Assist device and its control method

Abstract

According to this application, an assistive device is used to provide assistance to a vehicle for pushing. The assistive device includes: a pressure sensor for detecting the total weight of the vehicle; a drive device for providing a driving force to the vehicle in the direction of travel; and a control unit, signal-connected to the pressure sensor and the drive device, receiving the total weight detected by the pressure sensor and sending a signal to the drive device to adjust the driving force output by the drive device, such that when the total weight changes, the external force required to drive the vehicle in the direction of travel remains a constant preset force. A control method for the assistive device is also provided.

Description

Technical Field

[0001] This application relates to a power assist device for a children's vehicle, and a control method for the power assist device for the children's vehicle. Background Art

[0002] A stroller is a tool for caring for children. Using a stroller can reduce the physical burden on caregivers and is beneficial to the healthy development of children.

[0003] Reference Figures 1 to 3 The image shows a perspective view of an existing children's vehicle. As shown, the vehicle has a frame and a running gear mounted beneath the frame. The running gear is typically wheels, such as two front wheels and two rear wheels. A handlebar is mounted above the frame. The caregiver can push the vehicle using the handlebar, thus providing propulsion. Clearly, the propulsion force required to drive the vehicle differs depending on the load it carries and / or whether it is going uphill or downhill.

[0004] Currently, there are already children's strollers that offer power assist, such as those using motors to drive the wheels and provide assistance, further reducing the physical burden on caregivers. Most existing power-assisted strollers are controlled by detecting the caregiver's pushing force and maneuvering through handlebars, or by sensing human movement. These methods all rely on signals from sensors on the stroller's platform provided by an external factor to control the power assist system at different speeds.

[0005] Therefore, there is a need to improve the assist function of strollers. For example, it is desirable for the assist device to adjust the assistance based on the load, and also for it to adjust based on the stroller's position, such as going uphill or downhill. Furthermore, it is desirable for the assist device to be more intelligent, so that the caregiver can push the stroller with approximately the same force regardless of the load or the stroller's position. It is also desirable for the assist device to provide an automatic parking function. Summary of the Invention

[0006] According to this application, an assist device is used to provide assistance to a vehicle for pushing. The assist device includes: a pressure sensor for detecting the total weight G of the vehicle; and a drive unit for providing a driving force F to the vehicle in the direction of travel. d The control unit is signal-connected to the pressure sensor and the drive device, receives the total weight G detected by the pressure sensor, and can send a signal to the drive device to adjust the driving force F output by the drive device. d This ensures that when the total weight G changes, the external force required to drive the vehicle in the direction of travel remains a constant preset force F. pre .

[0007] The driving force provided by the drive unit offsets the additional resistance from the load on the vehicle. In this way, whether the vehicle is empty or loaded, the user can push the vehicle with approximately the same preset force.

[0008] In one embodiment, the preset force F pre The thrust required to propel the vehicle when it is unloaded and on a level surface, or an alternative empirical value.

[0009] The preset power is adjustable, and you can choose the preset power based on the usage scenario or user research results to provide a better user experience.

[0010] In one embodiment, the power assist device further includes: a tactile sensor, signal-connected to the control unit, for detecting whether a user is in contact with the vehicle; and a parking device, signal-connected to the control unit, for preventing the vehicle from moving; when the tactile sensor detects that the user is not in contact with the vehicle, the control unit controls the drive device to stop outputting the driving force F. d And activate the parking device to prevent the vehicle from moving.

[0011] An automatically controlled parking device prevents the vehicle from rolling away and causing danger.

[0012] In one embodiment, the drive unit is disposed on the front and / or rear wheels of the vehicle.

[0013] By directly mounting the drive unit on the front and / or rear wheels, the transmission system can be eliminated, reducing the overall weight of the vehicle.

[0014] In one embodiment, the pressure sensor includes a first pressure sensor for detecting the load F1 carried on the platform of the vehicle, wherein the platform is mounted in the middle of the vehicle frame to support the seat; the assist device also includes an angle sensor connected to the control unit for detecting the tilt angle θ of the travel direction relative to the horizontal plane; the control unit calculates the resultant force F required to drive the vehicle in the travel direction based on the total weight G and the tilt angle θ, and adjusts the driving force F of the drive device. d .

[0015] In this embodiment, the driving force output by the drive device can be calculated by measuring only the load and tilt angle, which reduces the computational complexity.

[0016] In one embodiment, the driving force F d Calculated using the following formula:

[0017] F d =FFpre

[0018] F=μGcosθ+Gsinθ

[0019] G = G0 + F1

[0020] Among them, F d F is the driving force of the driving device in the direction of travel, and F is the resultant force driving the vehicle in the direction of travel. pre The preset force required to drive the vehicle in the direction of travel is defined as follows: G is the total weight of the vehicle, G0 is the known empty weight of the vehicle, μ is the empirical resistance constant between the normal force of the vehicle relative to the ground and the frictional resistance, and θ is the angle between the direction of travel and the horizontal plane, which is positive when traveling uphill and negative when traveling downhill.

[0021] The above calculation formula is applicable to both uphill and downhill conditions, and there is no need to switch the calculation formula according to the slope angle.

[0022] In one embodiment, the pressure sensor includes a second pressure sensor and a third pressure sensor; the second pressure sensor is disposed between the platform supporting the seat of the vehicle and the front wheel, and is used to detect a second pressure F2 between the front wheel and the platform; the third pressure sensor is disposed between the platform and the rear wheel, and is used to detect a third pressure F3 between the rear wheel and the platform; the control unit receives the detected second pressure F2 and the third pressure F3, calculates the tilt angle θ of the vehicle's travel direction relative to the horizontal plane based on the second pressure F2 and the third pressure F3, calculates the resultant force F required to drive the vehicle in the travel direction, and adjusts the driving force F of the drive device in the travel direction. d .

[0023] In this embodiment, the tilt angle is no longer measured directly, thus avoiding errors that may be introduced by the tilt angle measuring device.

[0024] In one embodiment, the driving force F d Calculated using the following formula:

[0025] F d =FF pre

[0026] F=μGcosθ+Gsinθ

[0027]

[0028]

[0029] Among them, F dF is the driving force of the driving device in the direction of travel, and F is the resultant force driving the vehicle in the direction of travel. pre The preset force required to drive the vehicle in the direction of travel, G is the total weight of the vehicle, μ is the empirical resistance constant between the normal pressure of the vehicle relative to the ground and the frictional resistance, θ is the angle between the direction of travel and the horizontal plane, θ is positive when traveling uphill and negative when traveling downhill, α is the angle between the line connecting the center of gravity of the front wheel and the platform and the vertical direction of the vehicle, and β is the angle between the line connecting the center of gravity of the rear wheel and the platform and the vertical direction of the vehicle.

[0030] The above formula calculates the vehicle's total weight and tilt angle by using the pressure between the vehicle and the front and rear wheels, thus omitting the need to measure the tilt angle.

[0031] In one embodiment, the vehicle is a stroller.

[0032] The assist device of this application can be advantageously applied to various children's vehicles.

[0033] The beneficial effects of the control method of this application are similar to those of the assistive device, and therefore will not be described in detail.

[0034] According to a control method of an assistive device of this application, the assistive device is used to provide assistance to a vehicle for pushing. The control method includes: detecting the total weight G of the vehicle by a pressure sensor; and providing a driving force F to the vehicle in the direction of travel by a driving device. d The control unit receives the total weight G detected by the pressure sensor and sends a signal to the drive device to adjust the driving force F output by the drive device. d This ensures that when the total weight G changes, the external force required to drive the vehicle in the direction of travel remains a constant preset force F. pre .

[0035] In one embodiment, the preset force F pre The thrust required to move the vehicle when it is unloaded and on a horizontal surface, or an alternative empirical value.

[0036] In one embodiment, the method further includes: detecting whether a user is in contact with the vehicle using a tactile sensor; preventing the vehicle from moving using a parking device; and controlling the drive unit to stop outputting the driving force F when the tactile sensor detects that the user is not in contact with the vehicle. d And activate the parking device to prevent the vehicle from moving.

[0037] In one embodiment, the drive unit is disposed on the front and / or rear wheels of the vehicle.

[0038] In one embodiment, the pressure sensor includes a first pressure sensor for detecting the load F1 carried on the platform of the vehicle, wherein the platform is mounted in the middle of the vehicle frame to support the seat; the assist device also includes an angle sensor for detecting the tilt angle θ of the travel direction relative to the horizontal plane; the control unit calculates the resultant force F required to drive the vehicle in the travel direction based on the total weight G and the tilt angle θ, and adjusts the driving force F of the drive device. d .

[0039] In one embodiment, the driving force F d Calculated using the following formula:

[0040] F d =FF pre

[0041] F=μGcosθ+Gsinθ

[0042] G = G0 + F1

[0043] Among them, F d F is the driving force of the driving device in the direction of travel, and F is the resultant force driving the vehicle in the direction of travel. pre The preset force required to drive the vehicle in the direction of travel is defined as follows: G is the total weight of the vehicle, G0 is the known empty weight of the vehicle, μ is the empirical resistance constant between the normal force of the vehicle relative to the ground and the frictional resistance, and θ is the angle between the direction of travel and the horizontal plane, which is positive when traveling uphill and negative when traveling downhill.

[0044] In one embodiment, the pressure sensor includes a second pressure sensor and a third pressure sensor; the second pressure sensor is disposed between the platform supporting the seat of the vehicle and the front wheel, and is used to detect a second pressure F2 between the front wheel and the platform; the third pressure sensor is disposed between the platform and the rear wheel, and is used to detect a third pressure F3 between the rear wheel and the platform; the control unit receives the detected second pressure F2 and the third pressure F3, calculates the tilt angle θ of the vehicle's travel direction relative to the horizontal plane based on the second pressure F2 and the third pressure F3, calculates the resultant force F required to drive the vehicle in the travel direction, and adjusts the driving force F of the drive device in the travel direction. d .

[0045] In one embodiment, the driving force F d Calculated using the following formula:

[0046] F d =FF pre

[0047] F=μGcosθ+Gsinθ

[0048]

[0049]

[0050] Among them, F d F is the driving force of the driving device in the direction of travel, and F is the resultant force driving the vehicle in the direction of travel. pre The preset force required to drive the vehicle in the direction of travel, G is the total weight of the vehicle, μ is the empirical resistance constant between the normal pressure of the vehicle relative to the ground and the frictional resistance, θ is the angle between the direction of travel and the horizontal plane, θ is positive when traveling uphill and negative when traveling downhill, α is the angle between the line connecting the center of gravity of the front wheel and the platform and the vertical direction of the vehicle, and β is the angle between the line connecting the center of gravity of the rear wheel and the platform and the vertical direction of the vehicle. Attached Figure Description

[0051] The embodiments of this application will be described in detail below with reference to the accompanying drawings, in which:

[0052] Figures 1 to 3 It is a 3D model of a children's vehicle from different angles based on existing technology;

[0053] Figure 4 This is a perspective view of a children's stroller according to the first embodiment of this application;

[0054] Figure 5 This is a perspective view of a children's stroller according to the second embodiment of this application;

[0055] Figure 6 This is a schematic diagram of the electrical connections of the assist device according to this application;

[0056] Figure 7A This is a schematic diagram illustrating the force analysis principle related to gravity when a children's stroller moves on flat ground;

[0057] Figure 7B This is a schematic diagram illustrating the force analysis related to gravity when a children's stroller travels on a slope;

[0058] Figure 8A This is a schematic diagram illustrating the force analysis principle related to the forces acting on the front and rear wheels of a children's stroller when it is moving on flat ground.

[0059] Figure 8B This is a schematic diagram illustrating the force analysis principle related to the forces acting on the front and rear wheels when a children's stroller is moving on a slope.

[0060] List of reference numerals

[0061] 100 Assist Device

[0062] 110 First pressure sensor (total weight sensor)

[0063] 120 Second pressure sensor (front wheel sensor)

[0064] 130 Third pressure sensor (rear wheel sensor)

[0065] 140° angle sensor

[0066] 150 tactile sensors

[0067] 160 drive unit

[0068] 170 Parking device

[0069] 180 Control Unit

[0070] 100 children's strollers

[0071] 200 frame

[0072] 210 car platform

[0073] Z Vertical axis

[0074] F d driving force

[0075] F Resultant force

[0076] F pre Preset force (user-provided driving force)

[0077] G Total weight

[0078] G0 Empty Weight

[0079] F1 First Pressure (Load)

[0080] F2 Second Pressure

[0081] F3 Third Pressure

[0082] μ Empirical resistance constant

[0083] θ Inclination angle

[0084] α First included angle (the angle between the line connecting the front wheel and the frame and the vertical axis of the stroller)

[0085] β Second included angle (the angle between the line connecting the rear wheel and the frame and the vertical axis of the stroller) Detailed Implementation

[0086] While this invention has been illustrated and described with reference to specific embodiments, it should not be limited to the details shown. Rather, various modifications to these details may be made within the scope of equivalents of the claims and without departing from the invention.

[0087] The descriptions of directions such as "front", "back", "up" and "down" used in this document are for ease of understanding only. This invention is not limited to these directions, but can be adjusted according to actual circumstances. Although this application has been described with reference to typical embodiments, the terminology used is illustrative and exemplary, and not restrictive.

[0088] First refer to Figure 4 and Figures 7A to 7B The figure illustrates a first embodiment of a stroller 200 according to this application. As shown, the stroller 200 includes a frame 200 and a power assist device 100 for providing assistance to the stroller 200 for pushing. The power assist device 100 includes a pressure sensor, a drive unit 160, and a control unit 180. In some embodiments, the power assist device 100 may further include a tactile sensor 150 and a parking device 170.

[0089] A pressure sensor detects the total weight G of the stroller 200. The drive unit 160 provides a driving force F to the stroller 200 in the direction of travel. d The control unit 180 is signal-connected to the pressure sensor and the drive unit 160. It receives the total weight G detected by the pressure sensor and can send a signal to the drive unit 160 to adjust the driving force F output by the drive unit 160. d This ensures that when the total weight G changes, the external force required to drive the stroller 200 in the direction of travel remains a constant preset force F. pre .

[0090] For clarity, in this article, the resultant force of all forces driving the child stroller 200 will be referred to as F, and the driving force of the power assist device 100 system will be referred to as F0. d The driving force provided by the user is called F. pre In this application, the driving force provided by the user can be a preset constant force, therefore F preAlso known as preset force. The directions of the resultant force, driving force, and preset force are all parallel to the ground. That is, when the children's bicycle 200 goes uphill or downhill, the angle of inclination of the resultant force, driving force, and preset force changes with the inclination of the ground. In addition, in the formulas in this article, when the values ​​of the resultant force, driving force, and preset force are positive (greater than 0), it means that the direction of the force is the forward direction of the children's bicycle 200. d Preset force F pre When the value is negative (less than 0), it means that the direction of the force is opposite to the forward direction of the children's vehicle 200.

[0091] In one embodiment, the preset force F pre This is the thrust required to push the stroller 200 when it is unloaded and on a level surface. In this case, the calculation formula is F. pre =μ·G0. Where G0 is the empty weight of the children's bicycle 200, and μ is the empirical resistance constant between the normal force and frictional resistance of the children's bicycle 200 relative to the ground. The normal force is the component of the children's bicycle 200's weight perpendicular to the ground; on a horizontal surface, the normal force equals the weight. The empirical resistance constant is the sum of all resistances, including the friction between the bicycle 200's wheels and the ground, and the friction of the wheel bearings.

[0092] In other embodiments, a preset force F pre Other empirical values, such as comfort thrust values ​​shown based on user surveys.

[0093] In an embodiment of the tactile sensor 150 and parking device 170, the tactile sensor 150 is signal-connected to the control unit 180 to detect whether a user is touching the stroller 200. The tactile sensor 150 can be positioned where the user typically touches the stroller 200, such as on the armrest. The parking device 170 is mounted on the wheel, such as on the rear wheel. The parking device 170 is signal-connected to the control unit 180 to prevent the stroller 200 from moving. Specifically, when the tactile sensor 150 detects that the user is not touching the stroller 200, the control unit 180 stops the drive unit 160 and activates the parking device 170 to prevent the stroller 200 from moving.

[0094] In this way, when the user does not touch the stroller 200, the parking device 170 will automatically prevent the stroller 200 from moving, so as to avoid danger caused by the stroller rolling away.

[0095] In one embodiment, a drive unit 160 is mounted on the front and / or rear wheels of the stroller 200. The drive unit 160 can be an electric hub, motor, or other device that provides driving force via electricity. A battery (not shown) located at the bottom of the stroller frame 200 powers the drive unit 160. The drive unit 160 can be a torque motor capable of adjusting the output torque to quantitatively regulate the driving force. For example, a torque motor can quantitatively adjust the driving force based on the magnitude of the input current.

[0096] In this embodiment, the pressure sensor includes a first pressure sensor 110, used to detect the load F1 borne on the platform 210 of the stroller 200. The platform 210 is mounted in the middle of the frame 200 of the stroller 200 to support the seat. The total weight G of the stroller 200 is G0 + F1. It should be understood that G, G0, and F1 are all vertically downwards, not necessarily perpendicular to the ground.

[0097] The assist device 100 also includes an angle sensor 140, which is signal-connected to the control unit 180 to detect the tilt angle θ of the travel direction relative to the horizontal plane. Based on the total weight G and the tilt angle θ, the control unit 180 calculates the resultant force F required to propel the stroller 200 in the travel direction and adjusts the driving force F of the drive unit 160. d .

[0098] Reference 7A to 7B In this embodiment, the driving force F d Calculated using the following formula:

[0099] F d =FF pre

[0100] F=μGcosθ+Gsinθ

[0101] G = G0 + F1

[0102] Where θ is the angle between the direction of travel and the horizontal plane, and according to geometric relationships, θ is also the angle between the direction of gravity and the vertical direction (Z-axis) of the stroller 200. More specifically, when traveling uphill ( Figure 7B The direction of gravity is counterclockwise from the vertical direction of the stroller (200°), at which point θ is positive. According to trigonometric formulas, F is greater than F0 at this point. pre Therefore F d A positive value indicates that the driving force is in the same direction as the forward movement, and the drive unit provides assistance. When traveling downhill (not shown), the direction of gravity is clockwise in the vertical direction (Z-axis) of the child vehicle 200, and θ is negative at this time. According to trigonometric formulas, F is less than F at this time. pre Therefore F dA negative value indicates that the driving force is opposite to the direction of forward movement, and the driving device provides resistance.

[0103] Therefore, given F1, G0, and F pre Given θ and μ, F can be calculated. d .

[0104] Now refer to Figure 5 as well as Figures 8A to 8B A second embodiment according to this application is described.

[0105] The assist device 100 in this embodiment is largely the same as that in the first embodiment, except that it does not include the first pressure sensor 110 and the angle sensor 140. Alternatively, the assist device 100 in this embodiment includes a second pressure sensor 120 and a third pressure sensor 130.

[0106] Specifically, the second pressure sensor 120 is disposed between the frame 210 supporting the seat of the stroller 200 and the front wheel to detect the second pressure F2 between the front wheel and the frame 210. The third pressure sensor 130 is disposed between the frame 210 and the rear wheel to detect the third pressure F3 between the rear wheel and the frame 210. The control unit 180 receives the detected second pressure F2 and third pressure F3, calculates the tilt angle θ of the stroller 200's direction of travel relative to the horizontal plane based on the second pressure F2 and the third pressure F3, calculates the resultant force F required to drive the stroller 200 in the direction of travel, and adjusts the driving force F of the drive unit 160 in the direction of travel. d .

[0107] Thus, in this embodiment, the force detected is the pressure exerted by the platform 210 on the front and rear wheels.

[0108] Reference Figures 8A to 8B In this embodiment, the driving force F d Calculated using the following formula:

[0109] F d =FF pre

[0110] F=μGcosθ+Gsinθ

[0111] θ=α′-α

[0112]

[0113]

[0114] Where α is the angle between the line connecting the center of gravity of the front wheel and the platform 210 on a horizontal surface and the vertical direction of the stroller 200; β is the angle between the line connecting the center of gravity of the rear wheel and the platform 210 on a horizontal surface and the vertical direction of the stroller 200; and α' is the angle between the line connecting the center of gravity of the front wheel and the platform 210 on an inclined surface and the vertical direction of the stroller 200. In this text, the vertical direction of the stroller (vehicle vertical direction) refers to the direction perpendicular to the ground, i.e. Figures 7A to 8B The Z-axis direction is indicated by the label.

[0115] It should be understood that in the above formula, α and β are determined by the structure of the children's vehicle 200 and are independent of the motion state of the children's vehicle 200, and are therefore known values.

[0116] Furthermore, according to the above formula, G needs to be calculated based on α, β, F2, and F3, assuming the stroller 200 is on a level surface. The levelness of the vehicle can be determined based on the ratio of F2 and F3. For example, according to the sine theorem, when F2 / F3 = sinβ / sinα, the stroller 200 is considered to be level. The levelness of the vehicle can also be determined using an additional level or gyroscope (not shown).

[0117] The following describes the operation of the child stroller 200 according to this application.

[0118] When the stroller 200 is on a level surface, if the tactile sensor 150 does not detect a user, the parking device 170 engages, and the wheels cannot turn; if the tactile sensor 150 detects a user, the parking device 170 disengages, the wheels can turn, and the drive unit 160 is activated, providing driving force F. d With a second pressure sensor 120 and a third pressure sensor 130, G is calculated using F2 and F3.

[0119] When the children's bike 200 is going uphill, the operation method is similar to that on level ground.

[0120] When the stroller 200 is going downhill, the component of gravity acts in the same direction as the vehicle's movement, and it may roll away even without any thrust. According to the parking device 170 provided in this application, when the tactile sensor 150 does not detect a user, the parking device 170 is activated, and the wheels cannot turn; when the tactile sensor 150 detects a user, the parking device 170 is deactivated, the wheels can turn, and simultaneously the drive unit 160 is activated, providing a driving force F in the opposite direction of travel. d (This is represented as a negative value in the above calculation formula), at which point the user still needs to use the preset force F. pre Only by pushing the children's stroller 200 can the children's stroller 200 move.

[0121] In one embodiment, the parking device 170 may be an electric braking system used in conjunction with a manual brake (not shown). When the stroller 200 is disconnected from the power supply, the brakes can be manually controlled.

[0122] In summary, this application provides an active power-assisted child stroller, wherein the magnitude of the electric drive power output is controlled by a control unit, allowing the user to push a loaded child stroller with the same thrust as pushing an unloaded stroller, thereby improving the user experience.

[0123] The stroller described in this application is equipped with a tactile sensor that can detect whether the user is holding the stroller. Therefore, the assist function is activated only when the user is using the stroller, and the stroller is locked when the user is not using it to prevent it from rolling away.

[0124] The control method of the children's vehicle according to this application adopts automatic gravity sensing control, which is more stable and effective than human control, thus avoiding misoperation caused by human error.

[0125] This application describes a power assist device and its control method based on a child vehicle; however, it should be understood that the power assist device and its control method of this application can also be applied to other vehicles.

[0126] Since this application can be embodied in various forms without departing from the spirit and substance of this application, it should be understood that the above embodiments are not limited to any of the foregoing details, but should be interpreted in the broadest sense within the scope defined by the claims. Therefore, all variations falling within the scope of the claims or their equivalents should be covered by the claims.

Claims

1. A power-assisting device (100) for providing power assistance to a vehicle for pushing, characterized in that, The assist device (100) includes: A pressure sensor detects the total weight G of the vehicle; The drive unit (160) provides the vehicle with a driving force F in the direction of travel. d ; The control unit (180) is signal-connected to the pressure sensor and the drive device (160), receives the total weight G detected by the pressure sensor, and can send a signal to the drive device (160) to adjust the driving force F output by the drive device (160). d This ensures that when the total weight G changes, the external force required to drive the vehicle in the direction of travel remains a constant preset force F. pre ; The pressure sensor includes a second pressure sensor (120) and a third pressure sensor (130); The second pressure sensor (120) is disposed between the platform (210) of the vehicle for supporting the seat and the front wheel, for detecting the second pressure F2 between the front wheel and the platform (210); The third pressure sensor (130) is disposed between the platform (210) and the rear wheel to detect the third pressure F3 between the rear wheel and the platform (210); The control unit (180) receives the detected second pressure F2 and the third pressure F3, calculates the tilt angle θ of the vehicle's travel direction relative to the horizontal plane based on the second pressure F2 and the third pressure F3, calculates the resultant force F required to drive the vehicle in the travel direction, and adjusts the driving force F of the drive device (160) in the travel direction. d .

2. The assist device (100) according to claim 1, characterized in that: The preset force F pre The thrust required to propel the vehicle when it is unloaded and on a level surface, or an alternative empirical value.

3. The assist device (100) according to claim 1, characterized in that, The assist device (100) also includes: A tactile sensor (150) is signal-connected to the control unit (180) to detect whether the user is in contact with the vehicle; A parking device (170) is signal-connected to the control unit (180) to prevent the vehicle from moving; When the tactile sensor (150) detects that the user is not in contact with the vehicle, the control unit (180) controls the drive device (160) to stop outputting the drive force F. d And activate the parking device (170) to prevent the vehicle from moving.

4. The assist device (100) according to claim 1, characterized in that: The drive unit (160) is mounted on the front and / or rear wheels of the vehicle.

5. The assist device (100) according to claim 4, characterized in that: The pressure sensor includes a first pressure sensor (110) for detecting the load F1 carried on the platform (210) of the vehicle, wherein the platform (210) is mounted on the middle of the frame (200) of the vehicle to support the seat. The assist device (100) also includes an angle sensor (140), which is signal-connected to the control unit (180) to detect the tilt angle θ of the travel direction relative to the horizontal plane; The control unit (180) calculates the resultant force F required to drive the vehicle in the direction of travel based on the total weight G and the tilt angle θ, and adjusts the driving force F of the drive device (160). d .

6. The assist device (100) according to claim 5, characterized in that: The driving force F d Calculated using the following formula: F d =F-F pre F=μGcosθ+Gsinθ G = G0 + F1 Among them, F d F is the driving force of the drive device (160) in the direction of travel, and F is the resultant force driving the vehicle in the direction of travel. pre The preset force required to drive the vehicle in the direction of travel is defined as follows: G is the total weight of the vehicle, G0 is the known empty weight of the vehicle, μ is the empirical resistance constant between the normal force of the vehicle relative to the ground and the frictional resistance, and θ is the angle between the direction of travel and the horizontal plane, which is positive when traveling uphill and negative when traveling downhill.

7. The assist device (100) according to claim 1, characterized in that: The driving force F d Calculated using the following formula: F d =F-F pre F=μGcosθ+Gsinθ Among them, F d F is the driving force of the drive device (160) in the direction of travel, and F is the resultant force driving the vehicle in the direction of travel. pre The preset force required to drive the vehicle in the direction of travel, G is the total weight of the vehicle, μ is the empirical resistance constant between the normal pressure of the vehicle relative to the ground and the frictional resistance, θ is the angle between the direction of travel and the horizontal plane, θ is positive when traveling uphill and negative when traveling downhill, α is the angle between the line connecting the center of gravity of the front wheel and the platform (210) and the vertical direction of the vehicle, and β is the angle between the line connecting the center of gravity of the rear wheel and the platform (210) and the vertical direction of the vehicle.

8. The assist device (100) according to claim 1, characterized in that: The vehicle is a children's stroller (200).

9. A method for controlling an assist device (100), said assist device (100) for providing assistance to a vehicle for pushing, characterized in that, The control method includes: The total weight G of the vehicle is detected by a pressure sensor; The vehicle is provided with a driving force F in the direction of travel by the drive device (160). d ; The control unit (180) receives the total weight G detected by the pressure sensor and sends a signal to the drive device (160) to adjust the driving force F output by the drive device (160). d This ensures that when the total weight G changes, the external force required to drive the vehicle in the direction of travel remains a constant preset force F. pre ; The pressure sensor includes a second pressure sensor (120) and a third pressure sensor (130); The second pressure sensor (120) is disposed between the platform (210) of the vehicle for supporting the seat and the front wheel, for detecting the second pressure F2 between the front wheel and the platform (210); The third pressure sensor (130) is disposed between the platform (210) and the rear wheel to detect the third pressure F3 between the rear wheel and the platform (210); The control unit (180) receives the detected second pressure F2 and the third pressure F3, calculates the tilt angle θ of the vehicle's travel direction relative to the horizontal plane based on the second pressure F2 and the third pressure F3, calculates the resultant force F required to drive the vehicle in the travel direction, and adjusts the driving force F of the drive device (160) in the travel direction. d .

10. The control method according to claim 9, characterized in that: The preset force F pre The thrust required to move the vehicle when it is unloaded and on a horizontal surface, or an alternative empirical value.

11. The control method according to claim 9, characterized in that, The method further includes: The tactile sensor (150) detects whether the user is in contact with the vehicle; The vehicle is prevented from moving by the parking device (170); When the tactile sensor (150) detects that the user is not in contact with the vehicle, the control unit (180) controls the drive device (160) to stop outputting the drive force F. d And activate the parking device (170) to prevent the vehicle from moving.

12. The control method according to claim 9, characterized in that: The drive unit (160) is mounted on the front and / or rear wheels of the vehicle.

13. The control method according to claim 12, characterized in that: The pressure sensor includes a first pressure sensor (110) for detecting the load F1 carried on the platform (210) of the vehicle, wherein the platform (210) is mounted on the middle of the vehicle frame for supporting the seat. The assist device (100) further includes an angle sensor (140) for detecting the angle θ of the travel direction relative to the horizontal plane; The control unit (180) calculates the resultant force F required to drive the vehicle in the direction of travel based on the total weight G and the tilt angle θ, and adjusts the driving force F of the drive device (160). d .

14. The control method according to claim 13, characterized in that: The driving force F d Calculated using the following formula: F d =F-F pre F=μGcosθ+Gsinθ G = G0 + F1 Among them, F d F is the driving force of the drive device (160) in the direction of travel, and F is the resultant force driving the vehicle in the direction of travel. pre The preset force required to drive the vehicle in the direction of travel is defined as follows: G is the total weight of the vehicle, G0 is the known empty weight of the vehicle, μ is the empirical resistance constant between the normal force of the vehicle relative to the ground and the frictional resistance, and θ is the angle between the direction of travel and the horizontal plane, which is positive when traveling uphill and negative when traveling downhill.

15. The control method according to claim 9, characterized in that: The driving force F d Calculated using the following formula: F d =F-F pre F=μGcosθ+Gsinθ Among them, F d F is the driving force of the drive device (160) in the direction of travel, and F is the resultant force driving the vehicle in the direction of travel. pre The preset force required to drive the vehicle in the direction of travel, G is the total weight of the vehicle, μ is the empirical resistance constant between the normal pressure of the vehicle relative to the ground and the frictional resistance, θ is the angle between the direction of travel and the horizontal plane, θ is positive when traveling uphill and negative when traveling downhill, α is the angle between the line connecting the center of gravity of the front wheel and the platform (210) and the vertical direction of the vehicle, and β is the angle between the line connecting the center of gravity of the rear wheel and the platform (210) and the vertical direction of the vehicle.

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