A robotic plantar multi-source sensor arrangement

Abstract

The application relates to the technical field of robot sole sensing, and discloses a robot sole multi-source sensor arrangement structure which comprises a sole main body, a plurality of force sensors, a posture sensing sensor, a distance sensing sensor, a sensing control module and a flexible foot pad. The sole main body comprises a forefoot part, an arch part and a hindfoot part, the plurality of force sensors are arranged in the forefoot part and the hindfoot part respectively, and form a forefoot honeycomb force sensor array and a hindfoot honeycomb force sensor array; the posture sensing sensor is arranged in the central region of the forefoot honeycomb force sensor array; the distance sensing sensor is arranged in the arch part and is staggered with the forefoot honeycomb force sensor array and the hindfoot honeycomb force sensor array in the bottom surface projection; and the forefoot honeycomb force sensor array and the hindfoot honeycomb force sensor array are separated through the isolation area of the arch part. The application can reduce the sensor space interference and the forefoot and hindfoot mechanical crosstalk, and improve the synchronous sensing precision of the sole stress, posture and distance information.

Description

Technical Field

[0001] This application relates to the field of robot foot sensor technology, and in particular to a multi-source sensor arrangement structure for robot foot. Background Technology

[0002] With the increasing application of humanoid robots, bipedal robots, and other legged robots in service, inspection, rescue, and complex environment operations, the robot's ability to walk stably on unstructured terrain is receiving more and more attention. As the end-effector that directly contacts the ground, the robot's feet need to sense information such as sole contact force, pressure center, shear force, foot posture, and ground height in real time. This information is crucial for the control system to perform gait phase determination, center of gravity adjustment, slip recognition, and terrain adaptation control. Therefore, the rationality of the arrangement of the sole sensing structure directly affects the robot's walking stability and environmental adaptability.

[0003] Existing robotic foot sensing structures typically employ a single six-dimensional force sensor, multiple pressure sensors, tactile array pads, or rectangular array pressure detection units to acquire foot force information. While these structures can detect foot pressure or ground reaction forces to some extent, the irregular shapes of robotic feet, such as the forefoot, arch, and hindfoot, make it difficult for traditional rectangular or strip-shaped sensor arrangements to fully adapt to the foot's contours, easily leading to sampling blind spots and directional detection errors. Furthermore, in existing solutions, the inertial measurement unit, distance sensor, and force sensor are often installed independently, lacking spatial coordination with the foot's force-bearing areas. This can easily cause spatial interference between sensors, poor correspondence between attitude signals and force signals, and limited terrain detection paths.

[0004] Furthermore, the forefoot and heel bear different force functions during the robot's ground contact, support, and push-off processes. If there is a lack of a reasonable mechanical isolation structure between them, the load transfer and structural deformation of the forefoot and heel can easily affect each other, reducing the accuracy of pressure center calculation and gait state judgment. Although flexible foot pads can cushion the impact on the soles of the feet, their deformation under pressure may also introduce errors in force measurement.

[0005] Therefore, there is an urgent need for a robot foot sensor arrangement structure that can reasonably arrange force sensors, inertial measurement units and distance sensors in a limited foot space, while taking into account the mechanical isolation of the forefoot and rearfoot and the force compensation of the flexible foot pad. Summary of the Invention

[0006] The purpose of this invention is to provide a robot foot sensor arrangement structure to solve the problems in existing robot foot sensing structures, such as the difficulty in adapting sensor arrangement to irregularly shaped force areas on the foot, lack of spatial coordination among multiple types of sensors, and easy crosstalk between the forefoot and heel forces, resulting in insufficient accuracy in the synchronous sensing of foot force, posture, and distance information.

[0007] The robot foot multi-source sensor arrangement structure provided in this application adopts the following technical solution: A multi-source sensor arrangement structure for the sole of a robot includes a sole body, multiple force sensors, at least one posture sensing sensor, and at least one distance sensing sensor. The main body of the foot includes the forefoot, the arch, and the hindfoot; A portion of the plurality of force sensors is disposed on the forefoot and forms a forefoot honeycomb force sensor array, and another portion of the plurality of force sensors is disposed on the heel and forms a heel honeycomb force sensor array. At least one of the posture sensing sensors is disposed on the forefoot and located in the central region of the forefoot cellular force sensor array; At least one of the distance sensing sensors is disposed on the arch of the foot, and the distance sensing sensor is offset from the forefoot honeycomb force sensor array and the rearfoot honeycomb force sensor array in the bottom projection of the main body of the foot. The forefoot cellular force sensor array and the heel cellular force sensor array are separated by an isolation zone located in the arch of the foot where no force sensors are installed.

[0008] Furthermore, both the forefoot and the heel are provided with multiple hexagonal mounting units, and multiple force sensors are respectively disposed in the corresponding hexagonal mounting units; in the forefoot honeycomb force sensor array and the heel honeycomb force sensor array, the center distance between adjacent force sensors is equal, and the center line connecting any three adjacent force sensors forms an equilateral triangle.

[0009] Furthermore, the force sensor is a three-dimensional force sensor, which is used to detect the vertical force perpendicular to the bottom surface of the foot sole and the horizontal shear force along the bottom surface of the foot sole.

[0010] Furthermore, the attitude sensing sensor is an inertial measurement unit, and the center of mass projection of the inertial measurement unit is located in the central region of the forefoot cellular force sensor array.

[0011] Furthermore, the distance sensing sensor is an area array TOF distance sensor, the arch of the foot is provided with an installation window facing the bottom of the foot body, the area array TOF distance sensor is disposed in the installation window, and the angle between the detection optical axis of the area array TOF distance sensor and the bottom surface of the foot body is 20° to 45°.

[0012] Furthermore, the arch portion is an upwardly arched elastic connection portion, and the isolation zone is located between the forefoot honeycomb force sensor array and the heel honeycomb force sensor array.

[0013] Furthermore, it also includes a flexible foot pad, which is disposed below the main body of the foot and covers the force-bearing areas corresponding to the forefoot honeycomb force sensor array and the heel honeycomb force sensor array.

[0014] Furthermore, the flexible foot pad includes an airbag foot pad and a fixing and compacting plate. The bottom surface of the foot body is provided with a sealing groove extending along the periphery of the foot body. The upper surface of the airbag foot pad is provided with a sealing protrusion that fits into the sealing groove. The fixing and compacting plate presses the airbag foot pad tightly against the foot body by a plurality of fasteners spaced apart along the periphery of the foot body.

[0015] Furthermore, the airbag foot pad is provided with multiple independent air chambers separated by ribs, and at least some of the independent air chambers are respectively arranged corresponding to the force sensor; the force sensor includes a pressure-sensing end extending toward the airbag foot pad, the pressure-sensing end passes through the foot body and extends into the corresponding independent air chamber, and an elastic seal is provided between the pressure-sensing end and the wall of the airbag foot pad.

[0016] Furthermore, it also includes a sensing and control module, in which the force sensor, the attitude sensing sensor, and the distance sensing sensor are all electrically connected; the sensing and control module includes a multi-layer circuit board, which has a force sensor signal conditioning circuit layer, a sensor driving circuit layer, a data aggregation interface layer, and an electromagnetic shielding layer disposed between adjacent circuit layers; the sensing and control module also includes a temperature sensor and a zero-point calibration circuit.

[0017] In summary, this application includes at least one of the following beneficial technical effects: 1. This invention sets up honeycomb force sensor arrays in the forefoot and heel respectively, so that multiple force sensors can better adapt to the irregular force-bearing areas of the robot's foot. Compared with the traditional rectangular array or strip arrangement, it can reduce sampling blind spots and directional detection errors, and improve the accuracy of foot pressure distribution, pressure center and shear force detection. 2. In this invention, the posture sensing sensor is placed in the central area of ​​the forefoot honeycomb force sensor array, and the distance sensing sensor is placed in the arch of the foot. This allows the posture sensing, distance sensing, and foot force sensing to form a staggered and coordinated layout within the main body of the foot, which reduces spatial interference between multiple types of sensors and facilitates the simultaneous acquisition of foot force information, posture information, and terrain distance information. 3. This invention separates the forefoot honeycomb force sensor array and the heel honeycomb force sensor array by using an isolation zone located in the arch of the foot that does not have force sensors. This allows the force states of the forefoot and heel to be collected and calculated separately, reducing mechanical crosstalk between the forefoot and heel caused by structural deformation and load transmission. This improves the accuracy of gait phase judgment, support state identification, and pressure center calculation. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the overall structure of the robot foot sensor arrangement in an embodiment of the present invention.

[0020] Figure 2 This is an exploded structural diagram of the robot foot sensor arrangement structure in an embodiment of the present invention.

[0021] Figure 3 This is a schematic diagram of the bottom structure of the foot body in an embodiment of the present invention.

[0022] Figure 4 This is a schematic diagram of the flexible foot pad structure in an embodiment of the present invention.

[0023] Figure 5 This is a cross-sectional view showing the assembly relationship of the foot body, airbag foot pad, and fixing and compacting plate in an embodiment of the present invention.

[0024] Reference numerals: 1. Main body of the foot; 101. Forefoot; 1011. Posture sensing sensor; 1012. Forefoot force sensor; 1013. Sealing groove; 1014. Fixing bolt hole; 102. Arch of the foot; 1021. Distance sensing sensor; 103. Heel; 1031. Heel force sensor; 2. Sensing and control module; 3. Flexible foot pad; 301. Airbag foot pad; 3011. Sealing protrusion; 302. Fixing and compacting sheet. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0026] This application discloses a multi-source sensor arrangement structure for the sole of a robot's foot. (Refer to...) Figures 1 to 5 The robot's foot multi-source sensor arrangement structure includes a foot body 1, multiple force sensors, at least one posture sensing sensor 1011, at least one distance sensing sensor 1021, a sensing and control module 2, and a flexible foot pad 3. The foot body 1 bears the force sensors, posture sensing sensor 1011, distance sensing sensor 1021, sensing and control module 2, and flexible foot pad 3. Multiple force sensors collect contact force information at different locations on the robot's foot. The posture sensing sensor 1011 collects the robot's foot posture information. The distance sensing sensor 1021 collects distance or terrain information of the area beneath the foot. The sensing and control module 2 is electrically connected to each sensor and aggregates the sensing signals. The flexible foot pad 3 is placed under the foot body 1 to cushion ground impacts and assist in force transmission. Thus, the robot's foot can simultaneously acquire foot force information, foot posture information, and distance information beneath the foot within a limited installation space.

[0027] like Figure 1 As shown, the main body 1 of the foot is shaped like a human foot, comprising a forefoot 101, an arch 102, and a heel 103 connected in sequence. The forefoot 101 is located at the front end of the main body 1, the heel 103 is located at the rear end, and the arch 102 is located between the forefoot 101 and the heel 103. Both the forefoot 101 and the heel 103 are support areas with a width greater than the arch 102, forming the main ground contact area of ​​the robot's foot. The arch 102 is a waist-like connecting area located between the forefoot 101 and the heel 103, connecting the forefoot 101 and the heel 103, and providing mounting space for the distance sensing sensor 1021. Through the above shape design, the main body 1 of the foot can adapt to the force characteristics of the forefoot 101 and the heel 103 bearing the main load during robot walking, while the arch 102 bears the transition connection and sensor avoidance.

[0028] Specifically, both the forefoot portion 101 and the rearfoot portion 103 have mounting surfaces for arranging force sensors. A portion of the multiple force sensors is disposed in the forefoot portion 101, forming a forefoot honeycomb force sensor array; another portion of the multiple force sensors is disposed in the rearfoot portion 103, forming a rearfoot honeycomb force sensor array. The forefoot honeycomb force sensor array covers the main force-bearing area of ​​the forefoot portion 101, and the rearfoot honeycomb force sensor array covers the main force-bearing area of ​​the rearfoot portion 103. Thus, the forefoot portion 101 and the rearfoot portion 103 can each form relatively independent force sampling areas, facilitating the zonal acquisition and analysis of the force states in the forefoot and rearfoot regions.

[0029] Furthermore, such as Figure 1 and Figure 3As shown, both the forefoot 101 and the rearfoot 103 are provided with multiple hexagonal mounting units, which are adjacent to each other and form a honeycomb distribution. Each hexagonal mounting unit is a mounting area with a hexagonal outline, and the force sensor is located in the center of the corresponding hexagonal mounting unit. In the forefoot and rearfoot honeycomb force sensor arrays, the center distance between adjacent force sensors is equal, and the line connecting the centers of any three adjacent force sensors forms an equilateral triangle, thus forming a relatively uniform two-dimensional mechanical sampling structure. Compared with rectangular or strip arrays, this honeycomb arrangement can better adapt to the irregular contours of the forefoot 101 and rearfoot 103, reduce the sampling blind zone in the edge area, and reduce the detection error caused by different sampling directions.

[0030] In this embodiment, both the forefoot force sensor 1012 and the rearfoot force sensor 1031 can be three-dimensional force sensors. The three-dimensional force sensors can detect vertical forces perpendicular to the bottom surface of the foot body 1 and horizontal shear forces along the bottom surface of the foot body 1. When the robot's foot touches the ground, the forefoot force sensor 1012 and the rearfoot force sensor 1031 respectively collect the vertical load and horizontal shear load at their corresponding positions, enabling the sensing and control module 2 to further obtain the foot pressure distribution, the pressure center position, and the foot slippage trend. Therefore, this embodiment can not only detect the load on the foot but also provide a data basis for judging the robot's gait stability and slippage risk.

[0031] Additionally, a central mounting area is formed in the middle of the forefoot portion 101, and the attitude sensing sensor 1011 is disposed within this central mounting area. The central mounting area is located in the central region of the forefoot honeycomb force sensor array and is surrounded or adjacent to multiple forefoot force sensors 1012. Preferably, the forefoot portion 101 has a central mounting base within the central region of the forefoot honeycomb force sensor array. The central mounting base can be a boss-shaped, groove-shaped, or plate-shaped mounting structure. The attitude sensing sensor 1011 is fixed on the central mounting base and electrically connected to the sensing and control module 2. In this embodiment, the attitude sensing sensor 1011 can be an inertial measurement unit (IMU) used to collect acceleration and angular velocity signals from the robot's foot. Because the attitude sensing sensor 1011 is located in the central region of the forefoot honeycomb force sensor array, the attitude information it collects has a good spatial correspondence with the main force-bearing areas of the forefoot portion 101, thereby helping to reduce attitude calculation errors caused by the biased arrangement of the attitude sensing sensor 1011.

[0032] To further improve the correspondence between posture detection and force detection, the centroid projection of the posture sensing sensor 1011 can be located within the central region of the forefoot honeycomb force sensor array. That is, the projection position of the posture sensing sensor 1011 on the bottom surface of the foot body 1 corresponds to the center position of the forefoot honeycomb force sensor array. Therefore, during robot walking, the inertial data acquired by the posture sensing sensor 1011 can be better synchronized with the force data in the forefoot region for analysis, facilitating the robot control system's judgment of foot posture changes, ground contact posture, and slippage trends. In alternative embodiments, the posture sensing sensor 1011 can also be an accelerometer, a gyroscope, a tilt sensor, or a combination of the above sensors.

[0033] like Figure 2 As shown, the sensing module 2 is positioned above the foot sole body 1. The sensing module 2 can be a board-shaped circuit module, with a long strip or rectangular board structure, and is fixed to the foot sole body 1 via connecting posts, support posts, screws, clips, or plug-in structures. The forefoot force sensor 1012, rearfoot force sensor 1031, posture sensing sensor 1011, and distance sensing sensor 1021 are all electrically connected to the sensing module 2. Specific connection methods include soldering, plug-in, flexible circuit board connection, or wire harness connection. By positioning the sensing module 2 above the foot sole body 1, sensor signals can be aggregated within or near the foot sole body 1, reducing external wiring length and improving signal acquisition stability.

[0034] Preferably, the sensing and control module 2 includes a multi-layer circuit board. The multi-layer circuit board has a force sensor signal conditioning circuit layer, a sensor driving circuit layer, and a data aggregation interface layer, with an electromagnetic shielding layer between adjacent circuit layers. Specifically, the force sensor signal conditioning circuit layer amplifies, filters, and converts the force signals output by the forefoot force sensor 1012 and the rearfoot force sensor 1031; the sensor driving circuit layer drives the attitude sensing sensor 1011 and the distance sensing sensor 1021; and the data aggregation interface layer outputs various types of sensor data to the robot's central controller. Through layered arrangement and electromagnetic shielding, hardware crosstalk between different sensor signals can be reduced, improving the stability of multi-source sensor data acquisition.

[0035] Furthermore, the sensing and control module 2 may also be equipped with a temperature sensor and a zero-point calibration circuit. The temperature sensor is used to detect the ambient temperature inside the foot body 1 or near the flexible foot pad 3. The zero-point calibration circuit is used to collect the current output values ​​of each force sensor when the robot's foot is off the ground or in a state without external load, and update the current output values ​​as the zero-point reference value for the stress sensor. Through temperature detection and zero-point calibration, measurement drift caused by assembly pre-tightening, initial pressure of the flexible foot pad 3, and changes in ambient temperature can be compensated, thereby improving the measurement stability of this embodiment during long-term use.

[0036] like Figure 2 and Figure 3 As shown, a distance sensing sensor 1021 is disposed on the arch portion 102. The arch portion 102 has a mounting area located between the forefoot honeycomb force sensor array and the heel honeycomb force sensor array, which is used to mount the distance sensing sensor 1021. The distance sensing sensor 1021 is offset from the projection of the forefoot and heel honeycomb force sensor arrays onto the bottom surface of the foot body 1, that is, the projection of the distance sensing sensor 1021 onto the bottom surface of the foot body 1 does not overlap with the projections of the forefoot force sensor 1012 and the heel force sensor 1031. Through the above-mentioned offset arrangement, the distance sensing sensor 1021 can avoid the main contact force areas of the forefoot portion 101 and the heel portion 103, reducing the influence of foot impact, flexible deformation, and force sensor mounting space on distance detection.

[0037] Specifically, the distance sensing sensor 1021 can be an area array TOF distance sensor. The arch portion 102 has a mounting window facing downwards towards the foot body 1. This mounting window can be a rectangular, square, circular, or recessed hole penetrating the arch portion 102. The distance sensing sensor 1021 is disposed within this mounting window, with its detection surface facing downwards towards the foot body 1. Preferably, the detection optical axis of the area array TOF distance sensor is tilted relative to the bottom surface of the foot body 1, with the angle between the detection optical axis and the bottom surface of the foot body 1 being between 20 and 45 degrees. This tilt angle allows the distance sensing sensor 1021 to detect changes in ground height in the area in front of and below the foot when the robot's foot is in a swinging phase, thus providing distance information for adjusting the robot's foot lifting height, determining slope, and identifying steps or potholes. In alternative embodiments, the distance sensing sensor 1021 can also be a laser rangefinder, an infrared distance sensor, an ultrasonic distance sensor, a structured light depth sensor, or a depth camera.

[0038] Furthermore, the forefoot and heel honeycomb force sensor arrays are separated by an isolation zone located in the arch 102 where no force sensors are installed. This isolation zone is located between the forefoot 101 and the heel 103 and extends laterally along the main body 1 of the foot. It should be noted that the absence of force sensors in the isolation zone does not preclude the installation of a distance sensing sensor 1021 in the arch 102. Through this isolation zone, the forefoot and heel honeycomb force sensor arrays are structurally arranged in a partitioned manner, allowing the force states of the forefoot 101 and heel 103 to be collected and calculated separately, reducing mechanical crosstalk between the forefoot 101 and heel 103 caused by structural deformation and load transfer.

[0039] Furthermore, the arch portion 102 can be an upwardly arched elastic connection portion. Specifically, the bottom surface of the arch portion 102 converges upward relative to the bottom surfaces of the forefoot portion 101 and the rearfoot portion 103, forming a transition connection structure with an arched profile. The arch portion 102 can be made of elastic metal material, composite material, or polymer material with elastic deformation capability. When the forefoot portion 101 and the rearfoot portion 103 are subjected to force during robot walking, the upwardly arched arch portion 102 can form an elastic transition between the forefoot portion 101 and the rearfoot portion 103, which is beneficial for cushioning impact and can also reduce force interference between the forefoot honeycomb force sensor array and the rearfoot honeycomb force sensor array.

[0040] like Figure 4 As shown, the flexible foot pad 3 is disposed below the foot body 1 and matches the bottom shape of the foot body 1. The flexible foot pad 3 is a sheet-like or pad-like structure adapted to the outer contour of the foot body 1, and it can cover the force-bearing areas corresponding to the forefoot and rearfoot honeycomb force sensor arrays. The flexible foot pad 3 includes an airbag foot pad 301 and a fixed compaction plate 302. The airbag foot pad 301 is located between the foot body 1 and the fixed compaction plate 302, and is used to generate elastic deformation and buffer the impact of the ground when the robot's foot touches the ground; the fixed compaction plate 302 is located on the side of the airbag foot pad 301 away from the foot body 1, and is used to press the airbag foot pad 301 tightly under the foot body 1. With the setting of the flexible foot pad 3, the ground load can be transmitted to the force sensor more continuously, thereby improving the stability of the foot force detection.

[0041] Specifically, the airbag foot pad 301 is an elastic pad with an internal air cavity, and its outer contour is adapted to the outer contour of the bottom surface of the foot body 1. The airbag foot pad 301 can be made of silicone, rubber, thermoplastic elastomer, or other materials with elastic recovery capabilities. When the airbag foot pad 301 is compressed, its internal air cavity undergoes compression deformation, which can absorb the local impact when the robot's foot touches the ground and assist the force sensor in sensing local force changes. The fixing and compacting plate 302 can be a flexible sheet, a semi-rigid sheet, or a thin plate, and its contour is adapted to the airbag foot pad 301, and it is provided with mounting holes or connecting posts for connection to the foot body 1.

[0042] Furthermore, the airbag footpad 301 contains multiple independent air chambers separated by ribs. The ribs are strip-shaped or wall-shaped partitions within the airbag footpad 301, dividing the internal space into multiple independent or relatively independent air chambers. These independent air chambers can be distributed along corresponding areas of the forefoot 101 and heel 103, with at least some of the independent air chambers corresponding to either the forefoot force sensor 1012 or the heel force sensor 1031. Through this correspondence between the independent air chambers and the force sensors, the deformation and pressure changes of the airbag footpad 301 under localized pressure can be correlated with the force sensors at the corresponding locations, thus providing a structural basis for deformation compensation of the flexible footpad 3.

[0043] like Figure 5 As shown, the bottom surface of the foot body 1 is provided with a sealing groove 1013, and the upper surface of the airbag foot pad 301 is provided with a sealing protrusion 3011 that matches the sealing groove 1013. The sealing groove 1013 is a recessed groove structure extending along the periphery of the foot body 1, and the sealing protrusion 3011 is a raised strip structure extending along the periphery of the upper surface of the airbag foot pad 301. During assembly, the sealing protrusion 3011 is embedded in the sealing groove 1013, so that the airbag foot pad 301 and the foot body 1 form a circumferential positioning and sealing fit. As a result, the airbag foot pad 301 can maintain a stable position relative to the foot body 1 and reduce the risk of the airbag foot pad 301 shifting, warping or leaking during walking.

[0044] Furthermore, the foot sole body 1 is provided with multiple fixing bolt holes 1014, which are spaced apart circumferentially along the foot sole body 1 and can be arranged in the adjacent areas of the forefoot 101, the arch 102, and the periphery of the heel 103. The fixing compression plate 302 is connected to the foot sole body 1 by fasteners passing through the fixing bolt holes 1014, thereby pressing the airbag foot pad 301 between the foot sole body 1 and the fixing compression plate 302. The fasteners can be screws, bolts, rivets, or other detachable connectors. The multiple fasteners are distributed circumferentially to form a more uniform compression force on the airbag foot pad 301, preventing local warping or sealing failure of the airbag foot pad 301.

[0045] Additionally, the force sensor includes a pressure-sensing end extending toward the airbag foot pad 301. The pressure-sensing end extends downward from the force sensor body, passes through the foot body 1, and extends into the corresponding independent air chamber. The pressure-sensing end can be cylindrical, spherical, annular, cross-shaped, or other structures capable of interacting with the pressure within the independent air chamber. Preferably, an elastic seal is provided between the pressure-sensing end and the wall of the airbag foot pad 301. The elastic seal can be a silicone sealing ring, a rubber sealing ring, an elastic sleeve, or a sealing layer, used to form a seal at the location where the pressure-sensing end passes through the wall of the airbag foot pad 301. Thus, while ensuring that the pressure-sensing end can sense pressure changes within the independent air chamber, the airtightness of the independent air chamber can be maintained, reducing the impact of gas leakage on the detection results.

[0046] This embodiment also provides a synchronous sensing process based on the above-described robot foot sensor arrangement structure. This synchronous sensing process is implemented based on the foot body 1, the forefoot honeycomb force sensor array, the rearfoot honeycomb force sensor array, the attitude sensing sensor 1011, the distance sensing sensor 1021, the sensing and control module 2, and the flexible foot pad 3, which is used to illustrate the cooperative working relationship between the various structures in this embodiment.

[0047] First, when the robot's feet are off the ground or without external load, the sensing and control module 2 collects the current output values ​​of each forefoot force sensor 1012 and each rearfoot force sensor 1031 through the zero-point calibration circuit, and uses these current output values ​​as the zero-point reference values ​​for the stress sensors. Simultaneously, the sensing and control module 2 can collect temperature information from the foot body 1 or near the flexible foot pad 3 through a temperature sensor, and perform temperature compensation on the zero-point reference values ​​or force sensor output values ​​based on this temperature information. This reduces the impact of assembly pre-tightening, the initial pressure of the flexible foot pad 3, and changes in ambient temperature on the foot force detection results.

[0048] When the robot's foot touches the ground, the flexible footpad 3 first contacts the ground and undergoes elastic deformation. The ground load is transmitted to the corresponding forefoot force sensor 1012 and rearfoot force sensor 1031 via the airbag footpad 301. The forefoot honeycomb force sensor array collects the vertical force and horizontal shear force at multiple sampling points on the forefoot 101, while the rearfoot honeycomb force sensor array collects the vertical force and horizontal shear force at multiple sampling points on the rearfoot 103. Because the forefoot force sensor 1012 and rearfoot force sensor 1031 are arranged in a honeycomb pattern, the sampling points are relatively evenly distributed within the pressure-bearing area of ​​the sole, thus improving the completeness and consistency of sole pressure distribution detection.

[0049] Subsequently, the sensing and control module 2 calculates the resultant force, pressure center, and shear force direction of the forefoot region based on the output of the forefoot honeycomb force sensor array, and calculates the resultant force, pressure center, and shear force direction of the rearfoot region based on the output of the rearfoot honeycomb force sensor array. Since the forefoot and rearfoot honeycomb force sensor arrays are separated by the arch support 102, the force states of the forefoot 101 and rearfoot 103 can be calculated separately, thereby reducing the impact of crosstalk caused by structural deformation and load transfer between the forefoot and rearfoot on the pressure center determination results.

[0050] While collecting force data on the sole of the foot, the posture sensing sensor 1011 simultaneously collects acceleration, angular velocity, or tilt signals of the robot's foot. The sensing and control module 2 obtains foot posture change information based on these posture signals. Since the posture sensing sensor 1011 is located in the central area of ​​the forefoot honeycomb force sensor array, the posture signals have a good spatial correspondence with the main force-bearing areas of the forefoot, thus facilitating the synchronous analysis of foot posture changes and force changes on the forefoot 101.

[0051] Simultaneously, the distance sensing sensor 1021 synchronously collects distance information or terrain information of the area beneath the foot. If the distance sensing sensor 1021 is an area array TOF distance sensor, it can collect distance array information or point cloud information of the area beneath the foot. The sensing and control module 2 obtains the height of the foot relative to the ground, the ground slope, and the height change information of the area below the front based on this distance array information or point cloud information. Since the distance sensing sensor 1021 is located in the arch of the foot 102 and is staggered from the forefoot honeycomb force sensor array and the heel honeycomb force sensor array, the influence of the ground contact deformation of the forefoot 101 and the heel 103 on distance detection can be reduced.

[0052] Furthermore, in an embodiment with multiple independent air chambers, when the airbag foot pad 301 is compressed, the pressure within the corresponding independent air chamber changes, and this pressure change acts on the pressure-sensing end extending into the independent air chamber. The sensing and control module 2 can correct the nonlinear error caused by local deformation of the flexible foot pad 3 based on the output change of the stress sensor and the pressure change of the independent air chamber. Thus, the flexible foot pad 3 can both provide cushioning and help improve the accuracy of local force detection.

[0053] Finally, the sensing and control module 2 synchronizes the force information of the forefoot area, the force information of the heel area, the foot posture information, and the distance information of the foot in time, and determines the state of the robot's foot based on the synchronized multi-source sensor information. When the resultant force of the forefoot area or the resultant force of the heel area is detected to be greater than the preset ground contact threshold, it can be determined that the robot's foot has entered the ground contact state; when the resultant force of both the forefoot area and the resultant force of the heel area are detected to be less than the preset ground lift threshold, and the distance sensing sensor 1021 detects that the height of the foot is greater than the preset height, it can be determined that the robot's foot is in a swinging state. When a rapid shift of the pressure center is detected and the horizontal shear force exceeds the preset shear force threshold, it can be determined that there is a risk of slippage; when a step, pit, or sudden change in slope is detected in the lower front of the foot, a foot lift height adjustment signal or gait adjustment signal can be output to the robot's central controller.

[0054] Therefore, this embodiment achieves multi-point force information acquisition of the sole through a forefoot cellular force sensor array and a heel cellular force sensor array, acquires foot posture information through an attitude sensing sensor 1011 located in the central area of ​​the forefoot cellular force sensor array, acquires sole distance or terrain information through a distance sensing sensor 1021 located in the arch 102 and offset from the force sensor array, and reduces mechanical crosstalk between the forefoot 101 and the heel 103 through the isolation zone of the arch 102, thereby achieving low-coupling synchronous perception of force information, posture information and distance information within a limited sole space.

[0055] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention 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; and these 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 the present invention.

Claims

1. A robotic foot plant multi-source sensor arrangement, characterized by, It includes a foot-shaped main body, multiple force sensors, at least one posture sensing sensor, and at least one distance sensing sensor; The main body of the foot includes the forefoot, the arch, and the hindfoot; A portion of the plurality of force sensors is disposed on the forefoot and forms a forefoot honeycomb force sensor array, and another portion of the plurality of force sensors is disposed on the heel and forms a heel honeycomb force sensor array. At least one of the posture sensing sensors is disposed on the forefoot and located in the central region of the forefoot cellular force sensor array; At least one of the distance sensing sensors is disposed on the arch of the foot, and the distance sensing sensor is offset from the forefoot honeycomb force sensor array and the rearfoot honeycomb force sensor array in the bottom projection of the main body of the foot. The forefoot cellular force sensor array and the heel cellular force sensor array are separated by an isolation zone located in the arch of the foot where no force sensors are installed.

2. The robot foot multi-source sensor arrangement structure according to claim 1, characterized in that, Both the forefoot and the heel are provided with multiple hexagonal mounting units, and multiple force sensors are respectively disposed in the corresponding hexagonal mounting units; in the forefoot honeycomb force sensor array and the heel honeycomb force sensor array, the center distance between adjacent force sensors is equal, and the center line connecting any three adjacent force sensors forms an equilateral triangle.

3. The robot foot multi-source sensor arrangement structure according to claim 1, characterized in that, The force sensor is a three-dimensional force sensor, which is used to detect the vertical force perpendicular to the bottom surface of the foot sole and the horizontal shear force along the bottom surface of the foot sole.

4. The robot foot multi-source sensor arrangement structure according to claim 1, characterized in that, The attitude sensing sensor is an inertial measurement unit, and the center of mass projection of the inertial measurement unit is located in the central region of the forefoot cellular force sensor array.

5. The robot foot multi-source sensor arrangement structure according to claim 1, characterized in that, The distance sensing sensor is an area array TOF distance sensor. The arch of the foot is provided with an installation window facing the bottom of the foot body. The area array TOF distance sensor is disposed in the installation window, and the angle between the detection optical axis of the area array TOF distance sensor and the bottom surface of the foot body is 20° to 45°.

6. The robot foot multi-source sensor arrangement structure according to claim 1, characterized in that, The arch portion is an upwardly arched elastic connection portion, and the isolation zone is located between the forefoot honeycomb force sensor array and the heel honeycomb force sensor array.

7. The robot foot multi-source sensor arrangement structure according to claim 1, characterized in that, It also includes a flexible foot pad, which is disposed below the main body of the foot and covers the force-bearing areas corresponding to the forefoot honeycomb force sensor array and the heel honeycomb force sensor array.

8. The robot foot multi-source sensor arrangement structure according to claim 7, characterized in that, The flexible foot pad includes an airbag foot pad and a fixing and pressing plate. The bottom surface of the foot body is provided with a sealing groove extending along the periphery of the foot body. The upper surface of the airbag foot pad is provided with a sealing protrusion that fits into the sealing groove. The fixing and pressing plate presses the airbag foot pad against the foot body by a plurality of fasteners spaced apart along the periphery of the foot body.

9. The robot foot multi-source sensor arrangement structure according to claim 8, characterized in that, The airbag foot pad has multiple independent air chambers separated by ribs, and at least some of the independent air chambers are respectively arranged corresponding to the force sensor; the force sensor includes a pressure-sensing end extending toward the airbag foot pad, the pressure-sensing end passes through the foot body and extends into the corresponding independent air chamber, and an elastic seal is provided between the pressure-sensing end and the wall of the airbag foot pad.

10. The robot foot multi-source sensor arrangement structure according to claim 1, characterized in that, It also includes a sensing and control module, in which the force sensor, the attitude sensing sensor, and the distance sensing sensor are all electrically connected; the sensing and control module includes a multi-layer circuit board, which has a force sensor signal conditioning circuit layer, a sensor driving circuit layer, a data aggregation interface layer, and an electromagnetic shielding layer disposed between adjacent circuit layers; the sensing and control module also includes a temperature sensor and a zero-point calibration circuit.

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