Baby carriage power-assisted walking mechanism based on mechanical linkage pressure induction

Abstract

The invention discloses a baby carriage power-assisted walking mechanism based on mechanical linkage pressure induction, which comprises a frame, a front universal wheel, a rear wheel and a motor for driving the rear wheel, a U-shaped handle is arranged on the frame, a rigid pressure sensor and a controller are arranged in the U-shaped handle, a pressing surface for pressing the rigid pressure sensor is formed on the surface of the U-shaped handle, and the rigid pressure sensor is arranged on the pressing surface of the U-shaped handle. The rigid pressure sensors are symmetrically distributed on the two sides of the interior of the U-shaped handle, the sensing surfaces of the rigid pressure sensors abut against the pressing surfaces through mechanical linkage structures, and the controller is electrically connected with the rigid pressure sensors and the motor and used for dynamically adjusting the torque and the rotating speed of the motor according to the output voltage of the pressure sensors. According to the invention, the response delay is less than 0.1 second, and the thrust demand is reduced by 60%, so that the real-time linear matching of the user pressing force and the motor rotating speed is realized.

Description

TECHNICAL FIELD

[0001] The present application relates to a power-assisted system for a smart stroller, in particular to a stroller walking assisting mechanism based on mechanical linkage pressure sensing. BACKGROUND

[0002] A stroller is a tool car designed to facilitate outdoor activities for babies, and has become an essential carrying tool for children during their growth. It is not only convenient to move, but also helps parents reduce physical labor, and can carry toys and other supplies to facilitate baby play.

[0003] However, the existing stroller needs to exert an additional 30%-50% pushing force when pushing on a slope, and the motor assistance scheme mostly uses button / knob control, which has the problems of operation interruption (need to release the hand to adjust) and response delay (more than 0.5s), and cannot realize real-time cooperation of pushing force and assistance. SUMMARY

[0004] In order to overcome the above-mentioned deficiencies in the prior art, the purpose of the present application is to provide a stroller walking assisting mechanism based on mechanical linkage pressure sensing, which has a response delay of less than 0.1 second and a reduction of 60% in pushing force requirement, to realize real-time linear matching of user pressing force and motor speed.

[0005] The present application is realized by the following technical scheme: a stroller walking assisting mechanism based on mechanical linkage pressure sensing, comprising a frame (1), a front universal wheel (2), a rear wheel (3), and a motor (4) driving the rear wheel, the frame (1) is provided with a U-shaped handle (5), the U-shaped handle (5) is internally provided with a rigid pressure sensor and a controller (6), a pressing surface (7) for pressing the rigid pressure sensor is formed on the surface of the U-shaped handle (5), the rigid pressure sensors are symmetrically distributed on both sides of the inside of the U-shaped handle (5), and the sensing surfaces thereof are in abutment with the pressing surface (7) through a mechanical linkage structure, the controller (6) is electrically connected with the rigid pressure sensor and the motor (4) respectively, and is used for dynamically adjusting the torque and speed of the motor (4) according to the output voltage of the pressure sensor.

[0006] Preferably, the U-shaped handle (5) of the present application is detachably assembled by an upper buckle cover (50) and a lower buckle cover (51), the upper buckle cover (50) and the lower buckle cover (51) are provided with a support piece (52) and an elastic piece (53), the rigid pressure sensor is fixed to the lower buckle cover (51), the pressure receiving end thereof is in contact with the support piece (52), and the elastic piece (53) is supported between the inner wall of the upper buckle cover (50) and the support piece (52), and is used for transmitting the pressing pressure and resetting.

[0007] Preferably, the lower buckle cover (51) of the present invention is provided with a positioning column (55), the positioning column (55) passes through the through hole (56) of the limiting plate (54), the limiting plate (54) fixes the support member (52) and moves axially between the limiting groove (58) of the positioning column (55) and the limiting plug (57), and the inner wall of the upper buckle cover (50) is provided with a top column (59) for pressing the limiting plug (57) to maintain structural stability.

[0008] Preferably, the lower buckle cover (51) of the present invention is provided with a guide column (8), and the guide column (8) is provided with a reset spring (9), and the reset spring (9) is a variable pitch spring, the wire diameter of the variable pitch spring is 0.8 mm, and the initial pressure is 5N±1N. The two ends of the reset spring (9) respectively abut against the inner wall of the upper buckle cover (50) and the inner wall of the lower buckle cover (51), and are used for automatic reset after pressing.

[0009] Preferably, the upper buckle cover (50) and the lower buckle cover (51) of the present invention are connected via a magnetic snap-fit ​​structure (the magnetic attraction force is greater than 8N); an opening (510) for the upper buckle cover (50) to be embedded is provided in the center of the lower buckle cover (51).

[0010] Preferably, the controller (6) of the present invention has a built-in signal processing module for executing the following Figure 3 The control logic shown is: converting the analog voltage signal of the pressure sensor into a digital signal and controlling the acceleration curve of the motor (4) through the PID algorithm.

[0011] Preferably, the rigid pressure sensor of the present invention is a thin film piezoresistive sensor, the resistance change rate of which is k = 0.4-0.6Ω / N, and the output voltage range thereof is linearly mapped to the rotation speed of the motor (4).

[0012] Preferably, the surface of the rigid pressure sensor of the present invention is covered with a silicone buffer layer.

[0013] Preferably, the proportional coefficient Kp of the PID algorithm of the present invention is in the range of 0.5-1.0, the integral coefficient Ki is in the range of 0.05-0.15, and the differential coefficient Kd is in the range of 0.01-0.1.

[0014] Compared with the prior art, the present invention has the following advantages and beneficial effects: 1. Improved real-time performance: the time from pressure detection to motor response is shortened to 0.08-0.1 seconds; 2. Energy saving: When pushing on a 10° slope, the user's thrust is reduced from 18N to 3N (measured value); 3. Human-machine collaboration: Through nonlinear elastic design, it can achieve slow start with light press (<5N) and fast response with hard press (>10N). BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Other features, objects and advantages of the present invention will become more apparent upon reading the detailed description of non-limiting embodiments with reference to the following drawings: Figure 1 It is a structural schematic diagram of the present invention; Figure 2 This is a partial exploded view of the U-shaped handle of the present invention; Figure 3 This is a schematic diagram of the internal structure of the rear wheel and motor after assembly of the present invention; The reference numerals in the above drawings are described as follows: 1—stroller frame; 2—Universal wheel; 3—rear wheel; 4—motor; 5—U-shaped handle, 50—upper buckle cover, 51—lower buckle cover, 52—support member, 53—elastic member, 54—limiting plate, 55—positioning column, 56—through hole, 57—limiting plug, 58—limiting groove, 59—top column, 510—opening; 6—Controller; 7—pressing surface; 8—guide column; 9—Return spring. DETAILED DESCRIPTION

[0016] The following describes embodiments of the present invention in detail. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended only to explain the present invention and are not to be construed as limiting the present invention.

[0017] In the description of the present invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "back," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like, indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended only to facilitate the description of the present invention and simplify the description. They do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limiting the present invention. In the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0018] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0019] Reference Figures 1 to 3 As shown, a baby carriage power-assisted walking mechanism based on mechanical linkage pressure sensing includes a frame 1, a front universal wheel 2, a rear wheel 3 and a motor 4 for driving the rear wheel. The frame 1 is provided with a U-shaped handle 5, and the U-shaped handle 5 has a built-in rigid pressure sensor and a controller 6. A pressing surface 7 for pressing the rigid pressure sensor is formed on the surface of the U-shaped handle 5. The rigid pressure sensors are symmetrically distributed on both sides of the U-shaped handle 5, and their sensing surfaces are in contact with the pressing surface 7 through a mechanical linkage structure. The controller 6 is electrically connected to the rigid pressure sensor and the motor 4 respectively, and is used to dynamically adjust the torque and speed of the motor 4 according to the output voltage of the pressure sensor; wherein the rigid pressure sensor is a thin film piezoresistive sensor, its resistance change rate = k = 0.4-0.6Ω / N, and its output voltage range is linearly mapped to the speed of the motor 4.

[0020] The U-shaped handle 5 is detachably assembled from an upper buckle cover 50 and a lower buckle cover 51. The upper buckle cover 50 and the lower buckle cover 51 are provided with a support member 52 and an elastic member 53. The rigid pressure sensor is fixed to the lower buckle cover 51, and its pressure-bearing end contacts the support member 52. The elastic member 53 is supported between the inner wall of the upper buckle cover 50 and the support member 52, and is used to transmit the pressing pressure and reset. The elastic member (53) is pre-compressed by 3mm for installation.

[0021] Specifically, during assembly, a thin film piezoresistive sensor (model FlexiForce A201) is attached to the ceramic substrate of the lower buckle cover (51), and a silicone buffer layer covers the sensing surface of the thin film piezoresistive sensor.

[0022] The lower buckle cover 51 is provided with a positioning column 55, which passes through the through hole 56 of the limiting plate 54. The limiting plate 54 fixes the support member 52 and moves axially between the limiting groove 58 of the positioning column 55 and the limiting plug 57. The inner wall of the upper buckle cover 50 is provided with a top column 59, which is used to press the limiting plug 57 to maintain structural stability.

[0023] The lower buckle cover 51 is provided with a guide column 8, and the guide column 8 is provided with a reset spring 9. The reset spring 9 is a variable pitch spring. The wire diameter of the variable pitch spring is 0.8mm, and the initial pressure is 5N±1N. The two ends of the reset spring 9 respectively abut against the inner wall of the upper buckle cover 50 and the inner wall of the lower buckle cover 51 for automatic reset after pressing.

[0024] The upper buckle cover 50 and the lower buckle cover 51 are connected by a magnetic buckle structure with a magnetic attraction force greater than 8N. The lower buckle cover 51 is provided with an opening 510 in the center for the upper buckle cover 50 to be inserted. During installation, the top column (59) of the upper buckle cover (50) is aligned with the stopper (57), the buckle is inserted into the opening (510) of the lower buckle cover (51), and the return spring (9) is inserted into the guide column (8). After closing, the magnetic attraction force is ≥8N. The controller 6 has a built-in signal processing module for executing the following Figure 3 The control logic shown is as follows: the analog voltage signal of the pressure sensor is converted into a digital signal, and the acceleration curve of the motor 4 is controlled by a PID algorithm.

[0025] The proportional coefficient Kp of the PID algorithm ranges from 0.5 to 1.0, the integral coefficient Ki is 0.05 to 0.15, and the differential coefficient Kd is 0.01 to 0.1.

[0026] This embodiment was verified on a 10° slope: first, the user applied a grip force of 15N → the sensor output voltage was 2.4V; then the controller calculated the target speed: 0.48m / s = 2.4V × 0.2; then the PID algorithm output a 75% duty cycle PWM signal → the motor (4) outputted a torque of 2.5N·m; finally, the stroller ascended at a constant speed of 0.8m / s, and the user measured a thrust of 3N (thrust sensor data).

[0027] In this embodiment, the power supply to the motor is cut off when the following abnormalities are detected: when the pressure value is detected to be greater than 100N (abnormal grip), or when the pressing surface is pressed continuously for more than 30 seconds (to prevent false triggering).

Claims

1. A baby carriage power-assisted walking mechanism based on mechanical linkage pressure sensing, comprising a frame (1), front universal wheels (2), rear wheels (3), and a motor (4) for driving the rear wheels, characterized in that: The frame (1) is provided with a U-shaped handle (5), the U-shaped handle (5) having a built-in rigid pressure sensor and a controller (6), a pressing surface (7) for pressing the rigid pressure sensor is formed on the surface of the U-shaped handle (5), the rigid pressure sensors are symmetrically distributed on both sides inside the U-shaped handle (5), and their sensing surfaces are in contact with the pressing surface (7) through a mechanical linkage structure, and the controller (6) is electrically connected to the rigid pressure sensor and the motor (4) respectively, and is used to dynamically adjust the torque and speed of the motor (4) according to the output voltage of the pressure sensor.

2. The baby stroller power-assisted walking mechanism based on mechanical linkage pressure sensing according to claim 1, characterized in that: The U-shaped handle (5) is detachably assembled from an upper buckle cover (50) and a lower buckle cover (51), wherein the upper buckle cover (50) and the lower buckle cover (51) are provided with a support member (52) and an elastic member (53), wherein the rigid pressure sensor is fixed to the lower buckle cover (51), and its pressure-receiving end contacts the support member (52), and the elastic member (53) is supported between the inner wall of the upper buckle cover (50) and the support member (52) for transmitting pressing pressure and resetting.

3. The baby stroller power-assisted walking mechanism based on mechanical linkage pressure sensing according to claim 2, characterized in that: The lower buckle cover (51) is provided with a positioning column (55), and the positioning column (55) passes through the through hole (56) of the limiting plate (54). The limiting plate (54) fixes the support member (52) and moves axially between the limiting groove (58) of the positioning column (55) and the limiting plug (57). The inner wall of the upper buckle cover (50) is provided with a top column (59) for pressing the limiting plug (57) to maintain structural stability.

4. The baby stroller power-assisted walking mechanism based on mechanical linkage pressure sensing according to claim 3, characterized in that: The lower buckle cover (51) is provided with a guide column (8), and the guide column (8) is provided with a reset spring (9). The reset spring (9) is a variable pitch spring, the wire diameter of the variable pitch spring is 0.8 mm, and the initial pressure is 5N±1N. The two ends of the reset spring (9) respectively abut against the inner wall of the upper buckle cover (50) and the inner wall of the lower buckle cover (51), and are used for automatic reset after pressing.

5. A baby stroller power-assisted walking mechanism based on mechanical linkage pressure sensing according to any one of claims 2 to 4, characterized in that: The upper buckle cover (50) and the lower buckle cover (51) are connected via a magnetic buckle structure, and an opening (510) for the upper buckle cover (50) to be embedded is provided in the center of the lower buckle cover (51).

6. The baby stroller power-assisted walking mechanism based on mechanical linkage pressure sensing according to claim 1, characterized in that: The controller (6) has a built-in signal processing module for executing the control logic shown in FIG3 : converting the analog voltage signal of the pressure sensor into a digital signal and controlling the acceleration curve of the motor (4) through a PID algorithm.

7. The baby stroller power-assisted walking mechanism based on mechanical linkage pressure sensing according to claim 1, characterized in that: The rigid pressure sensor is a thin film piezoresistive sensor, whose resistance change rate = k = 0.4-0.6Ω / N, and whose output voltage range is linearly mapped to the rotation speed of the motor (4).

8. The baby stroller power-assisted walking mechanism based on mechanical linkage pressure sensing according to claim 7, characterized in that: The surface of the rigid pressure sensor is covered with a silica gel buffer layer.

9. The power-assisted walking mechanism according to claim 6, characterized in that: The proportional coefficient Kp of the PID algorithm ranges from 0.5 to 1.0, the integral coefficient Ki ranges from 0.05 to 0.15, and the differential coefficient Kd ranges from 0.01 to 0.1.

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