KR102366931B1 - Electric assist module and detection method of the entry section of flat land - Google Patents

Abstract

The present invention provides an electric assist module detachable from a wheelchair frame provided with a seating portion for a occupant to sit on a frame having a footrest and a handle and provided with driving wheels on both sides of the frame, wherein a plurality of wheels and the wheels are rotated As a caterpillar-type traveling member provided with a chain belt, the caterpillar part is mounted on the wheelchair frame and ascends and descends stairs or steps of the wheelchair frame; a landing gear unit provided in the caterpillar unit, the free ends of which are raised/lowered before and after the center of gravity of the wheelchair frame as an axis; and a pressure sensing unit provided on a lower surface of the caterpillar unit, wherein the pressure sensing unit detects a pressure change in the caterpillar unit to determine the last section of the step (stair-level entry section).

Description

Electric assist module capable of detecting a section entering flat ground {ELECTRIC ASSIST MODULE AND DETECTION METHOD OF THE ENTRY SECTION OF FLAT LAND}

The present invention relates to an electric assist module that assists in inclining driving of a wheelchair, and in particular, it is possible to drive a wheelchair through stairs or steps without an assistant by a passenger's manipulation, and an electric assist capable of detecting the last section of the step, the level entry section It's about modules.

A wheelchair has a structure in which a chair is provided with wheels so that it can be moved in a seated state for a person who does not have free legs or who has difficulty walking due to physical discomfort. Recently, due to the rapid aging of the population and the increase in the number of people with walking disabilities, the number of people with disabilities in transportation has dramatically increased. Accordingly, the demand for wheelchairs, which are the main means of transportation for the transportation disadvantaged, is increasing, and the desire to use wheelchairs in various environments is increasing.

Among those who answered that they felt uncomfortable when going out using a wheelchair, 20.8% had jaws and 20% had stairs. Wheelchair users must use a separate elevator or lift to move on stairs and slopes. However, the size and weight of the existing electric wheelchair limit the use of a lift, and in the case of a building that does not have an elevator or lift installed, it is inconvenient that the guardian must lift the user to move the stairs. In addition, although there are cases where a separate slope or lift is installed as a solution to the movement of stairs, additional costs are charged because they must be installed on each main movement path, and installation is difficult due to structural problems. Therefore, in order to secure the mobility rights of wheelchair users, there is a need to develop a device that can climb on its own regardless of location or guardian and can move on stairs by simply attaching it to a manual wheelchair.

Examples of devices that allow wheelchair users to climb stairs on their own are the wheel-type iBot, and the caterpillar-type Scelovo and Topchair. A wheel-type stair climbing device such as the iBot runs the stairs with precise balance control in the form of an inverted pendulum. However, due to the inability to stand up due to power cut off while driving on the stairs. Safety accidents such as overturning may occur. Therefore, in most of the studies on the development of devices for safe stair climbing, studies using a caterpillar-type mechanism rather than a general wheel are being conducted in parallel. Since the caterpillar-type mechanism has excellent contact performance with curved surfaces and the grounding area is evenly distributed, stable driving is possible in climbing obstacles or stairs compared to other driving methods.

In the case of previous studies, studies on the caterpillar mechanism were focused on stable stair entry and stair climbing, but studies on exceptional situations that may occur during driving are insufficient. In particular, yawing such as misalignment during stair driving may occur due to external factors such as slippage and slippery ground. Yawing loses straightness and causes a phenomenon of driving biased to one side, and it can lead to safety accidents such as overturning, so there is a high need for research.

On the other hand, as a prior art, US Patent No. 7080842 discloses a wheelchair device for stairs. The prior art up to now has a pivot member for landing on the step, but an assistant is required due to safety accidents such as overturning when climbing the stairs. Currently, a wheelchair and auxiliary aid module for stair lifts that are commercially available include SANO's lift car PTR. Currently, a caterpillar-type product that is applied to a wheelchair and enables the wheelchair to travel up the stairs is also being released, but safety issues such as overturning have not been solved because the liftcar's unique function helps the wheelchair go up and down the stairs alone without an assistant.

In addition, the electric assist module for the caterpillar mechanism wheelchair detects the stairs and secures the angle of entry using the landing gear. In the last step, stair-flat entry, if the device does not detect the edge of the last step and the center of gravity passes the edge of the last step, the weight of the device is concentrated, which may lead to a large impact and damage to the device. In the conventional electric assist module for stair climbing, vision sensors such as lidar, ultrasonic, and infrared are used for position estimation. However, due to the characteristics of the stair lift device, it is difficult to attach the sensor to a high position, and it is arranged very close to the stairs, so it is not easy to identify the stairs.

Accordingly, the present applicant has devised an electric assist module that senses the stairs-flat entry section with a sensing technique that is strong in the external environment and is easy to detect immediately.

US Patent No. 7080842

An object of the present invention is to provide an electric assist module that enables the driving of stairs and step elevation of a wheelchair without an assistant.

In addition, an object of the present invention is to provide an electric assist module capable of detecting a step-flat entry section using a sensing technique that is robust to the external environment and is easy to detect immediately by using a pressure sensor.

In order to achieve the above object, the present invention provides an electric assist module that is provided with a seating portion for a passenger to sit on a frame having a footrest and a handle, and is detachable from a wheelchair frame provided with driving wheels on both sides of the frame, a plurality of As a caterpillar type traveling member provided with a wheel and a chain belt for rotating the wheel, the caterpillar part is mounted on the wheelchair frame to elevate the stairs or steps of the wheelchair frame; a landing gear unit provided in the caterpillar unit, the free ends of which are raised/lowered before and after the center of gravity of the wheelchair frame as an axis; and a pressure sensing unit provided on a lower surface of the caterpillar unit, wherein the pressure sensing unit detects a pressure change in the caterpillar unit to determine the last section of the step (stair-level entry section).

Preferably, the pressure sensor may include a first pressure sensor provided at a front position of the caterpillar unit and a second pressure sensor provided at a rear position of the caterpillar unit.

Preferably, the caterpillar unit, a sensor groove for accommodating the pressure sensing unit is formed on a lower surface thereof, and an elastic member for providing elasticity in the height direction and a plurality of pressure sensors for sensing the pressure of the elastic member are accommodated in the sensor groove. can

Preferably, the control unit may further include a control unit that determines whether the caterpillar unit enters the flat ground using the measured pressure data of the pressure sensing unit.

Preferably, the control unit, after the pressure is sensed in the rear of the caterpillar part through the pressure sensing part, when the pressure is sensed in the front, the caterpillar part is determined to be in a stairway running state, and the pressure in the front and rear of the caterpillar part After this is sensed, when no pressure is sensed in the front, it is determined that the stairs have entered the flat section, and the landing gear unit may be lowered.

Preferably, a wheelchair angle adjusting unit fastened to the wheelchair frame in the rear region of the caterpillar unit and tilting the wheelchair frame to maintain the seating unit horizontally when ascending/lowering the stairs of the caterpillar unit may be further included.

Preferably, the wheelchair angle adjusting unit includes: a tilting frame having one end detachably coupled to a frame forming a backrest of the wheelchair frame and the other end detachably coupled to a seat portion or a lower frame of the seat portion of the wheelchair frame; and a tilting module having a well-known power means capable of pivoting or rotating the tilting frame at a predetermined angle based on the caterpillar unit.

According to the present invention, the caterpillar part of the caterpillar track linearly raises and lowers the step of the stairs, and a separate landing gear part for the initial landing of the caterpillar part is provided, so that it is possible to ascend and descend the stairs of the wheelchair without an assistant. In addition, the landing gear part has free ends at the front and rear, and raises and lowers the front/rear based on the center of gravity. In case of successive step rises such as stairs, the center of gravity is positioned toward the stairs to enable stable driving to prevent falls by running backwards. do. In addition, there is an advantage of assisting the user so that the user can properly respond according to the type of the step by looking at the step in the front and ascending and descending from the obstacle of the hill, such as a step difference of one step rather than the stairs.

According to the present invention, without an expensive vision sensor, the stair-flat entry section can be detected with a sensor mechanism that is robust to the external environment and capable of immediate detection, and the landing gear is lowered to allow safe entry into the flat ground during the entry process. There is an improvement advantage.

1 shows a perspective view in which an electric assist module according to an embodiment of the present invention is coupled to a wheelchair frame.
Figure 2 shows the driving state of the electric assist module according to an embodiment of the present invention.
3 is a perspective view of a wheelchair in which an electric assist module is coupled to a wheelchair frame according to another embodiment of the present invention. Figure 3 (a) shows the appearance of the electric assist module and the wheelchair frame on a flat ground, Figure 3 (b) shows the appearance of the electric assist module and the wheelchair frame when climbing stairs.
Figure 4 shows a rear perspective view of the electric assist module according to the embodiment of Figure 3;
5 shows a landing state of the electric assist module according to the embodiment of FIG.
6 shows an electric assist module according to another embodiment of the present invention. Figure 6a shows a side view of the electric assist module, Figure 6b is the electric assist module stairs - shows a plane entry state.
7 shows an algorithm for detecting a flat ground entry section of the electric assist module according to the embodiment of FIG. 6 .
8 shows an experimental example environment of the electric assist module according to the embodiment of FIG.
9 shows data of the front and rear pressure sensors according to the experimental example of FIG. 6 .
FIG. 10 shows the experimental process and results of the experimental example of FIG. 6 .

Hereinafter, the present invention will be described in detail with reference to the contents described in the accompanying drawings. However, the present invention is not limited or limited by the exemplary embodiments. The same reference numerals provided in the respective drawings indicate members that perform substantially the same functions.

Objects and effects of the present invention can be naturally understood or made clearer by the following description, and the objects and effects of the present invention are not limited only by the following description. In addition, in the description of the present invention, if it is determined that a detailed description of a known technology related to the present invention may unnecessarily obscure the gist of the present invention, the detailed description thereof will be omitted.

1 shows a perspective view of a wheelchair 1 in which an electric assist module 3 according to an embodiment of the present invention is coupled to a wheelchair frame 10 .

Referring to FIG. 1 , the wheelchair 1 according to the present embodiment capable of ascending and descending stairs and steps may include a wheelchair frame 10 and an electric assist module 3 . The wheelchair frame 10 is provided with a seating portion 13 on which a passenger sits on the frame 11 having a footrest and a handle, and driving wheels 15 are provided on both sides of the frame 11 . The electric assist module 3 according to the present embodiment may be supplied by being integrally coupled to the wheelchair frame 10 , or may be supplied separately to be compatible with the wheelchair frame 10 .

The electric assist module 3 is fastened to the lower part of the wheelchair frame 10 . Preferably, the electric assist module 3 may be provided by being fastened to the space between the left and right driving wheels 15 . The electric assist module 3 does not interfere with the driving of the driving wheels 15 on flat ground, but assists the occupant to drive on a slope or a single step of a staircase or sidewalk block.

The electric assist module 3 may include a caterpillar unit 30 , a landing gear unit 50 , and a control unit 70 . In the electric assist module 3 , when one end of the landing gear unit 50 is raised and lowered, the caterpillar unit 30 is raised and lowered by reaction force so that the stairs or step surface and the caterpillar unit 30 come into contact with each other. Thereafter, the step is driven by the driving of the caterpillar unit 30 so that the stairs or the slope of the step of the wheelchair frame 10 can be raised and lowered without an assistant.

The caterpillar unit 30 is a caterpillar type traveling member provided with a plurality of wheels 31 and a chain belt 33 for rotating the wheels 31 , and is mounted on the wheelchair frame 10 and is a step of the wheelchair frame 10 . Or raise and lower the step.

In this embodiment, the caterpillar unit 30 is a wheel that travels up and down the stairs of the wheelchair frame 10 and is distinguished from the driving wheel 15 . Driving when ascending and descending stairs is performed by the caterpillar unit 30 . The caterpillar part 30 is a caterpillar-type traveling member consisting of a wheel 31 and a chain belt 33. Even without precise balance control in the inverted pendulum shape of the driving wheel 15-type stair climbing device, the curved surface contact performance is excellent. It is excellent and has the characteristic that the grounding area is evenly distributed. The caterpillar part 30 of the caterpillar track type is particularly excellent for climbing stairs because the chain belt 33 provides a continuous running surface in the stairs having a continuous step. On the other hand, several studies have focused on stable stair entry and stair climbing of the caterpillar mechanism, but studies on exceptional situations that may occur during driving are insufficient. In particular, yawing, such as misalignment behavior during stair driving, may cause a phenomenon of losing straightness and driving biased to one side, which may lead to safety accidents such as overturning. Accordingly, in the present embodiment, the landing gear unit 50 is configured as a means for stably entering the stairs of the caterpillar unit 30 . In addition, the control unit 70 in which the logic of driving control for stable driving of the caterpillar unit 30 is mounted may be included.

The landing gear unit 50 is provided in the caterpillar unit 30 , and the free ends of the front/rear sides may be raised/lowered around the center of gravity of the wheelchair frame 10 as an axis. The landing gear unit 50 means an auxiliary member for the initial elevation of the caterpillar unit 30 . It is noted that the landing gear unit 50 according to the present embodiment is provided with a gear structure capable of elevating the front or the rear, respectively, based on the wheelchair. When ascending and descending stairs in a wheelchair without an assistant, safety accidents such as falls can be prevented by driving the user to face the rear to ascend and descend with the back of the stairs. Therefore, it is preferable that the landing gear unit 50 is provided to lift the front or rear of the wheelchair so that the front or rear of the wheelchair can be driven separately according to the type of step.

The landing gear unit 50 may include a gear shaft 51 , a front landing wheel 53 , a rear landing wheel 55 , and a driving module 57 .

The landing gear unit 50 is controlled so that the front free end is raised and lowered in a state in which the direction of the wheelchair frame 10 is switched to the reverse direction so that the passenger can have his or her back on the stairs when ascending and descending the stairs. In addition, the landing gear unit 50 is controlled so that the free end of the rear is raised and lowered in a state in which the direction of the wheelchair frame 10 is positioned in the front so that the passenger faces the front when the step is lifted. The landing gear unit 50 may be controlled so that the occupant travels the stepped terrain in a straight line when ascending and descending by a single step, and the passenger travels the stepped terrain in a reverse manner when ascending and descending by a plurality of steps of the stairs.

The gear shaft 51 is located at the center of gravity of the wheelchair frame 10 . Referring to FIG. 2 , the gear shaft 51 is provided under the caterpillar unit 30 , and provided on both sides with a DC motor driving the gear in the center. The gear shaft 51 may be provided as a parallel frame as shown in FIG. 2 , but may also be provided as a single frame.

The front landing wheel 53 and the rear landing wheel 55 are provided on a body having a length extending in the front-rear direction about the gear shaft 51 . The front landing wheel 53 and the rear landing wheel 55 are provided with wheels at the ends of the body, respectively, and can be driven complementary to each other.

The driving module 57 may include a motor to selectively elevate the front landing wheel 53 or the rear landing wheel 55 around the gear shaft 51 to elevate one side of the caterpillar unit 30 . The driving module 57 may be located at the rear of the caterpillar unit 30 and connected to the rear landing wheel 55 .

The front landing wheel 53 and the rear landing wheel 55 are disposed under the caterpillar part 30, and when the front landing wheel 53 is raised and lowered, the rear end of the caterpillar part 30 is raised and lowered, and the rear landing wheel 55 ), the front end of the caterpillar unit 30 is raised and lowered when the lift.

The driving module 57 may raise and lower the front landing wheel 53 when ascending and descending stairs, and may raise or lower the rear landing wheel 55 when ascending or descending a step other than stairs.

The control unit 70 controls the landing gear unit 50 to enable stable stair elevation of the caterpillar unit 30 .

Figure 2 shows the driving state of the electric assist module (3) according to an embodiment of the present invention. In Fig. 2, the step at which the wheelchair frame 10 ascends and descends illustrates a staircase 8 having a large continuous step and a sidewalk block 9 having a single step.

Fig. 2 (a) is a view showing the control unit 70 controlling the electric assist module 3 when ascending and descending the stairs 8 . The control unit 70 rotates the wheelchair frame 10 when entering the stairs 8 of successive steps so that the seated person has their back to the stairs. Thereafter, the control unit 70 presses the rear landing wheel 55 of the landing gear unit 50 toward the ground, and lifts the front landing wheel 53 . Accordingly, the rear of the caterpillar part 30 is lifted around the gear shaft 51, and the wheelchair frame 10 is laid down in the rear direction. When the wheelchair frame 10 is seated on the first step while maintaining the stability of the center of gravity, the caterpillar unit 30 is then driven to elevate the continuous step surface.

Figure 2 (b) is, the control section 70 is a control state of the electric assist module (3) when the walkway block (9) lifting. When the control unit 70 enters the sidewalk block 9 of a single step, the risk of overturning of the wheelchair is weak, so that the control unit 70 enters the forward state without a rotation operation as in (a) of FIG. 3 . The control unit 70 presses the front landing wheel 53 of the landing gear unit 50 toward the ground and lifts the rear landing wheel 55 . Accordingly, the front of the caterpillar part 30 is lifted around the gear shaft 51 and is seated on the step difference of the sidewalk block 9 .

3 is a perspective view of a wheelchair in which the electric assist module 3 is coupled to the wheelchair frame 10 according to another embodiment of the present invention. Fig. 3 (a) shows the electric assist module 3 and the wheelchair frame 10 on flat ground, and Fig. 3 (b) is the electric assist module 3 and the wheelchair frame 10 when climbing stairs. shows the appearance of

Referring to FIG. 3 , the electric assist module 3 may include the caterpillar unit 30 , the landing gear units 50 and 500 , and the control unit 70 described above in FIGS. 1 to 2 . The electric assist module 3 of FIG. 3 may further include a wheelchair angle adjusting unit 40 as an embodiment different from those of FIGS. 1 and 2 . In the embodiment of FIGS. 1 and 2 , when the electric assist module 3 assists in climbing the stairs, the ascending direction is changed to maintain the center of gravity of the wheelchair frame 10, and depending on the ascending direction, in the direction of the front part or the rear part A landing gear unit 50 capable of landing was presented. In the present embodiment according to FIG. 3 , the configuration of the wheelchair angle adjusting unit 40 is added so that the wheelchair frame 10 does not tilt when climbing stairs.

Hereinafter, the configuration of another embodiment of the electric assist module 3 according to FIG. 3 will be described in detail. In the present embodiment, the caterpillar unit 30 may be provided as a 'B'-shaped frame in which the body on which the wheelchair frame 10 is seated is formed to a predetermined length and bent upward at the rear of the body. The wheelchair angle adjusting unit 40 may be provided in the bent rear region of the caterpillar unit 30 , and the wheelchair frame 10 may be tilted about the wheelchair angle adjusting unit 40 as an axis.

The wheelchair angle adjusting unit 40 may include a tilting frame 41 and a tilting module 43 . One end of the tilting frame 41 may be detachably coupled to a frame forming a backrest of the wheelchair frame 10 , and the other end may be detachably coupled to a seat portion or a lower frame of the seat portion of the wheelchair frame 10 . The tilting frame 41 may be pivoted by a predetermined angle by the rotational force of the tilting module 43 . The wheelchair frame 10 coupled to the tilting frame 41 may be tilted by the pivot of the tilting frame 41 .

The angle adjustment of the wheelchair angle adjustment unit 40 may be performed through the control unit 70 . The control unit 70 is provided with a PID control module to control the landing gear units 50 and 500 when the stairs are detected for stair travel, and the angle calculated when the landing gear units 50 and 500 is controlled is offset. It is possible to calculate the tilting angle of the wheelchair angle adjusting unit 40 so that the

The tilting module 43 is located at the rear of the wheelchair frame 10, and is provided in the caterpillar unit 30 and may include a known motor configuration that can be pivoted or rotated at a predetermined angle based on the caterpillar unit 30. there is. One end of the tilting module 43 is coupled to the tilting frame 41 .

4 shows a rear perspective view of the electric assist module 3 according to the embodiment of FIG. Referring to FIG. 4 , the electric assist module 3 according to the embodiment of FIG. 3 may include a landing gear unit 500 equipped with an omni wheel 530 . In the landing gear unit 500 according to the present embodiment, the landing gear shaft 510 may be provided in the width direction of the caterpillar unit 30 . The landing gear unit 500 according to the present embodiment is different from the embodiment of FIGS. 1 and 2 , and the landing wheel may be formed only on one side instead of both sides of the front and rear. This is because the center of gravity of the wheelchair frame 10 can be stably maintained by the configuration of the wheelchair angle adjustment unit 40 described above, so that the climbing direction may be configured only on one side, not on both sides.

In this embodiment, it is preferable that the omni wheel 530 is provided as the wheel of the landing gear unit 500 . The omni wheel 530 is an auxiliary wheel whose frame is rotated in the front-rear direction of the wheelchair frame 10, and is rotated laterally on the outer periphery of the frame in which the wheelchair frame 10 is rotated in the front-rear direction. A plurality of 531 may be configured.

When the caterpillar unit 30 is configured as an aid module for climbing stairs of the wheelchair, the front and rear driving of the wheelchair can be easily controlled, but the turning operation becomes difficult due to the volume of the caterpillar unit 30 . In order to improve the landing gear unit 500 according to the present embodiment, the omni wheel 530 may be applied as a landing wheel. Due to the auxiliary wheel 531 of the omni wheel 530, the caterpillar unit 30 can be easily rotated.

5 shows a landing state of the electric assist module 3 according to the embodiment of FIG. Referring to FIG. 5 , when ascending stairs or turning in the direction of the electric assist module 3, the landing gear unit 500 is driven to lower the omni wheel 530, and it can be seen that the caterpillar unit 30 is lifted. . In this case, the occupant may drive so that the caterpillar unit 30 climbs the stairs or may turn in the direction of the caterpillar unit 30 .

6 shows an electric assist module 3 according to another embodiment of the present invention. Figure 6a shows a side view of the electric assist module (3), Figure 6b shows the steps of the electric assist module (3) - flat entry state. Referring to Figure 6, the electric assist module 3 according to the present embodiment is provided with a seating portion on which a passenger sits on a frame having a footrest and a handle, and a wheelchair frame 10 equipped with driving wheels on both sides of the frame. is detached from

The electric assist module 3 according to the present embodiment may include a caterpillar unit 30 , a landing gear unit 50 , a wheelchair angle adjusting unit 40 , a control unit 70 , and a pressure sensing unit 80 . The landing gear unit 50 and the control unit 70 are omitted for convenience of description, and may be applied in the same manner as in the embodiments of FIGS. 1 to 5 .

The caterpillar part 30 is a caterpillar-type traveling member provided with a plurality of wheels 31 and a chain belt 33 for rotating the wheels 31, and is mounted on the wheelchair frame 10 to provide steps or steps of the wheelchair frame. to elevate The caterpillar unit 30 is provided with a belt support 35 as a frame, and a chain belt 33 is coupled to the belt support 35 to constitute an endless track.

The caterpillar unit 30 may have a sensor groove 351 accommodating the pressure sensing unit 80 on the lower surface thereof. In this embodiment, the sensor groove 351 may be formed in the belt support 35 of the caterpillar unit 30, and at least two may be formed by being spaced apart by a predetermined distance on the lower surface of the belt support 35. . One sensor groove 351 may be formed on the lower surface of the belt support 35 at a position in front of the caterpillar unit 30 and one at a position at the rear of the caterpillar unit 30 .

The sensor groove 351 accommodates the pressure sensors 81 and 83 to be described later before and after the caterpillar unit 30, respectively, at the front and rear of the caterpillar unit 30. When passing the edge of the step 8, the pressure to detect The sensor groove 351 may accommodate an elastic member 801 that provides elasticity in the height direction and a plurality of pressure sensors 803 that sense the pressure of the elastic member 801 .

The landing gear unit 50 is provided in the caterpillar unit 30 , and the free ends of the front/rear sides may be raised/lowered around the center of gravity of the wheelchair frame 10 as an axis. As an embodiment of the landing gear unit 50, the above-mentioned matters in FIGS. 1 to 5 may be used.

The wheelchair angle adjusting unit 40 is fastened to the wheelchair frame 10 in the rear region of the caterpillar unit 30, and when the caterpillar unit 30 goes up/down the stairs, the wheelchair frame 10 is tilted to horizontal the seating area. can be maintained as The wheelchair angle adjusting unit 40 may include a tilting frame 41 and a tilting module 43 .

One end of the tilting frame 41 may be detachably coupled to a frame forming a backrest of the wheelchair frame 10 , and the other end may be detachably coupled to a seat portion or a lower frame of the seat portion of the wheelchair frame 10 . The tilting module 43 may include a well-known power means capable of pivoting or rotating the tilting frame 41 at a predetermined angle with respect to the caterpillar unit 30 .

The pressure sensing unit 80 may be provided on the lower surface of the caterpillar unit 30 . The pressure sensing unit 80 may be provided on the lower surface of the belt support 35 of the caterpillar unit 30 . The pressure sensing unit 80 may be accommodated in the sensor groove 351 formed on the lower surface of the belt support 35 of the caterpillar unit 30 . The pressure sensing unit 80 detects a pressure change in the caterpillar unit 30 to determine the last section of the step (stair-level entry section).

The electric assist module 3 according to this embodiment does not use an expensive lidar sensor, but checks the last step of the stairs from the pressure detection algorithm on the floor, so that it is possible to ascend and descend the stairs at a low cost and to travel stably.

The pressure sensor 80 may include a first pressure sensor 81 and a second pressure sensor 83 . The first pressure sensor 81 may be provided at a front position of the caterpillar unit 30 . The second pressure sensor 83 may be provided at a rear position of the caterpillar unit 30 .

The first pressure sensor 81 detects the edge of the stairs when ascending/lowering the stairs from the front of the caterpillar unit 30 . The second pressure sensor 83 detects the edge of the stairs when ascending/lowering the stairs from the rear of the caterpillar unit 30 . The first and second pressure sensors 81 and 83 may be provided in the sensor groove 351 by modularizing the elastic member 801 and the pressure sensor 803, respectively.

The control unit 70 may determine whether the caterpillar unit 30 enters the flat ground by using the measured pressure data of the pressure sensing unit 80 .

After the pressure is sensed in the rear of the caterpillar unit 30 through the pressure sensing unit 80, the control unit 70, when the pressure is sensed in the front, the caterpillar unit 30 can be determined to be in the running state. .

After the pressure is sensed at the front and rear of the caterpillar unit 30, the control unit 70 determines that the wheelchair has entered the flat section from the stairs and lowers the landing gear unit 50 when no pressure is sensed at the front. can do it

This embodiment of FIG. 6 is characterized in that the configuration of the pressure sensing unit 80 for step edge detection is added to the configuration of the electric assist module 3 described above in the embodiment of FIG. 3 .

7 shows an algorithm for detecting a flat ground entry section of the electric assist module 3 according to the embodiment of FIG. 6 . 8 shows an experimental example environment of the electric assist module 3 according to the embodiment of FIG.

In this experimental example, the position of the pressure sensing unit 80 was designed to be positioned one at the front and one at the rear of the belt support 35 so as to detect up to two corners of the stairs during stair travel. The pressure sensor 80 is designed so that the pressure sensors 81 and 83 are positioned at the corners of the steps with a difference of one space, based on the step width and step height, which are the ranges suggested by Ordinance No. 548 of the Ministry of Land, Infrastructure and Transport. In addition, in order to be applicable to a wide range of stairs, the pressure sensing unit 80 is designed to sense a wide range of pressure by designing a wide sensing area of the pressure sensors 81 and 83 .

An experiment was conducted by applying the pressure sensor-based stair-flat position estimation technique to the stair hoisting device for wheelchairs. As for the experimental environment, the effective width of stairs and landings, which is within the range suggested by Ordinance of the Ministry of Land, Infrastructure and Transport No. 548, was manufactured to be 60 mm or more, the step height was 180 mm or less, and the step width was 260 mm or more.

In the experiment, start running the stairs with the stair hoisting device ringing on the edge of the stairs (1), and lower the landing gear (50) to enter the flat ground when the stairs (4) sense the entry section to the flat ground. As a result of the experiment, the data of the front and second pressure sensors 83 are shown in FIG. 9 .

Referring to FIG. 7 , the algorithm for detecting the flat land entry section of the controller 70 is as follows. During stair driving (ⓐ), the pressure sensors 81 and 83 continuously sense the pressure to determine whether to move on the edge of the stairway (ⓑ). If pressure is applied to the front belt support 35 after (ⓒ), it can be seen that both pressure units are located at the edge of the stairs and are running up the stairs. If pressure is not applied to the front support 35 after the pressure is sensed on the rear belt support 35 (ⓓ), it is determined as a staircase-flat entry section (ⓒ.ⓓ). When the position of the stair lift device of the pressure sensing unit 80 is estimated to be the level entry section, the landing gear 50 is lowered (ⓔ) to enter the flat ground.

9 shows data of the front and rear pressure sensors 80 according to the experimental example of FIG. 6 . When moving over the edge of the stairs while driving, the pressure was sensed at the rear pressure sensor and then at the front pressure sensor (①-②,②-③,③-④). However, when moving on the stairs-flat entry section, pressure was sensed in the rear pressure sensor and then no pressure was detected in the front pressure sensor, so it was judged as the last step edge. After determining the last stair edge, the landing gear was lowered to perform the motion to enter the flat ground.

FIG. 10 shows the experimental process and results of the experimental example of FIG. 6 .

As a result of applying the detection technique to the level entering section, a maximum acceleration of 0.5 [g] was detected when entering the flat ground, and an acceleration of up to 1.15 [g] was detected when the device weight drifted before application. As a result of the experimental example, the test result showed that after the application of the detection technique for the entry section, the electric assist module (3) decreased the maximum acceleration for entering the flat ground from 1.1 [g] to 0.5 [g], and the safety increased according to the reduction in the amount of impact by 47.8%. Confirmed.

Although the present invention has been described in detail through representative embodiments above, those of ordinary skill in the art to which the present invention pertains will understand that various modifications are possible within the limits without departing from the scope of the present invention with respect to the above-described embodiments. will be. Therefore, the scope of the present invention should not be limited to the described embodiments and should be defined by all changes or modifications derived from the claims and equivalent concepts as well as the claims to be described later.

1: wheelchair
8: Stairs
9: sidewalk block
10: wheelchair frame
11: frame
13: seating area
15: drive wheel
3: Electric assist module
30: caterpillar part
31: wheel
33: chain belt
35: belt support
351: sensor home
40: wheelchair angle adjustment unit
41: tilting frame
43: tilting module
50, 500: landing gear part
51, 510: gear shaft
53: front landing wheel
55: rear landing wheel
530: omni wheel
531: auxiliary wheel
57: drive module
70: control unit
80: pressure sensing unit
81: first pressure sensor
83: second pressure sensor
801: elastic member
803: pressure sensor

Claims (7)

In the electric assist module which is provided with a seating part on which a passenger sits on a frame having a footrest and a handle, and is detachable from a wheelchair frame provided with driving wheels on both sides of the frame,
A caterpillar part provided with a plurality of wheels and a chain belt for rotating the wheels, the caterpillar part being mounted on the wheelchair frame to raise and lower stairs or steps of the wheelchair frame;
a landing gear unit provided in the caterpillar unit, the free ends of which are raised/lowered before/after the center of gravity of the wheelchair frame as an axis; and
It includes a pressure sensing unit provided on the lower surface of the caterpillar unit,
The pressure sensing unit detects the pressure change of the caterpillar unit, the electric assist module, characterized in that for determining the last section of the step (stair-level entry section).
The method of claim 1,
The pressure sensing unit,
a first pressure sensor provided at a front position of the caterpillar part;
Electric assist module comprising a second pressure sensor provided at a rear position of the caterpillar part.
The method of claim 1,
The caterpillar part,
A sensor groove for accommodating the pressure sensor is formed on the lower surface,
An elastic member for imparting elasticity in the height direction and a plurality of pressure sensors for sensing the pressure of the elastic member are accommodated in the sensor groove.
The method of claim 1,
Electric assist module, characterized in that it further comprises a control unit for determining whether to enter the flat ground of the caterpillar unit by using the measured pressure data of the pressure sensing unit.
5. The method of claim 4,
The control unit is
After the pressure is sensed in the rear of the caterpillar unit through the pressure sensing unit, when pressure is sensed in the front, it is determined that the caterpillar unit is in a state of running stairs,
After the pressure is sensed in the front and rear of the caterpillar part, if the pressure is not detected in the front, it is determined that the stair has entered a flat section and the landing gear part is lowered.
The method of claim 1,
It is fastened to the wheelchair frame in the area behind the caterpillar part,
The electric assist module, characterized in that the wheelchair angle adjustment unit for maintaining the seating portion horizontally by tilting the wheelchair frame when the caterpillar unit ascends/decreases the stairs.
7. The method of claim 6,
The wheelchair angle adjustment unit,
a tilting frame having one end detachably coupled to a frame forming a backrest of the wheelchair frame, and the other end being detachably coupled to a seat portion or a lower frame of the seat portion of the wheelchair frame; and
Electric assist module comprising a tilting module having a well-known power means capable of pivoting or rotating the tilting frame at a predetermined angle based on the caterpillar part.

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