A tactile sensor system with integrated signal processing

Abstract

This utility model discloses a tactile sensor system with integrated signal processing, including a multimodal tactile sensor array, a signal conditioning module, an adaptive interference suppression module, a multimodal signal fusion module, a dynamic calibration module, a main control unit, an output interface module, and a power management module. The multimodal sensor array integrates pressure, temperature, and humidity sensitive elements. After amplification and filtering by the signal conditioning module, electromagnetic interference and temperature drift are eliminated by the adaptive interference suppression module. Signal separation and fusion are then achieved by the multimodal signal fusion module. The dynamic calibration module automatically completes calibration. The main control unit coordinates the work of each module, and finally, the processed signal is output through the output interface. This system solves the problems of large environmental interference, multimodal signal crosstalk, and frequent calibration required in existing technologies, improving signal accuracy and environmental adaptability.

Description

Technical Field

[0001] This invention provides a tactile sensor system, and particularly relates to a tactile sensor system with integrated signal processing. Background Technology

[0002] A tactile sensor system is a device that simulates the sensory functions of human skin, converting physical quantities such as mechanical forces (pressure, tension, torque), temperature, and humidity during contact with an object into quantifiable electrical signals. Its core function is to provide tactile feedback information for robots, prosthetics, virtual reality devices, and other applications to interact with their environment. In fields such as industrial grasping, minimally invasive surgery, and rehabilitation medicine, it is a key component for achieving precise operation and safe interaction. For example, in robotic grasping tasks, a tactile sensor system can detect the gripping force on an object in real time, preventing damage due to excessive force or loss due to insufficient force. In minimally invasive surgical instruments, it can sense information such as tissue hardness and temperature, assisting doctors in determining tissue properties and reducing surgical risks.

[0003] Existing tactile sensor systems typically consist of a single type of sensing element (such as resistive, capacitive, or piezoelectric), a simple signal amplification circuit, and an output interface. Resistive systems often use conductive rubber as the sensing material, converting signals by changing the resistance value through external force. However, they lack dedicated interference suppression components, making them susceptible to environmental electromagnetic noise, and the plastic deformation of the conductive material leads to poor signal repeatability. Capacitive systems, while highly sensitive, lack a multimodal fusion processing module in their basic structure, allowing only the detection of a single pressure signal and failing to simultaneously sense temperature, humidity, and other information. Furthermore, dielectric layer aging easily causes baseline drift, requiring frequent manual calibration. Piezoelectric systems rely on the instantaneous charge output of the piezoelectric material, lack a dynamic calibration unit in their basic structure, and cannot achieve stable detection of static forces. Their simple signal processing circuitry makes it difficult to eliminate errors caused by temperature changes. In addition, existing systems often use general-purpose microprocessors for single-mode filtering, lacking dedicated multimodal signal separation and fusion modules. This results in severe crosstalk during the detection of multiple physical quantities, making it difficult to meet the overall sensing accuracy and environmental adaptability requirements of high-precision interactive scenarios. Utility Model Content

[0004] To address the aforementioned issues, this application provides a tactile sensor system with integrated signal processing, which solves problems such as electromagnetic and temperature drift interference, multimodal signal crosstalk, the need for frequent calibration, insufficient accuracy, and poor environmental adaptability.

[0005] To solve the above-mentioned technical problems, this utility model provides the following technical solution: a tactile sensor system with integrated signal processing, comprising: A multimodal tactile sensor array consists of multiple arrayed sensing units, each of which includes a pressure-sensitive element, a temperature-sensitive element, and a humidity-sensitive element. The signal conditioning module is electrically connected to the multimodal tactile sensing array and is used to amplify and perform preliminary filtering on the raw signal output by the sensing array. An adaptive interference suppression module, connected to the signal conditioning module via an SPI bus, is used to eliminate environmental electromagnetic interference and the effects of temperature drift. The multimodal signal fusion module is connected to the adaptive interference suppression module via copper foil wires on the PCB board, and is used to extract and fuse features of pressure, temperature and humidity signals; The dynamic calibration module is connected to the multimodal signal fusion module via an I2C bus and has a built-in calibration module and storage unit. The main control unit is connected to the dynamic calibration module via a UART interface and is used to coordinate the work of each module and process the final signal; The output interface module is connected to the main control unit via a USB interface circuit and is used to output the processed tactile signal.

[0006] Preferably, the signal conditioning module includes: The low-noise instrumentation amplifier uses the INA3221 chip and is connected to the output of the sensing unit via pins 1, 2, and 3. The bandpass filter uses a second-order Butterworth filter circuit, which is composed of capacitor C1 (10nF) and resistor R1 (10kΩ). The input terminal is connected to the output terminal of the instrumentation amplifier through a 0.1mm copper foil wire. The level conversion circuit uses an LMV7219 operational amplifier to adjust the signal voltage range to 0-3.3V, and the output is connected to the input of the adaptive interference suppression module via a pin header.

[0007] Preferably, the adaptive interference suppression module includes: The electromagnetic interference detection unit uses an AD7403 isolation amplifier and is connected to the signal conditioning module via a shielded cable. The adaptive filter uses a TMS320C5509 digital signal processor and is connected to the electromagnetic interference detection unit through the ground plane on the PCB board. The temperature compensation circuit includes a Wheatstone bridge consisting of a PT100 temperature sensor and an operational amplifier, which is connected to the compensation input of the filter through a surface mount resistor R2 (2kΩ).

[0008] Preferably, the multimodal signal fusion module includes: The feature extraction unit uses an STM32H743 microprocessor and transmits data with the adaptive interference suppression module via DMA. The signal separation circuit, consisting of a capacitor array C2-C5 (1μF) and an operational amplifier, is used to separate signal components of different modes. The fusion processing unit uses the FPGA chip EP4CE10 and is connected to the feature extraction unit through a parallel data bus to realize the weighted fusion module of multimodal signals.

[0009] Preferably, the dynamic calibration module includes: The calibration data storage unit uses an AT24C256 EEPROM chip and is connected to the main control unit via an I2C bus. The adaptive calibration module unit is integrated into the ARM Cortex-M4 processor and is connected to the storage unit via an internal data bus; The reference signal generation circuit, composed of the DDS chip AD9833, is connected to the calibration module unit via the SPI interface and is used to generate the calibration reference signal.

[0010] Preferably, the main control unit uses an STM32F407 microcontroller, which internally includes: The data cache unit uses 64KBSRAM and is connected to the processor core via an internal bus; The module coordination unit connects to the control terminals of each module via GPIO pins to achieve timing control; The communication interface unit includes UART, SPI, and I2C controllers, and is connected to the processor core via a peripheral bus.

[0011] Preferably, in the multimodal tactile sensing array, the pressure-sensitive element of each sensing unit adopts an interdigital capacitive sensor, the temperature-sensitive element adopts an NTC thermistor, and the humidity-sensitive element adopts an HS1101 capacitive humidity sensor. The three are encapsulated together with epoxy resin, and the output terminal is connected to the signal conditioning module through a flexible printed circuit.

[0012] Preferably, the adaptive filter employs an LMS adaptive module, implemented through the following circuit: The AD734 multiplier is used for weighted signal processing. Error amplifier OP07 is used to calculate the difference between the desired signal and the actual signal; The coefficient update circuit, consisting of an operational amplifier and an RC network, adjusts the filter coefficients based on the error signal. The circuits described above are connected via surface mount pads with a 0.2mm pitch, forming a closed-loop adaptive adjustment system.

[0013] Preferably, the signal separation circuit employs a blind source separation module, implemented in the following manner: The preprocessing sub-circuit consists of a high-pass filter and a notch filter, used to remove DC components and power frequency interference; The independent component analysis subunit uses a dedicated integrated circuit to implement the FastICA module. The signal reconstruction sub-circuit consists of an adder composed of operational amplifiers, which achieves signal reconstruction by superimposing signals with different weights. The sub-circuits are connected by differential signal lines to reduce noise interference during transmission.

[0014] Preferably, it also includes a power management module, which uses an LT3652 step-down regulator to provide a 3.3V operating voltage and an RT9193-18 regulator to provide a 1.8V core voltage. It is connected to the power input terminals of each module through the power plane. Each power input terminal is equipped with a 0.1μF decoupling capacitor and a resettable fuse.

[0015] One or more technical solutions provided in this application embodiment have at least the following technical effects or advantages compared with the prior art: This device primarily addresses the problems of existing tactile sensor systems, such as high environmental interference, multimodal signal crosstalk, frequent manual calibration, low signal processing accuracy, and poor adaptability. It overcomes the limitations of sensing single physical quantities by integrating pressure, temperature, and humidity-sensitive elements into a multimodal tactile sensor array. The signal conditioning module utilizes a low-noise instrumentation amplifier, bandpass filter, and level conversion circuit to amplify, filter, and adjust the level of the original signal, improving signal quality. The adaptive interference suppression module's electromagnetic interference detection unit, adaptive filter using the LMS algorithm, and temperature compensation circuit effectively eliminate environmental electromagnetic interference and temperature drift. The multimodal signal fusion module's signal separation circuit and fusion processing unit solve the problem of crosstalk between different modes of signals, achieving accurate feature extraction and fusion. The dynamic calibration module's adaptive calibration algorithm unit, reference signal generation circuit, and calibration data storage unit enable automatic dynamic calibration, reducing the frequency of manual calibration. The main control unit coordinates the operation of each module, and the power management module provides stable power. Finally, the output interface module outputs a high-precision processed tactile signal, comprehensively improving the system's anti-interference capability, signal accuracy, and environmental adaptability.

[0016] Other advantages, objectives and features of this invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination or study, or may be taught from the practice of this invention. Attached Figure Description

[0017] Figure 1This is a system structure block diagram of a tactile sensor system with integrated signal processing according to the present invention; Figure 2 This is a data processing timing diagram of a tactile sensor system with integrated signal processing according to the present invention; Figure 3 This is a diagram showing the module interaction of a tactile sensor system with integrated signal processing according to this utility model. Detailed Implementation

[0018] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0019] It should be noted that the terms "vertical," "horizontal," "up," "down," "left," "right," and similar expressions used in this article are for illustrative purposes only and do not represent the only possible implementation.

[0020] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains; the terminology used herein in the description of this invention is for the purpose of describing particular embodiments only and is not intended to limit the invention; the term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0021] like Figure 1 and Figure 2As shown, a tactile sensor system with integrated signal processing includes a multimodal tactile sensing array, which consists of multiple arrayed sensing units. Each sensing unit includes a pressure-sensitive element, a temperature-sensitive element, and a humidity-sensitive element, all three of which are encapsulated together with epoxy resin. The output terminal is connected to a signal conditioning module via a flexible printed circuit. The signal conditioning module is electrically connected to the multimodal tactile sensing array and includes a low-noise instrumentation amplifier, a bandpass filter, and a level conversion circuit, used to amplify and initially filter the raw signal output by the sensing array. An adaptive interference suppression module is connected via an SPI bus. Connected to the signal conditioning module, including an electromagnetic interference detection unit and an adaptive filter (the above circuits are connected via 0.2mm pitch surface mount pads to form a closed-loop adaptive adjustment system), and a temperature compensation circuit, the system is used to eliminate the effects of environmental electromagnetic interference and temperature drift. The system also includes a power management module, which uses an LT3652 step-down regulator to provide a 3.3V operating voltage and an RT9193-18 regulator to provide a 1.8V core voltage. The power management module is connected to the power input terminals of each module via a power plane, and each power input terminal is equipped with a 0.1μF decoupling capacitor and a resettable fuse.

[0022] In this implementation scheme, the triangular distribution and epoxy resin encapsulation design of the multimodal sensing elements ensure simultaneous sensing of multiple physical quantities at the same contact point while reducing mutual interference between elements through physical isolation. The use of flexible printed circuits allows the sensing array to adapt to curved surface installation scenarios, improving the system's flexibility. The signal conditioning module amplifies the weak original signal (mV level) using a low-noise instrumentation amplifier (amplification factor 50-100 times), and uses a bandpass filter (cutoff frequency 0.1-100Hz) to filter out high-frequency noise and DC drift. Then, the signal is uniformly adjusted to 0-3.3V by a level conversion circuit, providing a stable and standard signal input for subsequent processing and solving the problem of weak and fluctuating original signals. The major issues addressed include: In the closed-loop design of the adaptive interference suppression module, the electromagnetic interference detection unit collects environmental interference signals in real time, the adaptive filter dynamically adjusts the filtering coefficient based on the LMS algorithm, and the temperature compensation circuit compensates for the ambient temperature detected by the PT100. This reduces the signal error rate to below 3% in environments with temperature variations of ±20℃ and electromagnetic interference intensity ≤1V / m, effectively overcoming the shortcomings of poor anti-interference capabilities in existing systems. The power management module, through dual voltage output and power plane design, ensures stable power supply to each module (3.3V for analog circuits and 1.8V for digital circuits). Decoupling capacitors and self-resetting fuses suppress power supply noise and prevent overcurrent damage, respectively, improving the system's operational stability and reliability. From an innovation and beneficial perspective, the synergistic effect of each structure enables the system to simultaneously possess multimodal sensing capabilities, strong anti-interference capabilities, and stable operating performance. Compared to single-modal sensors, it can more comprehensively reflect contact environment information. Compared to systems without adaptive processing, signal accuracy is improved by more than 40% in complex environments, and frequent maintenance is unnecessary, significantly expanding the application scenarios of tactile sensors.

[0023] like Figure 2 and Figure 3 As shown, a tactile sensor system with integrated signal processing includes a multimodal signal fusion module, which is connected to an adaptive interference suppression module via copper foil wires on a PCB board. This module includes a feature extraction unit, a signal separation circuit, an independent component analysis sub-unit, a signal reconstruction sub-circuit (connected via differential signal lines), and a fusion processing unit for feature extraction and fusion of pressure, temperature, and humidity signals. A dynamic calibration module is connected to the multimodal signal fusion module via an I2C bus and includes a calibration data storage unit, an adaptive calibration algorithm unit, a reference signal generation circuit, and a built-in calibration algorithm and storage unit. A main control unit is connected to the dynamic calibration module via a UART interface and uses an STM32F407 microcontroller. This microcontroller internally includes a data buffer unit, a module coordination unit, and a communication interface unit, used to coordinate the operation of each module and process the final signal. An output interface module is connected to the main control unit via a USB interface circuit for outputting the processed tactile signal.

[0024] In this implementation scheme, the multimodal signal fusion module adopts a "microprocessor + FPGA" architecture. The feature extraction unit achieves seamless data transmission with the interference suppression module via DMA (1Mbps transmission rate). The differential signal line design of the signal separation circuit enables noise attenuation of over 20dB during transmission. The FastICA algorithm dedicated integrated circuit of the independent component analysis subunit can complete single-channel signal separation within 50μs. The FPGA of the fusion processing unit achieves real-time fusion of multimodal signals (processing delay <100μs) through a parallel weighted fusion algorithm (dynamically adjustable weight coefficients), solving the feature confusion problem caused by multimodal signal crosstalk. The dynamic calibration module generates an adjustable reference signal of 0-3.3V (accuracy ±0.5mV) through a reference signal generation circuit (AD9833). Combined with the adaptive calibration algorithm unit, it automatically triggers calibration once per hour (calibration time <2s). The calibration data is stored in real time to EEPROM (erase / write cycles >100,000 times), maintaining the long-term accuracy of the system without manual intervention, overcoming the shortcomings of traditional sensors that require weekly manual calibration. The main control unit achieves synchronized operation of each module through GPIO timing control (trigger pulse width 100ns) of the module coordination unit. A 64KBSRAM data cache unit can buffer 1024 sets of multimodal data, preventing data loss due to overflow. The multi-protocol support of the communication interface unit (UART baud rate 115200bps, SPI clock 10MHz) ensures compatibility of data interaction between modules. The CH340 chip in the output interface module performs USB and UART signal conversion, achieving a data transmission rate of 2Mbps, meeting the real-time tactile signal output requirements. In terms of innovation and beneficial effects, this combined design improves the separation accuracy of multimodal signals to over 95% (crosstalk rejection ratio >30dB), dynamic calibration keeps the long-term system drift within ±1%FS, and the coordinated scheduling of the main control unit ensures an overall system response time of <500μs. Compared to existing technologies, it achieves breakthroughs in multimodal perception integrity, environmental adaptability, and real-time performance, making it particularly suitable for scenarios with stringent requirements for tactile signal quality, such as high-precision robot grasping and minimally invasive surgery.

[0025] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be determined by the claims.

Claims

1. A tactile sensor system with integrated signal processing, characterized by The application relates to a multi-modal tactile sensor array, a signal conditioning module, an adaptive interference suppression module, a multi-modal signal fusion module, a dynamic calibration module, a main control unit and an output interface module. The signal conditioning module comprises a low-noise instrument amplifier, a band-pass filter and a level conversion circuit. The adaptive interference suppression module comprises an electromagnetic interference detection unit, an adaptive filter and a temperature compensation circuit. The multi-modal signal fusion module comprises a feature extraction unit, a signal separation circuit and a fusion processing unit. The dynamic calibration module comprises a calibration data storage unit, an adaptive calibration module unit and a reference signal generation circuit. The main control unit is connected with the dynamic calibration module through a UART interface. The output interface module is connected with the main control unit through a USB interface circuit. ​ 2. The system of claim 1, wherein, ​ ​ ​ ​ 3. The system of claim 1, wherein, ​ ​ ​ ​ 4. The system of claim 1, wherein, ​ ​ ​ ​ 5. The system of claim 1, wherein, ​ ​ ​ ​ 6. The system of claim 1, wherein, The main control unit uses an STM32F407 microcontroller, which internally includes: The data cache unit uses 64KBSRAM and is connected to the processor core via an internal bus; The module coordination unit connects to the control terminals of each module via GPIO pins to achieve timing control; The communication interface unit includes UART, SPI, and I2C controllers, and is connected to the processor core via a peripheral bus.

7. The system of claim 1, wherein, In the multimodal tactile sensing array, the pressure-sensitive element of each sensing unit adopts an interdigital capacitive sensor, the temperature-sensitive element adopts an NTC thermistor, and the humidity-sensitive element adopts an HS1101 capacitive humidity sensor. The three are encapsulated together with epoxy resin, and the output end is connected to the signal conditioning module through a flexible printed circuit.

8. The system of claim 3, wherein, The adaptive filter employs an LMS adaptive module, implemented through the following circuitry: The AD734 multiplier is used for weighted signal processing. Error amplifier OP07 is used to calculate the difference between the desired signal and the actual signal; The coefficient update circuit, consisting of an operational amplifier and an RC network, adjusts the filter coefficients based on the error signal. The circuits described above are connected via surface mount pads with a 0.2mm pitch, forming a closed-loop adaptive adjustment system.

9. The system of claim 4, wherein, The signal separation circuit employs a blind source separation module, implemented in the following manner: The preprocessing sub-circuit consists of a high-pass filter and a notch filter, used to remove DC components and power frequency interference; The independent component analysis subunit uses a dedicated integrated circuit to implement the FastICA module. The signal reconstruction sub-circuit consists of an adder composed of operational amplifiers, which achieves signal reconstruction by superimposing signals with different weights. The sub-circuits are connected by differential signal lines to reduce noise interference during transmission.

10. The system of claim 1, wherein, It also includes a power management module, which uses an LT3652 step-down regulator to provide a 3.3V operating voltage and an RT9193-18 regulator to provide a 1.8V core voltage. It is connected to the power input terminals of each module through the power plane. Each power input terminal is equipped with a 0.1μF decoupling capacitor and a self-resetting fuse.

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