interface, the negative input port is connected to the negative input interface, and a filter capacitor is connected between the positive input interface and the negative input interface.
[0007] Compared with existing technologies, the technical effects achieved by this technical solution are as follows: the pre-filter capacitor connected between the corresponding positive and negative input interfaces filters the analog signal of the bridge board current output, removes noise, and makes the ADC input waveform smoother.
[0008] In one embodiment of this utility model, the ADC conversion circuit uses a 24-bit high-precision analog-to-digital converter chip, MAX11254.
[0009] Compared with existing technologies, the technical advantages achieved by this solution are as follows: It utilizes the MAX11254 chip, a 24-bit high-precision analog-to-digital converter, achieving excellent noise performance while maintaining extremely low power consumption; and it improves the accuracy of the six-dimensional force sensor through oversampling, noise shaping, and digital filtering. Furthermore, the MAX11254 chip features 6-channel acquisition capabilities, a maximum sampling rate of 64ksps, and a built-in 128x adjustable amplifier circuit, offering advantages such as low noise, low power consumption, and high accuracy.
[0010] In one embodiment of this utility model, the six-dimensional force sensor further includes: a bridge circuit, which includes twelve strain gauges and twelve resistors, with each pair of strain gauges and each pair of resistors forming a Wheatstone half-bridge; wherein, the bridge circuit is used to generate voltage signals.
[0011] Compared with existing technologies, the technical advantages achieved by this solution are as follows: This application designs a six-dimensional force sensor using a three-beam structure and the Wheatstone half-bridge principle. The three-beam structure is more compact than common crossbeam and parallel elastic body structures. The bridge board circuit includes 12 resistors and 12 strain gauges. Every two strain gauges and every two resistors form a Wheatstone half-bridge, for a total of six Wheatstone half-bridges, forming six voltage input channels for acquiring strain gauge voltage changes. Furthermore, a common crossbeam structure to form a full Wheatstone bridge typically requires 24 strain gauges, while the three-beam half-bridge structure of this application only requires 12 strain gauges, reducing production costs.
[0012] In one embodiment of this utility model, the signal acquisition board circuit further includes: a main control processing circuit, which is used to process and convert voltage signals into force signals; and an RS485 serial communication circuit, which is used to transmit force signals.
[0013] Compared with existing technologies, the technical effects achieved by this technical solution are as follows: The signal acquisition board circuit is divided into an analog signal input interface, an ADC conversion circuit, a main control processing circuit, and an RS485 serial communication circuit. The bridge board circuit generates a weak voltage signal, which is transmitted to the ADC conversion circuit through the analog signal input interface. Then, the main control processing circuit processes the voltage signal and converts it into a force signal. Finally, the force data (i.e., the force signal) is transmitted through the RS485 serial communication circuit.
[0014] In one embodiment of this utility model, the controller of the main control processing circuit adopts the GD32F303CCT6 chip.
[0015] Compared with existing technologies, the technical effect achieved by adopting this technical solution is as follows: the GD32F303CCT6 chip is used to perform data transmission processing of the ADC through the SPI serial port.
[0016] In one embodiment of this utility model, the RS485 serial communication circuit uses the SIT3485EUA chip in an MSOP-8 package.
[0017] Compared with existing technologies, the technical effects achieved by adopting this technical solution are: the SIT3485EUA chip in MSOP-8 package makes the structure more compact.
[0018] In one embodiment of this utility model, the signal acquisition board circuit further includes a power supply circuit, which includes a first conversion circuit, a second conversion circuit, a third conversion circuit, and a fourth conversion circuit; the first conversion circuit is used for external power supply, the second conversion circuit is used for power supply to the bridge board circuit, the third conversion circuit is used for power supply to the main control processing circuit, and the fourth conversion circuit is used for power supply to the ADC conversion circuit.
[0019] In one embodiment of this utility model, the first conversion circuit uses an HT7463B DC-DC chip; the second and third conversion circuits use an 1117 LDO chip; and the fourth conversion circuit uses a REF3025 chip.
[0020] Compared with existing technologies, the technical effects achieved by this solution are as follows: The signal acquisition board circuit also includes a power supply circuit, which comprises a first conversion circuit, a second conversion circuit, a third conversion circuit, and a fourth conversion circuit. In the entire power supply circuit, analog signals and digital signals are separated, improving data sampling accuracy and avoiding interference. The first conversion circuit is used for external power supply; the second conversion circuit converts 12V to 5V to power the bridge board circuit, meeting the bridge board's power supply requirements; the third conversion circuit converts 12V to 3.3V to power the main control processing circuit, meeting the main control power supply requirements; and the fourth conversion circuit converts 3.3V to 2.5V to meet the ADC reference voltage requirements, powering the ADC conversion circuit.
[0021] In one embodiment of this utility model, the six-dimensional force sensor further includes a three-beam elastic body, which includes an outer flange, a central platform, three floating beams and three strain beams. The outer flange and the central platform are connected by strain beams, and the outer flange is provided with floating beams. The strain beams are provided with four sides, and strain gauges are provided on each side.
[0022] Compared with the existing technology, the technical effect achieved by adopting this technical solution is as follows: The three-beam elastomer includes an outer flange, a central platform, three floating beams and three strain beams (the three strain beams are at an angle of 120° to each other), and a strain gauge with a resistance of 350Ω is attached to each of the four sides of each strain beam, for a total of 12.
[0023] By adopting the technical solution of this utility model, the following technical effects can be achieved:
[0024] (1) A pre-filter capacitor is connected between the corresponding positive input interface and the negative input interface to filter the analog signal of the bridge board current output, remove noise, and make the ADC input waveform smoother;
[0025] (2) The MAX11254 chip, a 24-bit high-precision analog-to-digital converter, is used to achieve excellent noise performance while maintaining extremely low power consumption; and the accuracy of the six-dimensional force sensor is improved through functions such as oversampling, noise shaping, and digital filtering.
[0026] (3) The three-beam half-bridge of this application only requires 12 strain gauges, which reduces production costs. Attached Figure Description
[0027] Figure 1 A schematic diagram of the analog signal input interface in a six-dimensional force sensor with a three-beam structure provided in Embodiment 1 of this utility model;
[0028] Figure 2 The circuit diagram shows the ADC conversion circuit in a six-dimensional force sensor with a three-beam structure.
[0029] Figure 3 The circuit diagram shows the main control processing circuit in a six-dimensional force sensor with a three-beam structure.
[0030] Figure 4 The circuit diagram shows the power supply circuit of a six-dimensional force sensor with a three-beam structure.
[0031] Figure 5 The schematic diagram shows the RS485 serial communication circuit in a six-dimensional force sensor with a three-beam structure.
[0032] Figure 6 This is a schematic diagram of the bridge circuit in a six-dimensional force sensor with a three-beam structure.
[0033] Figure 7 for Figure 6 PCB diagram of the middle bridge circuit.
[0034] Explanation of reference numerals in the attached figures:
[0035] 110 Positive input interface; 120 Negative input interface; 102 Filter capacitor; 201 Conversion chip; 210 Positive input port; 220 Negative input port; 300 Wheatstone half-bridge; 310 Strain gauge; 320 Resistor; 410 First conversion circuit; 420 Second conversion circuit; 430 Third conversion circuit; 440 Fourth conversion circuit. Detailed Implementation
[0036] To make the above-mentioned objectives, features, and advantages of this utility model more apparent and understandable, the technical solutions in the embodiments of this utility model are clearly and completely described. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.
[0037] Example 1
[0038] See Figure 1 This utility model provides a six-dimensional force sensor with a three-beam structure, combined with Figures 2-7 The six-dimensional force sensor includes: a signal acquisition board circuit, which includes six analog signal input interfaces and an A / D conversion circuit, and the A / D conversion circuit has six ADC ports; the analog signal input interfaces include a positive input interface 110 and a negative input interface 120, and the ADC ports include a positive input port 210 and a negative input port 220; wherein, the positive input port 210 is connected to the positive input interface 110, the negative input port 220 is connected to the negative input interface 120, and a filter capacitor 102 is connected between the positive input interface 110 and the negative input interface 120.
[0039] In one specific embodiment Figure 1 This diagram shows one of the six analog signal input interfaces (the other five are identical in principle, differing only in interface name). AIN-1-AIN+1 serves as one of these analog signal input interfaces (also referred to as channels). AIN+1 is a positive input interface 110, and AIN-1 is a negative input interface 120. Specifically, the ADC's six analog input channels are: AIN-1-AIN+1 as channel 1, AIN-2-AIN+2 as channel 2, AIN-3-AIN+3 as channel 3, AIN-4-AIN+4 as channel 4, AIN-5-AIN+5 as channel 5, and AIN-6-AIN+6 as channel 6. A pre-filter capacitor 102 is connected between the corresponding positive input interface 110 and negative input interface 120 to filter the analog signal output from the bridge board current, removing noise and smoothing the ADC input waveform.
[0040] Furthermore, the ADC conversion circuit uses a 24-bit high-precision analog-to-digital converter chip MAX11254 in its conversion chip 201.
[0041] Specifically, the ADC conversion circuit primarily utilizes the MAX11254 chip, a 24-bit high-precision analog-to-digital converter. This chip is a 6-channel, 24-bit Δ-Σ ADC. Compared to the 201 ADC conversion chip used in other six-dimensional force sensors, the MAX11254 chip achieves excellent noise performance while maintaining extremely low power consumption. Furthermore, the Δ-Σ ADC improves the accuracy of the six-dimensional force sensor through oversampling, noise shaping, and digital filtering. Simultaneously, the MAX11254 chip features 6-channel acquisition capabilities, a sampling frequency up to 12.8kHz, and a built-in 128x adjustable amplifier, offering advantages such as low noise, low power consumption, and high accuracy.
[0042] Furthermore, the six-dimensional force sensor also includes a bridge circuit, which comprises twelve strain gauges 310 and twelve resistors 320, with each pair of strain gauges 310 and each pair of resistors 320 forming a Wheatstone half-bridge 300; wherein, the bridge circuit is used to generate voltage signals.
[0043] Specifically, this application designs a six-dimensional force sensor using a three-beam structure and the Wheatstone half-bridge 300 principle. The three-beam structure is more compact than common crossbeam or parallel elastic body structures. The bridge board circuit includes 12 1kΩ resistors 320 and 12 strain gauges 310. Every two strain gauges 310 and every two resistors 320 form a Wheatstone half-bridge 300, for a total of six Wheatstone half-bridges 300, forming six voltage input channels for acquiring voltage changes in the strain gauges 310. Furthermore, a common crossbeam structure to form a full Wheatstone bridge typically requires 24 strain gauges 310, while the three-beam half-bridge of this application only requires 12 strain gauges 310, reducing production costs.
[0044] Preferred, Figure 7 The PCB diagram for the bridge circuit is shown. Six Wheatstone half-bridges 300 are formed by combining the strain gauges 310 on the beam. When the six-dimensional force sensor is subjected to force, one or more strain gauges 310 will deform according to the force in different directions, and the resistance value will change accordingly. The bridge imbalance will generate voltage changes and output to the six-channel input interface of the ADC.
[0045] Further, see Figure 3 and Figure 5 The signal acquisition board circuit also includes: a main control processing circuit, which is used to process and convert voltage signals into force signals; and an RS485 serial communication circuit, which is used to transmit force signals.
[0046] Specifically, the signal acquisition board circuit is divided into an analog signal input interface, an ADC conversion circuit, a main control processing circuit, and an RS485 serial communication circuit. The bridge board circuit generates a weak voltage signal, which is transmitted to the ADC conversion circuit through the analog signal input interface. Then, the main control processing circuit processes the voltage signal and converts it into a force signal. Finally, the force data (i.e., the force signal) is transmitted through the RS485 serial communication circuit.
[0047] Furthermore, the controller of the main control processing circuit uses the GD32F303CCT6 chip.
[0048] Preferred, see Figure 3 The main control processing circuit uses the GD32F303CCT6 chip to perform data transmission processing to the ADC via the SPI serial port, and uses the GD32F303CCT6 chip to perform voltage signal calculation processing; it uses the USART interface to communicate with RS485.
[0049] Furthermore, the RS485 serial communication circuit uses the SIT3485EUA chip in an MSOP-8 package.
[0050] Specifically, the SIT3485EUA chip, packaged in MSOP-8, makes the structure more compact.
[0051] Preferred, see Figure 5 The RS485 serial communication circuit consists of a transceiver converter SIT3485EUA and a communication interface, which is connected to the host computer via a Remo connector.
[0052] Further, see Figure 4 The signal acquisition board circuit also includes a power supply circuit, which includes a first conversion circuit 410, a second conversion circuit 420, a third conversion circuit 430, and a fourth conversion circuit 440. The first conversion circuit 410 is used for external power supply, the second conversion circuit 420 is used for power supply to the bridge board circuit, the third conversion circuit 430 is used for power supply to the main control processing circuit, and the fourth conversion circuit 440 is used for power supply to the ADC conversion circuit.
[0053] Furthermore, the first conversion circuit 410 uses an HT7463B DC-DC chip; the second conversion circuit 420 and the third conversion circuit 430 use an LM1117 LDO chip; and the fourth conversion circuit 440 uses a REF3025 chip.
[0054] Specifically, the signal acquisition board circuit also includes a power supply circuit, which comprises a first conversion circuit 410, a second conversion circuit 420, a third conversion circuit 430, and a fourth conversion circuit 440. In the entire power supply circuit, analog and digital signals are separated, improving data sampling accuracy and avoiding interference. The first conversion circuit 410 is used for external power supply, converting the external power to 12V using an HT7463B DC-DC chip. The second conversion circuit 420 converts 12V to 5V, powering the bridge board circuit to meet its power supply requirements. The third conversion circuit 430 converts 12V to 3.3V, powering the main control processing circuit to meet its power supply requirements. The fourth conversion circuit 440 converts 3.3V to 2.5V, meeting the ADC reference voltage requirements and powering the ADC conversion circuit. The second conversion circuit 420 and the third conversion circuit 430 are both implemented using an LM1117 LDO; the fourth conversion circuit 440 is implemented using a REF3025 chip.
[0055] Furthermore, the six-dimensional force sensor also includes a three-beam elastomer, which includes an outer flange, a central platform, three floating beams, and three strain beams. The outer flange and the central platform are connected by strain beams, and the outer flange is provided with floating beams. The strain beams have four sides, and each side is provided with a strain gauge 310.
[0056] Specifically, the three-beam elastomer includes an outer flange, a central platform, three floating beams, and three strain beams (the three strain beams are at an angle of 120° to each other). Each strain beam has a strain gauge 310 with a resistance of 350Ω attached to each of its four sides, for a total of 12.
[0057] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and not to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model.
Claims
1. A six-dimensional force sensor employing a three-beam structure, characterized in that, The six-dimensional force sensor includes: The signal acquisition board circuit includes six analog signal input interfaces and an A / D conversion circuit, wherein the A / D conversion circuit is provided with six ADC ports; The analog signal input interface includes a positive input interface (110) and a negative input interface (120), and the ADC port includes a positive input port (210) and a negative input port (220); The positive input port (210) is connected to the positive input interface (110), the negative input port (220) is connected to the negative input interface (120), and a filter capacitor (102) is connected between the positive input interface (110) and the negative input interface (120).
2. The six-dimensional force sensor according to claim 1, characterized in that, The conversion chip (201) of the A / D conversion circuit adopts the MAX11254 chip, a 24-bit high-precision analog-to-digital converter.
3. The six-dimensional force sensor according to claim 1, characterized in that, The six-dimensional force sensor also includes: The bridge board circuit includes twelve strain gauges (310) and twelve resistors (320), and every two strain gauges (310) and every two resistors (320) form a Wheatstone half-bridge (300); The bridge circuit is used to generate voltage signals.
4. The six-dimensional force sensor according to claim 3, characterized in that, The signal acquisition board circuit also includes: The main control processing circuit is used to process and convert the voltage signal into a force signal; The RS485 serial communication circuit is used to transmit the force signal.
5. The six-dimensional force sensor according to claim 4, characterized in that, The controller of the main control processing circuit uses the GD32F303CCT6 chip.
6. The six-dimensional force sensor according to claim 4, characterized in that, The RS485 serial communication circuit uses the SIT3485EUA chip in an MSOP-8 package.
7. The six-dimensional force sensor according to claim 4, characterized in that, The signal acquisition board circuit also includes: The power supply circuit includes a first conversion circuit (410), a second conversion circuit (420), a third conversion circuit (430), and a fourth conversion circuit (440); The first conversion circuit (410) is used for external power supply, the second conversion circuit (420) is used for power supply to the bridge board circuit, the third conversion circuit (430) is used for power supply to the main control processing circuit, and the fourth conversion circuit (440) is used for power supply to the A / D conversion circuit.
8. The six-dimensional force sensor according to claim 7, characterized in that, The first conversion circuit (410) uses an HT7463B DC-DC chip; The second conversion circuit (420) and the third conversion circuit (430) use LM1117 LDO chips; The fourth conversion circuit (440) uses the REF3025 chip.
9. The six-dimensional force sensor according to claim 3, characterized in that, The six-dimensional force sensor also includes: The three-beam elastomer includes an outer flange, a central platform, three floating beams, and three strain beams. The outer flange and the central platform are connected by the strain beams, and the floating beams are provided on the outer flange. The strain beam has four sides, and each side is provided with a strain gauge (310).