CN102697610B - Double-crawler-wheel obstacle crossing wheelchair - Google Patents

Abstract

An obstacle-crossing wheelchair with double track wheels, comprising: a chair part; a switching mechanism, used for switching between the roller transmission and the transmission of track wheels of the obstacle-crossing wheelchair with double track wheels, and the transmission of the track wheels is connected by a connecting bracket. The first track wheel and the second track wheel, the maximum angular velocity of the track wheel is In the formula, ω is the angular velocity, m is the mass of the multifunctional stair climbing wheelchair, h is the height of the center of gravity of the multifunctional stair climbing wheelchair, L is the contact length between the track wheel and the ground, J is the moment of inertia of the multifunctional stair climbing wheelchair, and α is the track The angle between the bottom line of the wheel and the ground, r is the angle between the line connecting the center of gravity of the multifunctional stair climbing wheelchair and the front ground point and the track wheel. The switching mechanism of the double-track wheel obstacle-crossing wheelchair of the present invention uses the five-bar mechanism to compensate the structural error of the four-bar mechanism, realizes high-precision motion output or completes more complex motion rules, and adopts the dual-track way to overcome obstacles to ensure obstacle surmounting the stability.

Description

Double track wheel obstacle wheelchair

technical field

The invention relates to the technical field of machinery and control, in particular to an obstacle-surmounting wheelchair with double crawler wheels.

Background technique

Wheelchairs are an indispensable means of transportation for the elderly and infirm. But, traditional wheelchair just can't cross when encountering hurdle. Among them, going up and down stairs is the biggest obstacle for these people with disabilities. In 200, the country considered installing elevators for these houses in order to solve the problem of going up and down stairs in these houses, but due to various reasons, the plan was shelved.

At present, the way abroad to solve the problem of wheelchair users crossing the stairs is to use the emergency evacuation transport equipment of the building - the stair climber, which is about to temporarily fix the wheelchair on the stair climber, so as to go up and down the stairs. Put it back to the original place after use, and the operation procedure is loaded down with trivial details. Although it can solve the problem of going up and down stairs for wheelchair users, it cannot go up and down stairs in buildings that are not equipped with stair climbing vehicles.

Stair climbing wheelchairs at home and abroad usually use a four-bar mechanism or a planetary gear mechanism to realize going up and down stairs. For the planetary wheel type stair-climbing wheelchair, the structure is simple, and a self-locking mechanism is used to ensure that it does not fall when going up and down stairs. But this stair-climbing wheelchair has poor adaptability to stairs, and cannot meet the needs of users for comfort and reliability.

For the stair-climbing wheelchair with extra track wheels, the way of extra track wheels is adopted when going up and down stairs, which ensures the continuity of the process of going up and down stairs. However, the crawler wheel type stair-climbing wheelchair with additional track wheels needs to be completed with the help of others every time the track wheels are installed, and the operation is cumbersome, the structure is heavy, and it is inconvenient to carry, which greatly limits the places where the wheelchair can go up and down stairs.

For the crawler wheel and wheel combination stair climbing wheelchair, the wheelchair uses a four-bar structure to realize the conversion of the wheel and the track wheel by lifting the wheel. However, the stair-climbing wheelchair adopts a four-bar structure and has only one degree of freedom, so it cannot realize high-precision operation output or complete more complicated motion laws.

Therefore for the problems existing in the prior art, the designer of this case relies on the experience of being engaged in this industry for many years, actively researches and improves, so there is invention a kind of double crawler wheel obstacle-surmounting wheelchair.

Contents of the invention

The present invention is aimed at the conventional stair-climbing wheelchairs in the prior art, which have poor adaptability to stairs, cannot meet the needs of users for comfort and reliability, and cannot achieve high-precision operation output or complete more complex movements. The utility model provides an obstacle-surmounting wheelchair with double crawler wheels to overcome defects such as regularity.

In order to solve the above-mentioned problems, the present invention provides a double track wheel obstacle-surmounting wheelchair, comprising: a chair part, the chair part is used for the user to sit on; a switching mechanism, the switching mechanism is arranged under the chair part, and is used to The switch between the roller transmission and the track wheel transmission of the double track wheel obstacle-crossing wheelchair, the track wheel transmission has a first track wheel and a second track wheel connected by a connecting bracket, the first track wheel and the second track wheel The two track wheels further include a bracket; a support wheel, the support wheel is arranged on the support; a first gear, a second gear, and a third gear that are arranged on one side of the support wheel and mesh with each other; a fourth gear integrally formed with the second gear and intermeshed with each other; a fifth gear integrally formed with the third gear and intermeshed with each other, and external teeth of the fourth gear and the fifth gear intermeshed and positioned at The track gear on the outside of the support wheel, the maximum angular velocity of the track wheel is In the formula, ω is the angular velocity, m is the mass of the multifunctional stair climbing wheelchair, h is the height of the center of gravity of the multifunctional stair climbing wheelchair, L is the contact length between the track wheel and the ground, J is the moment of inertia of the multifunctional stair climbing wheelchair, and α is the track The angle between the bottom line of the wheel and the ground, r is the angle between the line connecting the center of gravity of the multifunctional stair climbing wheelchair and the front ground point and the track wheel.

Optionally, one end of the switching mechanism is movably connected to the first fixed point provided on the double-track wheel obstacle-crossing wheelchair, and the other end of the switching mechanism is connected to the second fixed point on the double-track-wheel obstacle-crossing wheelchair. Fixed point fixed connection.

Optionally, one end of the first rod of the switching mechanism is movably connected with the first fixed point; the other end of the first rod is movably connected with one end of the second rod of the switching mechanism; the switching mechanism The other end of the second rod is flexibly connected to one end of the first linear motor on the fourth rod; the first bending part of the second rod is axially connected at the end point of the third rod; The other end of the four rods is movably connected with the fifth rod; the other end of the fifth rod is fixedly connected with the third rod; one end of the sixth rod is fixedly arranged on the third rod; The other end of the sixth rod is flexibly connected to one end of the second linear motor on the seventh rod; the other end of the seventh rod is flexibly connected to one end of the eighth rod; the other end of the eighth rod It is movably connected with one end of the rod fixed at the second fixed point; the second bending part of the eighth rod is axially connected at the end point of the third rod.

Optionally, the switching mechanism of the double track wheel obstacle surmounting wheelchair includes the following steps in the switching process:

Executing step S1: the first linear motor is driven and extended laterally;

Execute step S2: the end of the second rod that is movably connected to the first linear motor is moved clockwise with the first fixed point as the center of the circle, and the length between the two points is the radius; that is, the first One rod rotates clockwise around point A, the second rod is driven by the first linear motor, rotates with the first rod, and pushes the end point C of the third rod to move up and down;

Executing step S3: the eighth rod is driven by the second DC motor to rotate around the end of the rod that is different from the second fixed point, and the end point of the third rod is pushed by the eighth rod to The J point moves up and down.

Executing step S4: during the up-and-down movement of the end points C and J of the third rod, the crawler wheels are lifted up and down, and then the switch between the roller transmission and the track wheel transmission is realized.

In summary, the switching mechanism of the double-track wheel obstacle-climbing wheelchair of the present invention uses a five-bar mechanism to compensate for the structural error of the four-bar mechanism, so as to realize high-precision motion output or complete more complex motion laws, and adopts a double-track method to overcome obstacles. Obstacles to ensure the stability of overcoming obstacles.

Description of drawings

Fig. 1 shows the schematic diagram of the three-dimensional structure of the obstacle-crossing wheelchair with double track wheels of the present invention;

Fig. 2 shows the schematic structural diagram of the principle structure of the switching mechanism of the double-track wheel obstacle-climbing wheelchair of the present invention;

Fig. 3 shows the schematic diagram of the movement process of the switching mechanism of the double track wheel obstacle-crossing wheelchair of the present invention;

Fig. 4 shows the initial schematic diagram of the movement process of the switching mechanism of the double track wheel obstacle-climbing wheelchair of the present invention;

Fig. 5 is a schematic diagram during the movement of the switching mechanism of the double track wheel obstacle-climbing wheelchair of the present invention;

Fig. 6 is a schematic diagram of the track wheel structure of the double track wheel obstacle-climbing wheelchair of the present invention;

Fig. 7 is a schematic diagram showing that the double-track wheel obstacle-climbing wheelchair of the present invention prepares to climb over an obstacle;

Fig. 8 is a schematic diagram of the process of overcoming obstacles of the double-track wheel obstacle-surmounting wheelchair according to the present invention;

Fig. 9 is a schematic diagram showing that the double-track wheel obstacle-climbing wheelchair of the present invention is about to complete overcoming an obstacle.

Detailed ways

In order to illustrate the technical content, structural features, achieved goals and effects of the present invention in detail, the following will be described in detail in conjunction with the embodiments and accompanying drawings.

Please refer to FIG. 1 . FIG. 1 is a three-dimensional structural schematic view of the double track wheel obstacle-surmounting wheelchair of the present invention. The double-track wheel obstacle-crossing wheelchair 1 includes a chair part 10, which is used for the user to sit on; a switching mechanism 11 between the roller transmission and the track wheel transmission, and the switching mechanism 11 is arranged on the chair part 10, and is used for switching between the roller transmission and the track wheel transmission of the standing aid climbing mechanism 1, and the auxiliary standing mechanism 12, the auxiliary standing mechanism 12 is arranged on the lower side of the chair part 10, and is used for Assists the user in standing.

Please continue to refer to Fig. 1, and refer to Fig. 2, Fig. 3, Fig. 4, and Fig. 5 in combination. Fig. 2 shows a schematic structural diagram of the principle structure of the switching mechanism of the double-track wheel obstacle-surmounting wheelchair of the present invention. Fig. 3 is a schematic diagram showing the principle structure of the movement process of the switching mechanism of the double-track wheel obstacle-climbing wheelchair of the present invention. Fig. 4 is a schematic diagram showing the initial movement process of the switching mechanism of the double-track wheel obstacle-climbing wheelchair of the present invention. Fig. 5 is a schematic diagram showing the movement process of the switching mechanism of the double-track wheel obstacle-climbing wheelchair of the present invention. In the present invention, the double-track wheel obstacle-climbing wheelchair 1 adopts a double-track-wheel transmission mode when going up and down stairs and over obstacles. Wherein, the switching between the roller transmission mode and the track wheel transmission mode is realized by the lifting control of the track wheel by the switching mechanism 11 . One end of the switching mechanism 11 is movably connected with the first fixed point 13 provided on the double-track wheel obstacle-crossing wheelchair 1; Two fixed points 14 are fixedly connected.

Please continue to refer to Fig. 2, Fig. 3, Fig. 4, and Fig. 5. The switching mechanism 11 of the double-track wheel obstacle-climbing wheelchair 1 of the present invention is a five-bar mechanism, controlled by two linear motors, with 8 movable mechanisms and 11 Low vice, which has 2 degrees of freedom. Specifically, point A at one end of the first rod 110 of the switching mechanism 11 is flexibly connected to the first fixed point 13; point B at the other end of the first rod 110 is connected to the second rod 111 of the switching mechanism 11 One end of the second rod 111 of the switching mechanism 11 is flexibly connected to point D at the other end of the second rod 111 and one end of the first linear motor 113a on the fourth rod 112 is flexibly connected; the first bending part of the second rod 111 1111 is axially connected at point C at the end point of the third rod 114; the other end E point of the fourth rod 112 is flexibly connected with the fifth rod 115; the other end of the fifth rod 115 is connected with the The third bar 114 is fixedly connected; one end of the sixth bar 116 is fixedly arranged on the third bar 114; the other end of the sixth bar 116 is connected with the second linear motor 113b on the seventh bar 117 One end is movably connected; the other end of the seventh rod 117 is movably connected with one end of the eighth rod 118; the other end of the eighth rod 118 is movably connected with one end of the rod 119 fixedly arranged on the second fixed point 14 ; The second bending portion 1181 of the eighth rod 118 is axially connected at the end point J of the third rod 114 .

Please continue to refer to FIG. 2 , FIG. 3 , FIG. 4 , and FIG. 5 , and describe in detail the working principle of the switching mechanism 11 of the double-track wheel obstacle-climbing wheelchair 1 of the present invention. When the switching mechanism 11 of the double-track wheel obstacle-climbing wheelchair 1 of the present invention switches between the roller drive and the track wheel drive, the following steps are included:

Step S11 is executed: the first linear motor 113a is driven and extended laterally. At this time, the point B at one end of the second rod 111 that is movably connected with the first linear motor 113a is different from the connection point. The point A of the first fixed point 13 is the center of the circle, and the length of AB is the radius and moves clockwise. ; That is, the first rod 110 rotates clockwise around point A. Under the push of the first linear motor 113a, the second rod 111 rotates with the first rod 111 and pushes the end point C of the third rod 114 to move up and down.

Executing step S12: the eighth rod 118 is driven by the second DC motor 113b to rotate around the point K at one end of the rod 119 that is different from the second fixed point 14, and under the push of the eighth rod 118, the The end point J of the third rod 114 moves up and down.

Step S13 is executed: during the up-and-down movement of the end points C and J of the third rod 114 , the lifting of the track wheels is realized, and then the switch between the roller transmission and the track wheel transmission is realized.

Please refer to FIG. 6 . FIG. 6 is a schematic diagram of the track wheel structure of the double track wheel obstacle-surmounting wheelchair of the present invention. The track wheels 18a, 18b of the double-track wheel obstacle-crossing wheelchair 1 all include a bracket 180; a support wheel 181, and the support wheel 181 is arranged on the bracket 180; The first gear 182, the second gear 183, and the third gear 184 that mesh with each other; the fourth gear 185 that is integral with the second gear 183 and meshes with each other; The fifth gear 186 , and the crawler gear 187 which is externally engaged with the fourth gear 185 and the fifth gear 186 and located outside the support wheel 181 . Wherein, the track wheel 18a is connected to the track wheel 18b through a connecting bracket 188 . During the movement of the track wheels 18a, 18b, the external motor (not shown) drives the first gear 181 between the second gear 183 and the third gear 184 to rotate; A gear 181 drives the second gear 183 and the third gear 184 to rotate; the second gear 183 and the third gear 184 further drives the fourth gear 185 and the fifth gear 186 to rotate, This drives the rotation of the track gear 187 .

Please continue to refer to FIG. 6 , and refer to FIG. 7 , FIG. 8 , and FIG. 9 in combination. FIG. 7 shows a schematic diagram of the obstacle-climbing wheelchair of the present invention when encountering obstacles and preparing to climb over. Fig. 8 is a schematic diagram of the process of the obstacle-climbing wheelchair with double track wheels according to the present invention. Fig. 9 is a schematic diagram showing that the double-track wheel obstacle-surmounting wheelchair of the present invention encounters an obstacle and is about to complete the overturning process.

When the double-track wheel obstacle-surmounting wheelchair 1 of the present invention encounters a protruding obstacle 2 and prepares to climb over, the track wheel 18b adjusts its state. For example, the double-track-wheel obstacle-surmounting wheelchair 1 climbs over the obstacle at a speed v Object 2, L is the contact length between the track wheel 18b and the ground, when the center of gravity is on the left side of the fulcrum O of the obstacle 2, the angle α between the bottom line of the track wheel 18b and the ground will gradually increase with time t big

$\mathrm{<span\; class="notranslate">\; sin</span>}\mathrm{<span\; class="notranslate">\; \&alpha;</span>}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; h</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}}{\mathrm{<span\; class="notranslate">\; L</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; vt</span>}}$

In the formula: h ₀ is the height of the obstacle 2, since h ₀ <<L, the value of α is small, sinα=α, at this time, the angular velocity ω and angular acceleration a of the obstacle-crossing wheelchair 1 with double track wheels are respectively

$\mathrm{<span\; class="notranslate">\; \&omega;</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; d\&alpha;</span>}}{\mathrm{<span\; class="notranslate">\; dt</span>}}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; vh</span>}}_{\mathrm{<span\; class="notranslate">\; o</span>}}}{{<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; vt</span>}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}$

$\mathrm{<span\; class="notranslate">\; a</span>}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; d\&alpha;</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}{\mathrm{<span\; class="notranslate">\; d</span>}{\mathrm{<span\; class="notranslate">\; t</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; v</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; h</span>}}_{\mathrm{<span\; class="notranslate">\; o</span>}}}{{<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; vt</span>}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 3</span>}}}$

When the double-track wheel obstacle-climbing wheelchair 1 of the present invention climbs over the obstacle 2, the functional stair-climbing wheelchair 1 continues to climb up the obstacle 2 at a speed v, and the center of gravity exceeds the fulcrum O. Under the action of gravity and movement speed , the functional stair climbing wheelchair 1 moves in a plane, and moves forward while rotating around the fulcrum O. At this time, the position of the center of gravity is gradually away from the fulcrum O of the obstacle 2, and the moment of the center of gravity to the fulcrum O gradually increases.

Let h be the height of the center of gravity of the functional stair climbing wheelchair 1, and _L1 be the distance from the center of gravity of the functional stair climbing wheelchair 1 to the front grounding point of the track wheel 18b. According to the dynamic differential equation, the variation law of the angular acceleration a of the functional stair climbing wheelchair 1 around the point with α can be obtained.

J×a=mg×cosα×(vt-L ₁ +h×tanα)

In the formula: J is the moment of inertia of the functional stair climbing wheelchair 1.

When the functional stair-climbing wheelchair 1 continues to move forward, the front end of the functional stair-climbing wheelchair 1 first touches the ground, and the functional stair-climbing wheelchair 1 has a greater inertia, so it hits the ground with a greater impact force. , resulting in a strong collision between the functional stair climbing wheelchair 1 and the ground. For example, assuming that the front landing point of the track wheel 18a is point A, its speed is U _A , and the speed after the collision is V _A , according to the impulse theorem, it can be established that the front ground point of the functional stair climbing wheelchair 1 collides with the ground The moment of inertia I of the impact.

${\mathrm{<span\; class="notranslate">\; I</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; m</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \&times;</span>{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}{<span\; class="notranslate">\; [</span>\frac{\mathrm{<span\; class="notranslate">\; I</span>}}{\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; \&times;</span>{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \&times;</span>\mathrm{<span\; class="notranslate">\; cos</span>}\mathrm{<span\; class="notranslate">\; \&alpha;</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 0.5</span>}<span\; class="notranslate">\; \&times;</span>\mathrm{<span\; class="notranslate">\; L</span>}}<span\; class="notranslate">\; ]</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; j</span>}{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}$

When the functional stair climbing wheelchair 1 collides with the ground, due to acceleration and inertia, the functional stair climbing wheelchair 1 suddenly turns from rotating around the fulcrum O to turning around the front ground point A, thereby generating an additional inertial angle c.

For example, assuming that the functional stair climbing wheelchair 1 climbs down an obstacle 2 with an inclination angle of g, it is known that the height of the center of gravity of the functional stair climbing wheelchair 1 is h, and the connection between the center of gravity k and the front grounding point A is The angle between line kA and track wheel 18a is r angle. According to the energy conservation principle, the relationship between the additional inertial angle c and the angular velocity at the time of collision can be established:

$\mathrm{<span\; class="notranslate">\; c</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; arcsin</span>}<span\; class="notranslate">\; [</span>\frac{\mathrm{<span\; class="notranslate">\; J</span>}<span\; class="notranslate">\; \&times;</span>{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}{\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; mg</span>}\sqrt{{\mathrm{<span\; class="notranslate">\; h</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; L</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; sin</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; \&alpha;</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; r</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ]</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; \&alpha;</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; r</span>}<span\; class="notranslate">\; )</span>$

From the analysis, it can be known that when the functional stair climbing wheelchair 1 descends the stairs, every step down is equivalent to the functional stair climbing wheelchair 1 crossing an obstacle, and an additional inertial angle is generated at the same time. When a+c+r<90°, the functional stair climbing wheelchair 1 tilts forward and then falls back to the obstacle 2 due to gravity, causing the obstacle 2 to vibrate and impact the functional stair climbing wheelchair 1 . That is, when the functional stair climbing wheelchair 1 steps over the next step, two impacts occur. When a+c+r>90°, the center of gravity exceeds the critical state, and the functional stair climbing wheelchair 1 will turn forward around the front ground point A and roll down the stairs. Obviously, to prevent the functional stair climbing wheelchair 1 from rolling down the stairs, it is necessary to control the movement speed of the functional stair climbing wheelchair 1 . Obviously, the greater the angular velocity of the functional stair climbing wheelchair 1, the greater the inertial angle. When the function stair climbing wheelchair 1 was in a critical state, its maximum angular velocity was In the formula, ω is the angular velocity, m is the mass of the obstacle-crossing wheelchair with double track wheels, h is the height of the center of gravity of the obstacle-crossing wheelchair with double-track wheels, L is the contact length between the track wheels and the ground, and J is the moment of inertia of the obstacle-crossing wheelchair with double-track wheels, α is the angle between the bottom line of the track wheels and the ground, and r is the angle between the line connecting the center of gravity of the obstacle-climbing wheelchair with double track wheels and the front ground point and the track wheels.

In summary, the switching mechanism of the double-track wheel obstacle-climbing wheelchair of the present invention uses a five-bar mechanism to compensate for the structural error of the four-bar mechanism, so as to realize high-precision motion output or complete more complex motion laws, and adopts a double-track method to overcome obstacles. Obstacles to ensure the stability of overcoming obstacles.

Those skilled in the art will appreciate that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. Therefore, if any modification or variation falls within the scope of protection of the appended claims and their equivalents, the present invention is deemed to cover such modification and variation.

Claims (4)

1. A double-track wheel obstacle-surmounting wheelchair, characterized in that, the double-track-wheel obstacle-surmounting wheelchair comprises: a chair portion for a user to sit on; A switch mechanism, the switch mechanism is arranged under the chair part, and is used for switching between the roller transmission and the track wheel transmission of the double track wheel obstacle-crossing wheelchair, and the track wheel transmission has a first connected by a connecting bracket. The track wheel and the second track wheel, the first track wheel and the second track wheel further include a bracket; a support wheel, the support wheel is set on the support; set on one side of the support wheel, and two two intermeshing first gears, second gears, and third gears; a fourth gear integrally formed with said second gears and intermeshed with each other; a fifth gear integrally formed with said third gears and intermeshed with each other, and For the crawler gear that meshes with the external teeth of the fourth gear and the fifth gear and is located outside the support wheel, the maximum angular velocity of the first crawler wheel is In the formula, ω is the angular velocity, m is the mass of the obstacle-climbing wheelchair with double track wheels, h is the height of the center of gravity of the obstacle-climbing wheelchair with double-track wheels, L is the contact length between the track wheels and the ground, and J is the moment of inertia of the obstacle-climbing wheelchair with double-track wheels, α is the angle between the bottom line of the track wheels and the ground, and r is the angle between the line connecting the center of gravity of the obstacle-climbing wheelchair with double track wheels and the front ground point and the track wheels. 2. The double-track wheel obstacle-surmounting wheelchair according to claim 1, wherein one end of the switching mechanism is movably connected to a first fixed point provided on the double-track-wheel obstacle-breaking wheelchair, and the switching mechanism The other end is fixedly connected with the second fixed point on the double-track wheel obstacle-surmounting wheelchair. 3. The double-track wheel obstacle-surmounting wheelchair as claimed in claim 1, wherein one end of the first rod of the switching mechanism is movably connected to a first fixed point; the other end of the first rod is connected to the One end of the second rod of the switching mechanism is flexibly connected; the other end of the second rod of the switching mechanism is flexibly connected to one end of the first linear motor on the fourth rod of the switching mechanism; the first bending part of the second rod The end point of the third rod of the switching mechanism is axially connected; the other end of the fourth rod is movably connected with the fifth rod of the switching mechanism; the other end of the fifth rod is fixedly connected with the third rod; switching One end of the sixth rod of the mechanism is fixedly arranged on the third rod; the other end of the sixth rod is movably connected with one end of the second linear motor on the seventh rod of the switching mechanism; the other end of the seventh rod One end is movably connected with one end of the eighth rod of the switching mechanism; the other end of the eighth rod is movably connected with one end of the rod fixed at the second fixed point; the second bending part of the eighth rod is in the The end point shaft connection of the third rod. 4. The double-track wheel obstacle-surmounting wheelchair according to claim 3, wherein the switching mechanism of the double-track-wheel obstacle-surmounting wheelchair comprises the following steps during the switching process: Executing step S1: the first linear motor is driven and extended laterally; Execute step S2: the end of the second rod that is movably connected to the first linear motor is moved clockwise with the first fixed point as the center of the circle, and the length between the two points is the radius; that is, the first One rod rotates clockwise around point A, the second rod is driven by the first linear motor, rotates with the first rod, and pushes the end point C of the third rod to move up and down; Executing step S3: the eighth rod is driven by the second DC motor to rotate around the end of the rod that is different from the second fixed point, and the end point of the third rod is pushed by the eighth rod to J point moves up and down; Executing step S4: during the up-and-down movement of the end points C and J of the third rod, the crawler wheels are lifted up and down, and then the switch between the roller transmission and the track wheel transmission is realized.