Pressure measurement assembly for sensing force acting on end portion of robot nail, and bionic finger

Abstract

A pressure measurement assembly for sensing a force acting on an end portion of a robot nail, and a bionic finger, said pressure measurement assembly comprising an end knuckle (1), an artificial nail (2), and a processing module. The artificial nail (2) is mounted on the end knuckle (1), the rigidity of the artificial nail (2) is set above Mohs 2, a nail front edge (21) extends outwards beyond a fingertip of the knuckle, and an end portion of the nail front edge (21) serves as a first force acting area (21a) to be in physical contact with an external object. The artificial nail (2) is slidably connected to the end knuckle (1) in a direction along the fingertip. Under a force acting on the first force acting area (21a), the artificial nail (2) slides toward the knuckle. At least one first pressure sensor (212) capable of autonomous elastic recovery after being pressed is fixed on the sliding path for measuring a first one-dimensional force. The size of the outer diameter of the pressure sensor (212) is configured to be at most 100% of the maximum size of the artificial nail (2). The processing module is coupled to the first pressure sensor (212) for outputting, on the basis of the first one-dimensional force, the applied force acting on the first force acting area (21a).

Description

A pressure detection component for sensing the force applied to the tip of a robot's fingernail, a bionic finger Technical Field

[0001] This invention relates to home service robots, and more particularly to a pressure detection component for sensing the force applied to the tip of a robot's fingernail, and a bionic finger. Background Technology

[0002] Home service robots are humanoid robotic devices capable of performing various service tasks in home or similar environments, and the market demand is becoming increasingly fierce. Compared to traditional robotic arms that serve industrial manufacturing, home service robots tend to act as life assistants or butlers in the home environment, providing daily life services.

[0003] Fingernails, as an important component of human fingers, help people perform various tasks such as scratching, picking, poking, and flicking. For home service robots, the robot's body surface is typically covered with flexible electronic skin to provide tactile input. Therefore, equipping the fingers with artificial fingernails would be more conducive to performing these actions. Furthermore, the fingertips formed by the artificial fingernails and flexible electronic skin are also beneficial for grasping small objects, such as needles, screws in electronic products, and phone cards. After equipping the fingers of home service robots with artificial fingernails, how to measure the force exerted on the fingernails becomes a design challenge that needs to be solved. The machine system needs to be able to sense the force of scratching, flicking, and poking to avoid causing injury to the object being served during home service tasks.

[0004] Six-dimensional force sensors, which simultaneously detect three force components and three torque components, are currently mainly used in industrial robotic arms or humanoid robots to achieve six-dimensional force sensing at the shoulder, elbow, and / or wrist joints. These joints allow for three degrees of freedom of movement and provide sufficient space to house six-dimensional force sensors ranging in size from tens to thousands of millimeters. The size of six-dimensional force sensors varies depending on the brand and model; for example, the American ATI miniature six-dimensional force sensor measures Φ1714.5 (mm), while the German Me-System three-dimensional / six-dimensional force sensor has a housing size of 29mm x 27mm. However, using six-dimensional force sensors to detect nail mechanics is unsuitable for measuring the force and torque of a fingernail. One problem is the lack of sufficient space between the nail and finger; more importantly, there is the cost issue. Currently, the purchase price of a six-dimensional force sensor is approximately 100,000 RMB per unit, making the design difficult for the market to accept.

[0005] Patent document JP2023073764A discloses a robot system that notes the importance of humanoid robots setting up fingernails for application services and the task of measuring the force on the fingernails. The document proposes to use a six-dimensional force sensor to measure the force on the fingernails. For the reasons mentioned above, it is difficult to implement a six-dimensional force sensor in terms of fingernail installation and cost control, so there is currently no commercial promotion.

[0006] Therefore, how to measure the force on the fingernails of home service robots in a low-cost and feasible manner has become an issue to be addressed. Summary of the Invention

[0007] For a poking motion, the tip of the fingernail is subjected to a radial force, and the magnitude of the force reacts to the object in contact. Therefore, one of the objectives of this invention is to realize the sensing of the force on the tip of the robot's fingernail.

[0008] To address this, a pressure detection component for sensing the force applied to the tip of a robotic fingernail is provided, comprising a distal phalanx, an artificial fingernail, and a processing module. The artificial fingernail is mounted on the distal phalanx, with a stiffness set at 2 Mohs or higher. The leading edge of the fingernail extends outward from the fingertip of the phalanx, and the tip of the leading edge serves as the first force-bearing area for physical contact with an external object. The artificial fingernail slides along the fingertip direction to the distal phalanx, and under the force applied to the first force-bearing area, it slides towards the phalanx. At least one first pressure sensor with autonomous elastic recovery after being pressed is fixed on the sliding path to detect the first unidimensional force. The outer diameter of the pressure sensor is configured to be at most 100% of the maximum size of the fingernail. The processing module is coupled to the first pressure sensor and outputs the force applied to the first force-bearing area based on the first unidimensional force. For example, when performing a poking action, the force is transmitted radially along the fingernail. The first pressure sensor is located on the positive side of the sliding path, and the elasticity of the pressure sensor allows the fingernail to slide to a certain extent while detecting the first unidimensional force. The value of the first unidimensional force is not significantly different from the force applied to the fingernail. The processing module outputs the force applied to the first force-bearing area based on the first unidimensional force.

[0009] As an improvement, the protrusion on the inner wall of the distal phalanx cooperates with the groove on the side wall of the artificial nail to form a locking limit for the sliding stroke.

[0010] As another improvement, the bottom and / or top of the leading edge of the nail serves as a second force-bearing area in contact with an external object; the distal phalanx is provided with a first fulcrum acting on the artificial nail. Under the action of the nail's normal force in the second force-bearing area, the artificial nail is supported by the first fulcrum and generates a first rotational displacement. At least one second pressure sensor with autonomous elastic recovery after being pressed is fixed on the path of the first rotational displacement to detect the second unidimensional force; the processing module is coupled to the second pressure sensor and is used to output the normal force and / or torque acting on the second force-bearing area based on the second unidimensional force and the corresponding lever arm.

[0011] Furthermore, the distance from the tip of the nail to the outward-pointing edge should be 5%-50% of the nail body.

[0012] Furthermore, the first fulcrum is supported on the upper surface between the nail root and the leading edge. The bottom of the leading edge of the nail serves as the second force-bearing area to contact an external object and generate a positive normal force. The second pressure sensor is fixed in the space below the nail root. Furthermore, the inner wall of the distal phalanx and the second pressure sensor together form a clamping mechanism for the artificial nail. There is a gap between the artificial nail and the inner wall of the distal phalanx and / or the second pressure sensor, allowing the artificial nail to slide. Furthermore, the leading edge of the nail slopes downwards, creating an offset from the direction of extension. Furthermore, the artificial nail protrudes from the upper surface of the distal phalanx as a third force-bearing area in contact with an external object. At least one third pressure sensor with autonomous elastic recovery after being pressed is arranged below the third force-bearing area of ​​the nail to support it. The third pressure sensor is used to detect a third unidimensional force. The processing module is coupled to the third pressure sensor and is used to output the negative normal force acting on the third force-bearing area based on the third unidimensional force.

[0013] As another improvement, the pressure detection component includes a capacitance-to-digital converter circuit and multiple sensing electrodes; the multiple sensing electrodes form an electrode array for sensing the approach of an object to the force-bearing area and / or the contact status on the force-bearing area; the capacitance-to-digital converter circuit couples each sensing electrode in the electrode array to obtain self-capacitance and / or mutual capacitance; the processing module couples the capacitance-to-digital converter circuit to output an electrical signal sensing the approach of an external object and / or output the position of the force point and / or the force-bearing area acting on the force-bearing area based on the self-capacitance and / or mutual capacitance.

[0014] As another improvement, the artificial nail includes a body, with the nail tip movably and retractably disposed at the front end of the body; the pressure detection component is provided with an actuation device that drives the nail tip to extend or retract from the body.

[0015] As another improvement, the pressure sensor is configured as a single-dimensional force sensor; or, the pressure sensor includes a flexible body with an upper electrode inside, the upper electrode being a curved elastic electrode, and one or more lower electrodes below the upper electrode. An insulating layer is provided on the bottom surface of the upper electrode and / or the top surface of the lower electrode. The projection of the upper electrode relative to the lower electrode covers at least a portion of the area of ​​the lower electrode. When the flexible body is deformed by an external force, the upper electrode changes the indirect contact area with the lower electrode. The pressure detection component includes a capacitance-to-digital conversion circuit, which couples each upper electrode to the lower electrode, and a processing module couples the capacitance-to-digital conversion circuit.

[0016] A bionic finger is also provided, including the aforementioned pressure detection component. Attached Figure Description

[0017] Figure 1 shows the structural composition of the distal phalanx of the bionic finger;

[0018] Figure 2 shows the internal structure of the distal phalanx of the bionic finger;

[0019] Figure 3 shows the arrangement of the first pressure sensor;

[0020] Figure 4 illustrates the force exerted on the fingernail during the stabbing action;

[0021] Figure 5a shows the structure of a capacitive single-dimensional force sensor;

[0022] Figure 5b shows the structure of a capacitive three-dimensional force sensor;

[0023] Figure 6 illustrates the force exerted on the fingernails when performing actions such as scratching or picking.

[0024] Figure 7a shows the first position setting of the first fulcrum and the sensor;

[0025] Figure 7b shows a second way of setting the position of the first fulcrum and the sensor;

[0026] Figure 7c shows a third way of setting the position of the first fulcrum and the sensor;

[0027] Figure 7d shows the fourth position setting method for the first fulcrum and the sensor;

[0028] Figure 8 shows a nail structure with the leading edge sloping downwards;

[0029] Figure 9a shows a schematic diagram of the force on the upper surface of the nail when performing a snapping or pressing action;

[0030] Figure 9b shows the arrangement of the third pressure sensor; and

[0031] Figure 10 shows the arrangement of the electrode array in the third force-sensing region. Detailed Implementation

[0032] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0033] Figure 1 shows the structural composition of the distal phalanx of the bionic finger. The phalanx is designed to resemble human skin, with its outer surface covered by flexible electronic skin to achieve tactile perception. An artificial fingernail 2 is installed at the tip of the distal phalanx 1. The internal structure of the phalanx houses a processing module, circuitry, and other components, forming an independent finger module. The distal phalanx 1, the artificial fingernail 2, and the processing module together constitute a pressure detection component for sensing the force of the fingernail in the robot.

[0034] Human fingernails are connected to flesh and blood tissue and are relatively flexible. To provide a wider range of uses than human fingernails and to reduce errors in force measurement, as shown in Figure 2, the stiffness of the artificial fingernail 2 is set to 2 Mohs or higher. The leading edge 21 of the fingernail extends outward from the fingertip, and the end of the leading edge 21 serves as the first force-bearing area 21a to make physical contact with external objects. The artificial fingernail 2 slides along the fingertip direction to the distal phalanx 1. When performing a poking action, the artificial fingernail slides towards the phalanx under the force of the first force-bearing area 21a, as shown in Figure 3. At least one first pressure sensor 212 with autonomous elastic recovery after pressing is fixed on the sliding path to detect the first unidimensional force F1'.

[0035] The artificial nail 2 can slide in various ways on the distal phalanx 1. As an example, Figure 4 shows a structure in which the nail root is radially inserted into a groove in the phalanx. The distal phalanx 1 has a rectangular groove 300 to accommodate the nail root. The opening of the groove 300 faces the nail direction, and the nail root is horizontally inserted into the groove 300 with a small gap to allow for movable insertion and removal. Furthermore, the top sidewall of the artificial nail 2 slides in contact with the inner wall of the distal phalanx 1. To prevent the nail from sliding outwards and detaching, a protrusion 11 is formed on the inner wall of the distal phalanx 1. The hemispherical protrusion 11 is embedded in a groove 213 on the top sidewall of the nail root. The groove 213 is slightly larger than the protrusion 11, allowing the protrusion 11 to slide radially within the groove, and also forming a locking limit for the sliding stroke. Furthermore, the protrusion 11 can be strip-shaped or hemispherical, with its cross-section along the sliding direction forming an arc surface, which helps reduce friction while not hindering the rotation of the nail around the first fulcrum described below.

[0036] The outer diameter of the pressure sensor is configured to be at most 100% of the maximum size of the fingernail to accommodate the robotic end segment and the artificial fingernail while accommodating force detection. The implementation of a pressure sensor meeting this size can be varied. One example is functional tailoring, using a single-dimensional force sensor to meet the size requirements. Single-dimensional force sensors, such as piezoelectric force sensors or parallel-plate capacitive force sensors, measure the force in only one direction, allowing for a sufficiently small size while controlling costs. Another embodiment can adopt the force sensor structure shown in Figures 5a and 5b, where the pressure sensor includes a flexible body 500 that bulges upwards to increase force absorption. The part is provided with an upper electrode 501, which is a curved elastic electrode that protrudes downward from the inside of the flexible body 500, forming a shape similar to a sphere or ellipse. Below the upper electrode 502, a lower electrode 502 is provided, as shown in Figure 5a, to form a normal one-dimensional force detection, or multiple lower electrodes 502 are provided, as shown in Figure 5b, which allow tangential force measurement without increasing the volume in addition to normal force measurement. Optimally, as shown in Figure 5b, four electrodes 5021, 5022, 5023, and 5024 are provided to achieve three-dimensional force detection. In Figures 5a and 5b, an insulating layer is provided on the bottom surface of the upper electrode 501 and / or the top surface of the lower electrode 502. The insulating layer acts as the dielectric material between the upper and lower electrodes, providing an increase in dielectric constant of more than an order of magnitude compared to air. The projection of the upper electrode 501 relative to the lower electrode 502 at least covers part of the area of ​​the lower electrode 502. When the flexible body 500 is deformed by external force, the upper electrode 501 changes the indirect contact area with the lower electrode 502. For example, pressing down results in an increase in the contact area, and removing the external force results in a decrease in the contact area due to the elastic recovery of the flexible body. Because of the small spacing (the upper and lower electrodes contact each other through the insulating layer), high dielectric constant (the material of the insulating layer itself), and large change in contact area (the change in area from point contact to surface contact is huge), the sensor has a very high force detection sensitivity, comparable to the resolution of a human fingertip. At the same time, the size can be made relatively small to meet the requirements for the placement and installation between the distal phalanx and the artificial nail. The pressure detection component uses a capacitance-to-digital converter (CDC) circuit to acquire the capacitance shown in Figures 5a and 5b. CDCs, such as DAI7142 and ADI7147, employ a Δ-Σ modulation method to directly convert the measured capacitance value into a digital value by repeatedly charging and discharging the measured capacitor and comparing it with a reference capacitance (see: US Patent Number: 5,134,401). This can improve the measurement sensitivity of capacitance to the 1ff level and easily meet the capacitance measurement sensitivity requirements of the measurement system. It also has the characteristic of being immune to stray capacitance. In particular, these chips are designed with multiple channels. When connected, the capacitance-to-digital converter circuit couples each upper electrode to the lower electrode, and the processing module couples the capacitance-to-digital converter circuit.

[0037] When performing a stabbing action, the force is transmitted radially from left to right. As shown in Figure 4, the first pressure sensor 212 is located in the positive bearing of the sliding path. The elasticity of the pressure sensor allows the nail to slide to a certain extent while detecting the first unidimensional force F1'. The value of the first unidimensional force F1' is not much different from the force F1 on the nail. The processing module is coupled to the first pressure sensor 212 and outputs the force on the first force area 21a according to F1'.

[0038] The robot's distal phalanx has only one degree of freedom in one direction. The distal phalanx forms a flexing motion around its end joint, with the flexion motion in the same direction as the nail's normal. For actions such as scratching or picking, the nail experiences a force along its normal direction. The magnitude of this force reacts to the object in contact, and the nail rotates simultaneously. Torque is generally used to evaluate the interaction of the object's rotation. Based on this, as an improvement, Figure 6 shows a schematic diagram of the forces acting on the nail during a scratching or picking motion. The bottom and / or top of the nail's leading edge serve as a second force-bearing area 22a in contact with an external object. The distal phalanx is provided with a first fulcrum 221 acting on the artificial nail. During a scratching or picking motion, under the normal force of the nail in the second force-bearing area 22a, the artificial nail, supported by the first fulcrum 221, generates a first rotational displacement 222. At least one second pressure sensor 223, which has autonomous elastic recovery after being pressed, is fixed on the path of the first rotational displacement 222 to detect the second unidimensional force.

[0039] Figures 7a to 7d show the setup of the lever arm and sensor 223 when the first fulcrum 221 is in different positions. In Figures 7a and 7c, the power arm L1 from the second force zone to the first fulcrum and the resistance arm L2 from the second pressure sensor to the first fulcrum are located on both sides or the same side of the first fulcrum 221, respectively. The second pressure sensor 223 is placed above or below the artificial nail. Figures 7b and 7d show the position of the first fulcrum 221 and the setup of the lever arm when the normal force of the action, such as the spring or press, is applied from top to bottom. For the functional requirement of measuring both the downward and upward normal forces, the second pressure sensor 223 can have multiple sensors placed on the upper and lower sides of the artificial nail.

[0040] The second force-bearing zone 22a rotates around the first fulcrum 221 under the normal force F2. Since the force is amplified by the greater force arm L1 than the resistance arm L2, the second pressure sensor 223 detects the second single-dimensional force F3 generated by the fingernail's rotation. Given that L1 and L2 are known, the force on the fingernail F2 * lever arm L1 = the force exerted by the fingernail on the pressure sensor F3 * lever arm L2. Based on the second single-dimensional force and its corresponding lever arm, the processing module outputs the normal force and / or torque acting on the second force-bearing zone. Because the distal phalanx has only one degree of freedom in the bending direction, using a force sensor on the rotational displacement in conjunction with a fingernail anthropomorphically extending from the fingernail allows for the measurement of both the magnitude of the force and the torque, satisfying the requirements for measuring the fingernail's normal force and torque.

[0041] Furthermore, in Figure 4, the first fulcrum 221 is supported on the upper surface between the nail root and the leading edge. The bottom of the leading edge of the nail serves as the second force-bearing area 22a, contacting an external object to generate the positive normal force from bottom to top as shown in Figure 6. The second pressure sensor 223 is fixed in the space below the nail root. When a scratching or picking action is performed, the positive normal force generates a slight rotation of the nail, forming a nail mechanical measurement. Further, the nail root is radially inserted into the knuckle groove 300. The inner wall of the distal knuckle and the second pressure sensor 223 together form a clamping mechanism for the artificial nail. There is a gap between the artificial nail and the inner wall of the distal knuckle and / or the second pressure sensor, allowing the artificial nail to slide. The clamping of the groove inner wall and the second pressure sensor enhances the overall structural stability. The top surface of the nail root forms an abutment to guide the nail to translate under the negative normal force.

[0042] Figure 8 illustrates the downward tilt of the nail tip, which creates an offset from its extension direction. This downward tilt allows the nail to contact an external object using the lower edge of its leading edge, guiding the point of force application in the second force zone. The nail tip extends slightly outward from the fingertip, a distance of 5%-50% of the nail's radial length. When acting on an external object, the radial direction is limited by the fingertip, restricting the point of contact between the object and the second force zone within acceptable error limits.

[0043] Based on this, Figure 9a shows a schematic diagram of the force on the upper surface of the nail. The artificial nail protrudes from the upper surface of the distal phalanx as the third force-bearing area 23a in contact with external objects. A second pressure sensor 231, which has autonomous elastic recovery after being pressed, is arranged below the third force-bearing area 23a to support the nail and detect the third unidimensional force. When a springing or pressing action is performed, the force forms a negative normal force from top to bottom. As shown in Figure 9b, the third pressure sensor 221 is located directly below the third force-bearing area 22a. The elasticity of the pressure sensor allows the nail to move downward to a certain extent under the negative normal force while detecting the third unidimensional force. The numerical difference between the third unidimensional force and the negative normal force is small. The processing module is coupled to the third pressure sensor 231 and outputs the negative normal force acting on the third force-bearing area based on the third unidimensional force. Furthermore, Figure 9a illustrates the second pressure sensor 223 and the third pressure sensor 231 being arranged on the same side. In this case, the force sensors 223 and 231 are located together on the bottom surface of the artificial fingernail as a support, utilizing the space at the top of the fingertip at the bottom of the fingernail as a housing, which facilitates the compact structure of the pressure detection component on the distal phalanx. More preferably, the upper edge of the slot 300 is reused as the first fulcrum, further achieving a compact structure by using the upper edge of the slot as the first fulcrum, which facilitates the distal phalanx simulating the size of a human finger.

[0044] This invention, based on the consideration that the distal phalanx has only one degree of rotational freedom in one direction, decomposes and senses the force on the nail. It comprehensively evaluates the nail's force status through several dimensions, including positive normal force and torque, negative normal force, and distal radial force, to achieve nail force perception. At the same time, the force perception task in the three directions is distributed to three sensors at different locations, which helps to save sensor space and cost, and completes the biomimetic task of simulating the size of a human finger.

[0045] As an alternative improvement, the pressure detection component is provided with multiple sensing electrodes 400 forming a multi-row, multi-column electrode array. This array is used to sense the approach of an object to the force-bearing area and / or its contact with that area. The electrode array can be arranged on the surface and / or beneath the force-bearing area, forming proximity and / or contact sensing in, but not limited to, a first, second, and / or third force-bearing area. As an example, Figure 10 shows the arrangement of the electrode array sensing the third force-bearing area. In Figure 10, a flexible FPC board 401 is attached to the bottom surface of a fingernail beneath the third force-bearing area. The sensing electrodes 400 are distributed in an array on the FPC, and the fingernail presses against the third pressure sensor via the FPC. It should be understood that, where design allows, using a transparent conductive material for the sensing electrodes 400 on the surface of the third force-bearing area achieves essentially the same purpose. A capacitance-to-digital conversion circuit couples each sensing electrode in the electrode array to obtain self-capacitance and / or mutual capacitance. A processing module, also coupled to the capacitance-to-digital conversion circuit, outputs an electrical signal sensing the approach of an external object and / or outputs the location of the force point and / or the force area acting on the force-bearing zone based on the self-capacitance and / or mutual capacitance. When an external object approaches but does not contact the force-bearing zone, the approach of a conductive or non-conductive external object changes the dielectric constant within the mutual capacitance electric field, causing a change in mutual capacitance. Alternatively, the approach of a conductive object couples with the electrodes, causing a change in self-capacitance. The approach of the object is sensed through changes in self-capacitance and / or mutual capacitance. When the object contacts the force-bearing zone, the significant difference in mutual capacitance and / or self-capacitance between the electrodes in the contact area and the electrodes in the non-contact area of ​​the array is utilized to sense the contact boundary and location of the object, outputting the force point and / or the force area.

[0046] The retraction and extension of animal nails has biomimetic significance. For applications requiring sharp nails, the retraction and extension of artificial nails provide external protection under normal conditions. As an improved solution, the artificial nail includes a body, with the leading edge of the nail movably and retractably positioned at the front end of the body. A pressure detection component is equipped with an actuation device that drives the leading edge of the nail to extend or retract from the body. The actuation method can be electric or manual. As an example, in the manual solution, the leading edge of the nail can be spring-loaded to extend from the inner cavity of the body, with the rear end of the leading edge abutting against the inner cavity via a spring. The leading edge is locked by a press-type latch structure at both the first extended position and the second retracted position. Pressing the latch structure releases the locked state, allowing the leading edge to be pressed back into the body or popped out.

[0047] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A pressure detection component for sensing the force applied to the tip of a robot's fingernail, characterized in that: Includes distal phalanges, artificial nails, and processing modules; The artificial nail is installed on the distal phalanx, and the nail stiffness is set at 2 Mohs or higher. The leading edge of the nail extends outward from the fingertip of the phalanx, and the end of the leading edge of the nail serves as the first force-bearing zone to make physical contact with external objects. The artificial nail is slidably connected to the distal phalanx along the fingertip direction. Under the force of the first force area, the artificial nail slides toward the phalanx. At least one first pressure sensor with autonomous elastic recovery after being pressed is fixed on the sliding path to detect the first unidimensional force. The outer diameter of the pressure sensor is configured to be at most 100% of the maximum size of the nail. The processing module is coupled to the first pressure sensor and is used to output the force on the first force-bearing area based on the first unidimensional force.

2. The pressure detection component according to claim 1, characterized in that: The protrusion on the inner wall of the distal phalanx cooperates with the groove on the side wall of the artificial nail to form a locking limit for the sliding stroke.

3. The pressure detection component according to claim 1, characterized in that: The base and / or top of the nail tip serve as a second force-bearing zone in contact with external objects; The distal phalanx is provided with a first fulcrum acting on the artificial nail. Under the action of the nail normal force in the second force area, the artificial nail is supported by the first fulcrum and generates a first rotational displacement. At least one second pressure sensor with autonomous elastic recovery after being pressed is fixed on the travel path of the first rotational displacement to detect the second unidimensional force. The processing module is coupled to the second pressure sensor and is used to output the normal force and / or torque acting on the second force area based on the second unidimensional force and the corresponding lever arm.

4. The pressure detection component according to claim 3, characterized in that: The distance from the tip of the nail to the outward-pointing edge is 5%-50% of the nail body.

5. The pressure detection component according to claim 3, characterized in that: The first fulcrum is supported on the upper surface between the nail root and the leading edge. The bottom of the leading edge of the nail serves as the second force-bearing area to contact an external object and generate a normal force. The second pressure sensor is fixed in the space below the nail root.

6. The pressure detection component according to claim 5, characterized in that: The inner wall of the distal phalanx and the second pressure sensor together form a clamping mechanism for the artificial nail, and there is a gap between the artificial nail and the inner wall of the distal phalanx and / or the second pressure sensor, allowing the artificial nail to slide.

7. The pressure detection component according to claim 5, characterized in that: The downward tilt of the nail tip creates a deviation from its direction of extension.

8. The pressure detection component according to claim 5, characterized in that: The artificial fingernail is exposed on the upper surface of the distal phalanx as a third force-bearing area in contact with external objects; At least one third pressure sensor with autonomous elastic recovery after being pressed is arranged below the third force zone of the nail to support the nail. The third pressure sensor is used to detect the third unidimensional force. The processing module is coupled to the third pressure sensor and is used to output the negative normal force acting on the third force zone based on the third single-dimensional force.

9. The pressure detection component according to claim 1, characterized in that: The pressure detection component includes a capacitance-to-digital converter circuit and multiple sensing electrodes; Multiple sensing electrodes form an electrode array, used to sense the approach of an object to the force-bearing area and / or its contact with the force-bearing area; The capacitance-to-digital conversion circuit couples each sensing electrode in the electrode matrix to obtain self-capacitance and / or mutual capacitance. The processing module is coupled with a capacitor-to-digital converter circuit, which is used to output an electrical signal that senses the approach of an external object based on its own capacitance and / or mutual capacitance, and / or to output the position of the force point and / or the force area acting on the force zone.

10. The pressure detection component according to claim 1, characterized in that: The artificial nail includes a body, and the leading edge of the nail is movably and retractably disposed at the front end of the body; The pressure detection component is equipped with an actuator that drives the leading edge of the nail to extend or retract from the body.

11. The pressure detection component according to claim 1, characterized in that: The pressure sensor is configured as a single-dimensional force sensor; Alternatively, the pressure sensor includes a flexible body with an upper electrode inside. The upper electrode is a curved elastic electrode. One or more lower electrodes are disposed below the upper electrode. An insulating layer is disposed on the bottom surface of the upper electrode and / or the top surface of the lower electrode. The projection of the upper electrode relative to the lower electrode covers at least a portion of the area of ​​the lower electrode. When the flexible body is deformed by an external force, the upper electrode changes the indirect contact area with the lower electrode. The pressure detection component includes a capacitance-to-digital conversion circuit. The capacitance-to-digital conversion circuit couples each upper electrode to the lower electrode. The processing module is coupled to the capacitance-to-digital conversion circuit.

12. A bionic finger, characterized in that, Includes the pressure detection component as described in any one of claims 1-11.

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