TWI550428B - Multi-legged stair-climbingmechanism and design method therefor - Google Patents

Description

Multi-legged ladder mechanism and design method thereof

The invention relates to a multi-legged ladder mechanism and a design method thereof, in particular to a method for designing a multi-leg ladder mechanism by changing the size ratio configuration of the eight-link of the Jansen mechanism by simulating the trajectory of the human body ladder and the mechanism .

Traditional ladder mechanisms are mostly wheeled or tracked. Wheel type ladder mechanism, for example, Republic of China invention patent No. I462717 "Household stair dust removal robot", Republic of China invention patent No. I462718 "ladder robot", etc.; crawler type ladder mechanism such as Republic of China invention patent No. I468155 "Electric wheelchair", China Republic of China invention patent No. I417212 "Electric ladder truck device".

However, neither the wheel type ladder mechanism nor the crawler type ladder mechanism can simulate the trajectory of the human ladder and perform the ladder movement.

See "T. Jansen, The Great Pretender, 010 Publishers, 2007.", Jansen has designed a multi-legged motion mechanism. As shown in the eighth figure, each leg of the mechanism is composed of an eight-bar linkage (I), wherein the eight-link (I) includes a plurality of pivot points and a contact point (II), one of which The pivot point is the transmission point (III), and one of the pivot points is a fixed point (IV) that does not generate displacement. The multi-legged motion mechanism generally drives the transmission point (III) by a crank mechanism and thereby drives the eight-link (I) mechanism.

However, Jansen's multi-footed motion mechanism can only move in the plane and cannot climb the ladder.

Based on the eight-link of the multi-foot motion mechanism of Jansen, the present invention proposes a multi-leg ladder mechanism design method comprising the following steps:

A. Measuring the movement trajectory of the foot when the human body climbs the ladder; B. Using the optimization calculation method, the movement trajectory of a contact point for contacting the ground in the Jansen eight-link is approached to the ankle of the human foot The trajectory of the movement, according to which the size ratio of each link in the Jansen eight-link is adjusted.

Further, the closed loop equation is used to calculate the motion trajectory of the contact point in the Jansen eight-link; in step A, the position vector of the upper body corresponding to the upper body of the human body is calculated, and the motion trajectory of the foot is obtained; The motion trajectory of the contact point is used to reduce the motion trajectory of the human foot and minimize it, so that the motion trajectory of the contact point approaches the motion trajectory of the human foot.

Further, including step C, the Jansen eight-links after the plurality of adjustments are arranged in pairs are arranged in pairs, and the paired Jansen eight-links are arranged one behind the other and have the same moving direction, but the phase difference is 180 degrees.

The invention further proposes a multi-legged ladder mechanism manufactured by using the foregoing multi-leg ladder mechanism design method, comprising:

a pedestal; a plurality of crank drive mechanisms disposed on the base; the plurality of adjusted Janes eight-links respectively corresponding to one of the crank drive mechanisms, one of each of the Jansen eight-link pivot joints a transmission point and a fixed point that does not generate a displacement, the transmission point is connected to the crank drive mechanism, the fixed point is pivotally connected to the base; the plurality of Jansen eight links are arranged in pairs, and the pairs are arranged in Jansen The eight links move in the same direction but have a phase difference of 180 degrees.

Further, the pair of arranged Jansen eight-link crank drive mechanisms are connected by a linkage mechanism. Further, the crank drive mechanism is an eccentric transmission gear, and the linkage mechanism is a plurality of connected gears.

Further, there are four pairs of arranged Jansen eight-links arranged side by side on the base, adjacent to the pair of Jansen eight-links, one side of the Jansen eight-link and the other side of the Jansen eight-link The phases of the rods are the same.

Further, a power unit is coupled to the crank drive mechanism. Wherein, the power unit comprises two cranks respectively connected to two of the Jansen eight-links arranged in pairs.

Through the above technical features, the following effects can be produced:

1. By optimizing the design method, changing the size ratio of the Jansen eight-link, so that the movement track of the Jansen eight-bar linkage conforms to the movement trajectory of the ladder at the foot of the human foot, so the multi-legged ladder mechanism of the present invention can be stabilized The upper and lower steps.

2. The climbing action of the ladder mechanism of the present invention simulates the trajectory of the ladder at the ankle of the human foot, and can be applied to the use of the action aid or the bionic robot in the future.

In combination with the above technical features, the main effects of the multi-legged ladder mechanism and its design method of the present invention will be clearly shown in the following embodiments.

The method for designing a multi-legged ladder mechanism of the present invention comprises the following steps:

Referring to the first and second figures, the closed loop equation is used to calculate the trajectory of the contact point of a Jansen eight-link to contact the ground. The contact point, each pivot point, a driving point, and the length and angle relationship of each link are as shown in the figure.

Obtained by the closed loop equation:

(1)

(2)

Where R _j is the vector of the link, r _j is the length of the link, and θ _j is the angle of the link.

Bring equation (2) into equation (1):

(3)

(4)

Where θ ₁ =0, so equations (3) and (4) become:

(5)

(6)

Combine equations (5) and (6):

(7)

Simplify equation (7):

(8)

among them,

; (9)

Further simplify equation (8):

(10)

among them,

b=-2 (11) e=

Therefore, θ _{4 is} expressed as follows:

(12)

Bringing the formula (12) into the formula (3) and the formula (4), θ ₃ can be expressed as follows:

(13)

among them,

(14) c

as well as,

; (15)

Similarly, θ ₅ and θ ₆ can be expressed as follows:

(16)

(17)

among them,

(18)

as well as,

; ; (19)

As shown in the first figure, points C and D can be expressed as:

(20)

(twenty one)

Where O ₄ =[0,0] ^T , θ ₇ =θ ₄ -α

Let r _DC = ||CD|| , φ ₁ and φ ₂ be expressed as:

(twenty two)

(twenty three)

The first picture shows:

(twenty four)

(25)

among them,

(26)

Therefore, the position vector of the contact point of the Jansen eight-link can be expressed as:

(27)

Referring to the third A diagram, the third B diagram, the fourth diagram, and the fifth diagram, after obtaining the position vector of the contact point of the Jansen eight-link, the following steps are performed:

A. Measuring the movement trajectory of the foot when the human body climbs the ladder, wherein calculating the position vector of the foot corresponding to the upper body of the human body can obtain the motion trajectory of the foot. During the experiment, a light spot is set on the waist and ankle of the human body, and the track of the human body ladder is tracked by the light spot. In the third B picture, the N point is the waist spot position, and the M point is the foot spot position, so the human foot The motion track can be expressed as:

(28)

Equation (28) can be rewritten as:

(29)

Where i is the measured track point, this experiment takes 24 points as an example.

B. Using the optimization method, the trajectory of the contact point of the Jansen eight-link is approached to the trajectory of the human foot, and the size ratio of each link in the Jansen eight-link is adjusted accordingly. The method of optimization uses the trajectory of the contact point to deduct the motion trajectory of the human foot and minimize it, so that the trajectory of the contact point approaches the trajectory of the human foot. The optimization formula is as follows :

(30) =

According to the weighted sum method, the variables of the above optimization formula are r ₄ , r ₅ , r ₇ , r ₉ and r ₁₀ :

(31)

among them,

(32)

C. After optimization, the trajectory of the contact point of the Jansen eight-link is driven close to the trajectory of the human ladder, and the Jansen eight-link is adjusted in pairs and arranged in pairs, and arranged in pairs. The Jansen eight-bar linkage has the same direction of motion and a phase difference of 180 degrees, which simulates the human body ladder trajectory.

Referring to the sixth figure, the embodiment further cites one of the multi-legged ladder mechanisms manufactured by the above method, including:

a base (1); a plurality of crank drive mechanisms (2) disposed on the base (1); the plurality of adjusted Janes eight links (3) corresponding to one of the crank drive mechanisms (2) Each of the pivotal points of the Jansen eight-bar linkage (3) has a transmission point (31) and a fixed point (32) that does not generate a displacement, and the transmission point (31) is connected to the crank drive mechanism (2). The fixed point (32) is pivotally connected to the base (1); the plurality of Jansen eight links (3) are arranged in pairs, and the Jansen eight links (3) arranged in pairs are in the same direction and phase 180 degrees difference. In this embodiment, the pair of Jansen eight-links (3) are arranged in a front-to-back manner, and the crank drive mechanism (2) of the pair of arranged Jansen eight-links (3) is connected by a linkage mechanism (4), such as the foregoing The crank drive mechanism (2) is an eccentric drive gear, and the linkage mechanism (4) is a plurality of connected gears, and the crank drive mechanism (2) is connected by a power unit, wherein the power unit includes two motors (5) A crank drive mechanism (2) of two of the Jansen eight-bar linkages (3) arranged in pairs is respectively connected, and a controller (6) is disposed on the base (1) for controlling the operation of the motor (5). In this embodiment, the Jansen eight links (3) arranged in four pairs are arranged side by side on the base (1), adjacent to the pair of Jansen eight links (3), one side of which is Jansen eight The connecting rod (3) has the same phase as the Jansen eight-link (3) at the rear of the other side.

Referring to Figures 7A through 7D, in the actual test, the above mechanism can be stably used for the upper and lower steps.

In view of the foregoing description of the embodiments, the operation and the use of the present invention and the effects of the present invention are fully understood, but the above described embodiments are merely preferred embodiments of the present invention, and the invention may not be limited thereto. Included within the scope of the present invention are the scope of the present invention.

(1) ‧ ‧ pedestal
(2) ‧‧‧Crank drive mechanism
(3)‧‧‧Jansen eight-link
(31)‧‧‧ Transmission points
(32) ‧ ‧ fixed points
(4) ‧‧‧ linkage agencies
(5) ‧ ‧ motor
(6) ‧ ‧ controller

[First figure] is a schematic diagram of the Jansen eight-link. [Second picture] is a closed circuit diagram of the Jansen eight-link analysis using closed loop analysis. [Picture A] is a schematic diagram of measuring the movement of the human foot by mounting a light spot on the waist and ankle of the human body (1). [Third B] is a schematic diagram of measuring the trajectory of the human foot by installing a light spot on the waist and ankle of the human body (2). [Fourth figure] is a schematic diagram of the movement trajectory of the human foot. [Picture 5] is a schematic diagram of the motion trajectory of the contact point of the Jansen eight-link after optimization. [Sixth figure] is an external structural diagram of the multi-legged ladder mechanism of the present invention. [Seventh A] is a schematic diagram (1) of a multi-legged ladder mechanism for climbing a ladder in the embodiment of the present invention. [Fig. 7B] is a schematic view (2) of a multi-legged ladder mechanism used for climbing a ladder in the embodiment of the present invention. [Seventh C] is a schematic diagram (3) of a multi-legged ladder mechanism for climbing a ladder in the embodiment of the present invention. [Seventh D] is a schematic diagram (four) of a multi-legged ladder mechanism used for climbing a ladder in the embodiment of the present invention. [Eighth image] is a schematic diagram of each action point in the conventional Jansen eight-link.

(1) ‧ ‧ pedestal

(2) ‧‧‧Crank drive mechanism

(3)‧‧‧Jansen eight-link

(31)‧‧‧ Transmission points

(32) ‧ ‧ fixed points

(4) ‧‧‧ linkage agencies

(5) ‧ ‧ motor

(6) ‧ ‧ controller

Claims (10)

A multi-leg ladder mechanism design method includes the following steps: A. measuring the movement track of the foot when the human body climbs the ladder; B. using an optimization operation method to make a contact point of the Jansen eight-link to contact the ground The trajectory of the movement approaches the trajectory of the human foot, and the size ratio of each of the links in the Jansen eight-link is adjusted accordingly. For example, in the design method of the multi-legged ladder mechanism described in claim 1, the closed circuit equation is used to calculate the Jansen eight-link, which corresponds to one of the other pivot joints of the Jansen eight-link and the crank drive mechanism. Driving the position vector of the point to obtain the motion trajectory of the contact point; in step A, calculating the position vector of the foot corresponding to the upper body of the human body, the motion trajectory of the foot can be obtained; in step B, using the contact point The motion track deducts and minimizes the motion trajectory of the human foot, so that the motion trajectory of the contact point approaches the motion trajectory of the human foot. The method for designing a multi-legged ladder mechanism as described in claim 1 further includes the step C of arranging the plurality of the Jansen eight-links after being adjusted in pairs, arranged in pairs in pairs, and arranged in pairs in the Jansen eight company The rods move in the same direction but with a phase difference of 180 degrees. A multi-legged ladder mechanism manufactured by using the multi-leg ladder mechanism design method described in claim 1 of the patent application, comprising: a base; a plurality of crank drive mechanisms disposed on the base; and a plurality of adjustment ratios The Jansen eight-links respectively correspond to one of the crank drive mechanisms, and one of the pivot points of each Jansen eight-link has a transmission point and a fixed point that does not generate a displacement, and the transmission point is connected to the crank drive mechanism, the fixing The point is pivotally connected to the base; the plurality of Jansen eight links are arranged in pairs, and the Jansen eight-bar linkages arranged in pairs are in the same direction but with a phase difference of 180 degrees. For example, the multi-legged ladder mechanism described in claim 4, wherein the paired Jansen eight-links are arranged in a front-to-back manner. For example, in the multi-leg ladder mechanism described in claim 5, the eccentric drive mechanism of the pair of arranged Jansen eight-links is connected by a linkage mechanism. The multi-legged ladder mechanism according to claim 6, wherein the crank drive mechanism is an eccentric transmission gear, and the linkage mechanism is a plurality of connected gears. For example, in the multi-leg ladder mechanism described in claim 6, further, there are four pairs of arranged Jansen eight-links arranged side by side on the base, adjacent to the pair of Jansen eight-links, one of which The front Janes eight-link is the same phase as the Jansen eight-link on the other side. For example, in the multi-leg ladder mechanism described in claim 8, further, a power unit is coupled to the crank drive mechanism. The multi-legged ladder mechanism of claim 9, wherein the power unit comprises two motors respectively connected to two of the Jansen eight-link crank drive mechanisms arranged in pairs.