Robot fingertip touch sensor structure
The robot fingertip tactile sensor structure, which combines Hall effect chips with magnets, solves the problems of high hysteresis and strong temperature dependence of existing sensors. It achieves high-sensitivity multi-dimensional spatial perception and rapid response, and has dustproof and waterproof capabilities. The structure is simple and the cost is controllable.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-09
- Publication Date
- 2026-04-07
AI Technical Summary
Existing robotic fingertip tactile sensors suffer from problems such as high hysteresis, strong temperature dependence, insufficient multidimensional perception capabilities, and high cost, making it difficult to achieve high sensitivity and multidimensional spatial perception.
The design combines a Hall chip with a magnet, which identifies the point of force and the magnitude of force by changing the magnetic field. The magnet and Hall chip are used to convert the force into an electrical signal, and combined with potting encapsulation technology, it realizes three-dimensional spatial perception and rapid response.
It achieves high sensitivity and fast response in multi-dimensional spatial perception. The product's accuracy is not affected by ambient temperature. It is dustproof and waterproof, and has a simple structure and controllable cost.
Smart Images
Figure CN224095295U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to a sensor, and more particularly to a structure for a robot fingertip tactile sensor. Background Technology
[0002] In simple terms, a robot's fingertip tactile sensor is a sensor installed on the fingertip of a robot to simulate the tactile function of a human finger. Just as human fingers can perceive the shape, texture, hardness, and applied force of objects through touch, the role of a robot's fingertip tactile sensor is to enable robots to possess similar perceptual abilities. It acts like the robot's "tactile nerves," converting physical signals into electrical signals, allowing the robot to "feel" external stimuli and react accordingly.
[0003] Existing robotic fingertip tactile sensors include the following types: (1) Piezoresistive sensors that detect pressure by changing the resistivity of materials under force, but these sensors have high hysteresis and high temperature dependence, can only measure normal force (perpendicular to the contact surface), and have weak shear force and sliding sensing capabilities; (2) Piezoelectric tactile sensors that are based on the piezoelectric effect, where external force causes a change in the polarization state of the piezoelectric material, generating a charge signal proportional to the external force, but these sensors are suitable for intermittent signals, difficult to measure static force, have high material processing requirements, and are costly; (3) Capacitive tactile sensors that convert capacitance changes into electrical signals by changing the distance between plates or the dielectric constant, but their accuracy decreases as their physical size increases, can only measure uniaxial pressure, and are easily affected by parasitic capacitance; (4) Optical tactile sensors that utilize the reflection, refraction, or scattering characteristics of light to achieve non-contact high-precision measurement through optical signal conversion, but their algorithm complexity is high, and they have strict requirements on the shape and size of the sensor. Summary of the Invention
[0004] This invention addresses the problems of the aforementioned sensors by providing a robot fingertip tactile sensor structure that is simple in structure, small in size, highly sensitive, has a fast response, possesses multi-dimensional spatial perception capabilities, can continuously output signals, has low hysteresis, and whose product accuracy is unaffected by ambient temperature.
[0005] The above-mentioned technical problem of this utility model is solved by the following technical solution:
[0006] A robotic fingertip tactile sensor structure includes a PCBA board with at least one Hall effect chip mounted on it. The PCBA board is mounted on a housing via a positioning structure. An adhesive inlet is located at the bottom of the housing. A first-layer coated main body is positioned above the PCBA board, with positioning grooves on both sides. Magnet mounting holes are formed on the main body, and magnets are installed within these holes. A second-layer coated top cover is located outside the main body with the magnets. When a force F is applied to the sensor surface, the surface undergoes elastic deformation, causing the magnets inside the sensor to shift. Using this principle, a matrix of force points can be arranged on the tactile sensor surface according to spatial coordinates, and the magnitude of the force and the change in magnetic field strength at each force point can be calibrated online. After calibrating the force values of all force point matrices, when the surface of the tactile sensor is deformed, the chip can identify the area under force and the magnitude of the force by observing the change in magnetic field strength. By changing the position of the magnets, the magnetic field changes, and the Hall effect chip converts the magnetic signal into an electrical signal, resulting in high sensitivity and fast response. The PCBA board is first installed onto the housing, and then the main body is formed by a first-stage film coating through the glue inlet. After the magnet is installed onto the main body, the magnet is suspended in the silicone body through a second film coating. The magnet works with the chip to quickly sense and improve product accuracy.
[0007] Preferably, the Hall chip is a 3D Hall chip, and there are three Hall chips arranged in a triangle on the PCBA board. Considering the size limitations of the robot hand, the Hall chip is attached to the skin side closest to the sensor, reducing the distance between the chip and the magnet, allowing the chip to detect a stronger magnetic field.
[0008] Preferably, the magnet comprises three magnet groups in the X, Y, and Z directions, which are respectively mounted on the three sides of the main body in the three directions. This enables three-axis multi-dimensional spatial perception capability, continuous signal output, and high precision.
[0009] Preferably, the positioning structure includes mutually cooperating positioning posts and positioning holes, which are located on the outer casing and the PCBA board, respectively, with the positioning posts and positioning holes having an interference fit. This small interference fit allows the PCBA board and the outer casing to have an initial relative position determined, resulting in a simple structure.
[0010] Preferably, the positioning grooves are in two sets, with two grooves in each set, and two positioning grooves on each side of the main body. During injection, the positioning grooves correspond to the pillars inside the mold, which hold the PCBA board in place, ensuring that the relative position of the PCBA board and the outer shell does not shift due to injection pressure, thus achieving proper positioning of the PCBA board. The two grooves on each side form four positioning points, resulting in good positioning performance.
[0011] Preferably, the PCBA board is externally connected to an FPC or a wiring harness. Because robotic arms frequently bend, the signal transmission medium needs to be flexible and resistant to repeated bending. If the tactile sensor application environment does not involve repeated bending, a wiring harness can be used instead of the FPC to reduce product costs.
[0012] Preferably, the PCBA board is located inside the main body, which is made of liquid silicone. After the product is coated, the PCBA is encapsulated inside the silicone, giving the sensor a certain degree of dust and water resistance.
[0013] Therefore, the robot fingertip tactile sensor structure of this utility model has the following advantages: it achieves high sensitivity and fast response by combining magnets and Hall chips; at the same time, it distributes magnets in three dimensions to achieve multi-dimensional spatial perception capabilities and improve product accuracy; it uses potting to achieve three-dimensional distribution of magnets and encapsulates the PCBA board inside, giving the sensor a certain degree of dust and water resistance. Attached Figure Description
[0014] Figure 1 This is a 3D diagram of the structure of a robot's fingertip tactile sensor.
[0015] Figure 2 It is a 3D view with the top cover removed;
[0016] Figure 3 yes Figure 1 An explosion diagram;
[0017] Figure 4 yes Figure 1 A sectional view;
[0018] Figure 5 yes Figure 1 A three-dimensional view of the inner shell. Detailed Implementation
[0019] The technical solution of the utility model will be further described in detail below through embodiments and in conjunction with the accompanying drawings.
[0020] Example:
[0021] like Figure 1 As shown, a robotic fingertip tactile sensor structure includes a housing 2, the shape of which is similar to the shape of a human finger, resembling a rectangle (e.g., ...). Figure 5 (As shown). An adhesive inlet 12 is provided in the center of the outer shell 2. Positioning posts 10 are formed at two diagonal corners on the inner bottom surface of the outer shell 2. Positioning holes 8 are formed on the PCBA board 11. Three 3D Hall chips 9 are attached to the PCBA board 11 near the sensor skin side. The 3D Hall chips 9 are divided into two rows. There is one in the first row located at the fingertip, and two in the second row.
[0022] like Figure 2 and 3 As shown in Figure 4, the PCBA board 11 is mounted on the housing 2 through a small interference fit between the positioning hole 8 and the positioning post 10. Then, liquid silicone is injected from the glue inlet 12 at the bottom of the housing 2 to form the main body 4 in a single coating process. During the molding process, in order to position the PCBA board, four protrusions in the mold abut against the PCBA board at the positioning groove 6 of the main body. The liquid silicone main body 4 completely encapsulates the PCBA board 11, giving the sensor a certain degree of dust and water resistance.
[0023] The formed main body 4 is also provided with multiple magnet mounting holes 7. The magnet mounting holes 7 are distributed on the upper surface, front and rear sides and left side of the main body. The wiring 3 of the PCBA board is led out from the right side of the main body. The wiring 3 of the PCBA board can be FPC or wire harness, depending on different usage requirements.
[0024] Magnet 5 is glued to magnet mounting hole 7. After magnet 5 is fully fixed, we then perform a second film coating to form top cover 1 on this semi-finished product. Through this process, the magnet is embedded inside the sensor. Top cover 1 and outer shell 2 form the complete external shape of the sensor structure. We can drill corresponding bolt holes and positioning according to the installation space requirements of the matching robot for assembly in the palm area of the robot hand.
[0025] The specific embodiments described herein are merely illustrative examples of the present invention. Those skilled in the art to which this invention pertains may make various modifications or additions to the described specific embodiments or use similar methods to replace them, without departing from the spirit of this invention or exceeding the scope defined by the appended claims.
Claims
1. A robot fingertip tactile sensor structure, characterized in that: The device includes a PCBA board, on which at least one Hall effect chip is mounted. The PCBA board is mounted on a housing via a positioning structure. An adhesive inlet is provided at the bottom of the housing. A main body with a first-stage film coating is provided above the PCBA board. Positioning grooves are provided on both sides of the main body. Magnet mounting holes are formed on the main body. Magnets are installed in the magnet mounting holes. A top cover with a second-stage film coating is provided outside the main body with the magnets installed.
2. The structure of a robot fingertip tactile sensor according to claim 1, characterized in that: The Hall chip is a 3D Hall chip, and there are three Hall chips arranged in a triangle on the PCBA board.
3. A robot fingertip tactile sensor structure according to claim 1 or 2, characterized in that: The magnets include three magnet groups in the X, Y and Z directions, and the three magnet groups are respectively installed on the three sides of the main body in the three directions.
4. A robot fingertip tactile sensor structure according to claim 1 or 2, characterized in that: The positioning structure includes a positioning post and a positioning hole that cooperate with each other. The positioning post and the positioning hole are located on the outer shell and the PCBA board, respectively, and the positioning post and the positioning hole are interference fit.
5. A robot fingertip tactile sensor structure according to claim 1 or 2, characterized in that: The positioning grooves are in two sets, with two positioning grooves in each set, and two positioning grooves on each side of the main body.
6. The structure of a robot fingertip tactile sensor according to claim 1 or 2, characterized in that: The PCBA board is externally connected to an FPC or wire harness.
7. The structure of a robot fingertip tactile sensor according to claim 1 or 2, characterized in that: The PCBA board is located inside the main body, which is made of liquid silicone.