1. The mechanical leg of the double four-bar linkage mechanism is characterized by mainly comprising a side swing assembly (4), a thigh four-bar linkage assembly (1), a shank four-bar linkage assembly (2) and a sole (3);

a motor output shaft (110) of the thigh driving unit (11) is fixedly connected with a front rotary pair (121) of a thigh driving shaft connecting rod (12), a rear rotary pair (122) of the thigh driving shaft connecting rod (12) is hinged with a front rotary pair (141) of a thigh (14) through a thigh connecting rod (13), a rotating shaft (140) of the thigh (14) is connected with a thigh supporting shaft (16) through a rolling shaft (15), and the thigh supporting shaft (16) is fixedly connected on a support (101);

a motor output shaft (210) of a lower leg driving unit (21) of the lower leg four-link assembly (2) is fixedly connected with a front rotating pair (221) of the lower leg driving shaft connecting rod (22), a rear rotating pair (222) of the lower leg driving shaft connecting rod (22) is hinged with a front rotating pair (241) of the lower leg (24) through a lower leg connecting rod (23), a rotating shaft (240) of the lower leg (24) is hinged on a rear rotating pair (142) of the thigh (14), and a sole (3) is fixedly connected on a rear rotating pair (242) of the lower leg (24);

the rotating shaft (140) of the thigh (14) and the front rotary pair (221) of the shank driving shaft connecting rod (22) are coaxial with the roller (15), and the roller (15) and the motor output shaft (210) of the shank driving unit (21) are coaxial;

the side swing component (4) is fixedly connected to the support (101).

2. The mechanical leg of a double four-bar linkage according to claim 1, characterized in that: the lower leg driving unit (21) and the thigh driving unit (11) are sequentially arranged in parallel up and down and are arranged in the support (101), the support (101) is fixedly connected with the support cover plate (102), and a motor output shaft (110) of the thigh driving unit (11) and a motor output shaft (210) of the lower leg driving unit (21) penetrate through the support cover plate (102).

3. The mechanical leg of a double four-bar linkage according to claim 2, characterized in that: the lower leg driving unit (21), the thigh driving unit (11) and the side pendulum assembly (4) comprise motors.

4. The mechanical leg of a double four-bar linkage according to claim 1, characterized in that: the lower leg (24) comprises a lower leg front rotating pair (241), a lower leg rear rotating pair (242) and a lower leg shaft (243), the lower leg front rotating pair (241) and the lower leg rear rotating pair (242) are fixedly connected through the lower leg shaft (243), a lower leg rotating shaft (240) is arranged on the lower leg front rotating pair (241), and the lower leg shaft (243) is a hollow thin-walled tube.

5. The mechanical leg of a double four-bar linkage according to claim 4, characterized in that: the lower leg connecting rod (23) comprises a lower leg connecting rod front rotating pair (231), a lower leg connecting rod rear rotating pair (232) and a lower leg connecting rod shaft (233), the lower leg connecting rod front rotating pair (231) and the lower leg connecting rod rear rotating pair (232) are fixedly connected through the lower leg connecting rod shaft (233), and the lower leg connecting rod shaft is a hollow thin-walled tube.

6. The mechanical leg of a double four-bar linkage according to claim 5, characterized in that: the front turning pair (231) of the shank (24), the thigh protective shell (5) and the rotating shaft (140) of the thigh (14) are coaxially hinged, and the thigh protective shell (5) is provided with a mounting hole fixedly connected with the thigh (14).

7. The mechanical leg of a double four-bar linkage according to claim 6, characterized in that: a roller (15) is embedded in a rotating shaft (140) of the thigh (14), the roller (15) is embedded in a thigh supporting shaft (16), and the roller (15) comprises a bearing.

8. The mechanical leg of a double four-bar linkage according to claim 1, characterized in that: the sole (3) is provided with a small gap touch switch (31), the contact position of the sole (3) and the ground is provided with a grounding part (32), and the grounding part (32) is made of elastic materials.

9. The invention also provides a bionic pet dog, which is characterized in that the mechanical leg of the double four-bar linkage mechanism is as follows according to the claims 1 to 8: the bionic pet dog comprises the mechanical leg.

Background

Common mechanical dogs are classified into a rudder type and a brushless motor type according to a motor driving source. The brushless motor type mechanical dog adopts the brushless motor to drive the mechanical legs, has the characteristics of large driving force and strong load capacity, and has higher manufacturing cost, and the steering engine type mechanical dog adopts the steering engine as the driving source of the mechanical legs, has low cost and strong load capacity, can be powered by a battery, is often applied to the field of recreational accompanying robots, such as a bionic pet dog, and therefore, the mechanical dog has multiple degrees of freedom, has a bionic function, is simplified in structure, is safe, low in cost and light in weight, and is one of key technologies of the recreational accompanying mechanical dog.

The compact mechanical leg with the double four-bar linkage can better realize the goals of bionic, simplified structure, safety, low cost and light weight of an entertainment accompanying mechanical dog.

However, in the existing rudder type mechanical dog, the leg mechanisms are designed in series, that is, the steering engine for controlling leg movement is mounted on the thigh, and the steering engine for controlling leg movement is also mounted on the thigh, so that the steering engine for the thigh needs to bear a large load, and the whole leg mechanism is bulky.

In addition, a leg mechanism of the mechanical dog adopts a gear transmission design, and the gear clearance is enlarged through the leg length, so that the mechanical dog leg clearance is larger, and the mechanical error caused by the gear clearance is difficult to correct even through a software algorithm.

The Leg of the mechanical dog is designed by adopting a quadrilateral linkage mechanism, for example, the Article "Design and Control of a Novel Single Leg Structure of electric drive Quadrrudded Robot", Mingfang Chen, Hao Chen, Xuejun Wang, Jiangxan Yu, Yongxia Zhang, Hindawi, Hindawi, physical Problems in Engineering, Volume 2020, and Article ID 3943867, the thigh of the device is directly Driven by a motor, the shank is Driven by a double quadrilateral linkage, the shank has a complex Structure, the angle for controlling the shank is non-linear change, the motor can generate a phenomenon of weakness at a certain angle, and the difficulty of a Control algorithm is increased;

in addition, when the four-bar linkage mechanism of the device runs, the four-bar linkage mechanism lacks safety considerations such as a protective shell and is easy to be stuck by other objects.

Disclosure of Invention

In order to overcome the defects of the technology, the leg mechanism is designed to adopt a double four-bar mechanism, namely, one group of four-bar mechanism drives the thigh, and the other group of four-bar mechanism drives the shank, so that the mechanical leg of the double four-bar mechanism and the bionic pet dog are realized.

The invention is realized by the following technical scheme:

a mechanical leg of a double four-bar linkage mechanism mainly comprises a side swing assembly, a thigh four-bar linkage assembly, a shank four-bar linkage assembly and a sole;

the motor output shaft of the thigh driving unit is fixedly connected with the front rotary pair of the thigh driving shaft connecting rod, the rear rotary pair of the thigh driving shaft connecting rod is hinged with the front rotary pair of the thigh through the thigh connecting rod, the rotating shaft of the thigh is connected with the thigh supporting shaft through a rolling shaft, and the thigh supporting shaft is fixedly connected on the bracket;

the output shaft of a motor of a lower leg driving unit of the lower leg four-connecting-rod assembly is fixedly connected with a front rotating pair of a lower leg driving shaft connecting rod, a rear rotating pair of the lower leg driving shaft connecting rod is hinged with the front rotating pair of the lower leg through the lower leg connecting rod, a rotating shaft of the lower leg is hinged on the rear rotating pair of the thigh, and the sole is fixedly connected on the rear rotating pair of the lower leg;

the rotating shaft of the thigh and the front rotary pair of the shank driving shaft connecting rod are coaxial to a rolling shaft, and the rolling shaft is coaxial with the motor output shaft of the shank driving unit;

the side swing component is fixedly connected to the support.

Furthermore, the shank driving unit and the thigh driving unit are sequentially arranged in parallel up and down and are arranged in the bracket, the bracket is fixedly connected with the bracket cover plate, and motor output shafts of the shank driving unit and the thigh driving unit penetrate through the bracket cover plate.

Furthermore, the lower leg driving unit, the thigh driving unit and the side pendulum assembly all comprise motors.

Furthermore, the shank comprises a shank forward-rotating pair, a shank backward-rotating pair and a shank shaft, the shank forward-rotating pair and the shank backward-rotating pair are fixedly connected through the shank shaft, the shank shaft is a hollow thin-walled tube, and a shank rotating shaft is arranged on the shank forward-rotating pair.

Furthermore, the shank connecting rod comprises a shank connecting rod front rotating pair, a shank connecting rod rear rotating pair and a shank connecting rod shaft, the shank connecting rod front rotating pair and the shank connecting rod rear rotating pair are fixedly connected through the shank connecting rod shaft, and the shank connecting rod shaft is a hollow thin-walled tube.

Furthermore, the front rotating pair of the shank, the thigh protective shell and the rotating shaft of the thigh are coaxially hinged, and the thigh protective shell is provided with a mounting hole fixedly connected with the thigh.

Furthermore, a rolling shaft is embedded in the rotating shaft of the thigh and sleeved on the thigh supporting shaft, and the rolling shaft comprises a bearing.

Furthermore, the sole is provided with a small-gap touch switch, the contact position of the sole and the ground is provided with a ground contact part, and the ground contact part is made of an elastic material.

The invention also provides a bionic pet dog, which is characterized in that: the bionic pet dog comprises the mechanical leg.

The beneficial effects brought by the technical scheme provided by the embodiment of the application at least comprise:

the structure of the big leg and the small leg of the invention adopts a four-bar mechanism, the big leg and the small leg have coaxial effect, the angle change of the big leg and the small leg is converted into linear change, the workload of angle calculation is reduced, and the effect of simplifying algorithm is further achieved; the shank and shank connecting rod parts adopt hollow pipe fittings, so that the shank and shank connecting rod parts have the characteristic of light weight; the double four-bar mechanism design simplifies the structure, so that the inertia of the whole mechanical leg is small; the sole is designed by adopting elastic materials and small-gap touch switches, and the mechanical leg is more agile in action by combining a control algorithm; the safety of the pet dog is guaranteed by the protective shell of the link mechanism.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

Fig. 1 is a schematic structural diagram of a dual four-bar linkage mechanical leg according to an exemplary embodiment of the present application.

FIG. 2 is a partial cross-sectional view of a thigh four-bar linkage assembly of a dual four-bar linkage mechanical leg provided in accordance with an exemplary embodiment of the present application.

FIG. 3 is a schematic view of a shank four-bar linkage assembly of a dual four-bar linkage mechanical leg according to an exemplary embodiment of the present application.

Fig. 4 is an exploded perspective view of a dual four-bar linkage mechanical leg provided in accordance with an exemplary embodiment of the present application.

FIG. 5 is a schematic view of a lower leg link configuration of a dual four-bar linkage mechanical leg provided in an exemplary embodiment of the present application.

Fig. 6 is a lower leg structure diagram of a dual four-bar linkage mechanical leg according to an exemplary embodiment of the present application.

Fig. 7 is a schematic view of a sole structure of a dual four-bar linkage mechanical leg according to an exemplary embodiment of the present application.

FIG. 8 is a schematic diagram of a dual four-bar linkage mechanical leg and bionic pet dog, according to an exemplary embodiment of the present application.

The various reference numbers in the drawings are illustrated below:

1-thigh four-link assembly, 11-thigh driving unit, 110-thigh driving unit motor output shaft, 12-thigh driving shaft connecting rod, 121-thigh driving shaft connecting rod front rotating pair, 122-thigh driving shaft connecting rod rear rotating pair, 13-thigh connecting rod, 131-thigh connecting rod front rotating pair, 132-thigh connecting rod rear rotating pair, 14-thigh, 140-thigh rotating shaft, 141-thigh front rotating pair, 142-thigh rear rotating pair, 15-rolling shaft, 16-thigh supporting shaft, 101-bracket and 102-bracket cover;

2-a shank four-link assembly, 21-a shank drive unit, 210-a shank drive unit motor output shaft, 22-a shank drive shaft link, 221-a shank drive shaft link forward pair, 222-a shank drive shaft link forward pair, 23-a shank link, 231-a shank link forward pair, 232-a shank link backward pair, 233-a shank link shaft, 24-a shank, 240-a shank rotating shaft, 241-a shank forward pair, 242-a shank backward pair and 243-a shank shaft;

3-sole, 31-small gap touch switch, 32-touchdown;

4-a side-sway assembly;

5-thigh protective shell.

Detailed Description

To make the objects, technical solutions and advantages of the present application more clear, embodiments of the present application will be described in further detail below with reference to the accompanying drawings.

The embodiment of the application provides a double four-bar linkage mechanical leg, namely a group of four-bar linkage drives a thigh, and another group of four-bar linkage drives a shank, so that the double four-bar linkage mechanical leg and a pet dog are realized.

Example 1:

as shown in fig. 1, a mechanical leg of a dual four-bar linkage mainly includes:

the device mainly comprises a side swing assembly 4, a thigh four-bar connecting assembly 1, a shank four-bar connecting assembly 2 and a sole 3;

as shown in fig. 2, the motor output shaft 110 of the thigh driving unit 11 is fixedly connected to the front rotary pair 121 of the thigh driving shaft link 12, the rear rotary pair 122 of the thigh driving shaft link 12 is hinged to the front rotary pair 141 of the thigh 14 through the thigh link 13, the rotary shaft 140 of the thigh 14 is connected to the thigh supporting shaft 16 through the roller 15, and the thigh supporting shaft 16 is fixedly connected to the bracket 101; the thigh connecting rod 13 can be arc-shaped or linear, and the arc-shaped design is adopted in the embodiment, so that the movement range of the thigh four-link assembly is enlarged as much as possible;

as shown in fig. 3, the motor output shaft 210 of the lower leg driving unit 21 of the lower leg four-bar linkage assembly 2 is fixedly connected with the front turning pair 221 of the lower leg driving shaft linkage 22, the rear turning pair 222 of the lower leg driving shaft linkage 22 is hinged with the front turning pair 241 of the lower leg 24 through the lower leg linkage 23, the rotating shaft 240 of the lower leg 24 is hinged on the rear turning pair 142 of the upper leg 14, and the sole 3 is fixedly connected on the rear turning pair 242 of the lower leg 24;

as shown in fig. 1 to 3, the rotary shaft 140 of the thigh 14 and the front sub 221 of the lower leg drive shaft link 22 are coaxial with the roller 15, and the roller 15 and the motor output shaft 210 of the lower leg drive unit 21 are coaxial. The rotating shaft 140 of the thigh 14 of the device and the motor output shaft 210 of the shank driving unit 21 are coaxial, so that the linear change of the shank angle is ensured, and the difficulty of the algorithm is reduced.

As shown in fig. 1, the side-sway assembly 4 is secured to a support 101. In this embodiment, the side-sway component and the bracket are matched through screws (not shown in the figure);

the working principle of the mechanical leg is as follows: the thigh driving unit 11 drives a parallel four-bar linkage mechanism composed of a thigh driving shaft connecting rod 12, a thigh connecting rod 13 and a thigh 14, the thigh 14 is linearly driven to rotate in angle by changing the angle of a motor of the thigh driving unit 11, so that the leg lifting action is realized, meanwhile, the shank driving unit 21 drives the parallel four-bar linkage mechanism composed of a shank driving shaft connecting rod 22, a shank connecting rod 23 and a shank 24, the shank driving unit 21 is changed in angle to linearly drive the shank 24 to rotate in angle, so that the shank is driven to rotate backwards, meanwhile, the motor of the side swinging component 4 is rotated to drive the whole mechanical leg to realize the side swinging action, the actions are repeatedly executed, and the walking, fast walking and jumping motions are realized by adjusting different operation frequencies of the motors, as shown in fig. 8, the 12-degree-of-freedom bionic pet dog provided by one.

In summary, the double four-bar linkage mechanical leg provided by this embodiment simplifies the structure of the mechanical leg by adopting the parallel four-bar linkage structure for the big and small legs respectively, and converts the angle change of the big and small legs into a linear change, thereby reducing the workload of angle calculation.

Example 2:

in this embodiment, based on embodiment 1, as shown in fig. 4, the lower leg driving unit 21 and the thigh driving unit 11 are arranged in parallel and vertically in sequence and are disposed in the support 101, the support 101 is fixedly connected to the support cover 102, and both the motor output shaft 110 of the thigh driving unit 11 and the motor output shaft 210 of the lower leg driving unit 21 penetrate through the support cover 102.

Fig. 4 is an example in which the holder 101 and the holder cover plate 102 are fastened by screws (not shown in the figure).

As shown in fig. 4, the front rotary pair 231 of the lower leg 24, the thigh protecting shell 5 and the rotary shaft 140 of the thigh 14 are coaxially hinged, and the thigh protecting shell 5 is provided with a mounting hole fixedly connected with the thigh 14. The thigh protection case 5 of the present embodiment protects the movement of the link for safety design.

As shown in fig. 4, the rotating shaft 140 of the thigh 14 is inserted with the roller 15, the roller 15 is inserted on the thigh supporting shaft 16, and the roller 15 includes a bearing. The roller 15 is a thin-walled metal bearing or an engineering plastic bearing, and the embodiment is exemplified by a thin-walled metal bearing.

As shown in fig. 4, the lower leg drive unit 21, the thigh drive unit 11, and the side swing assembly 4 each include a motor. The motors of the lower leg driving unit 21, the thigh driving unit 11 and the side swing assembly 4 can be steering engines or brushless motors, and the steering engines are adopted in the embodiment to further control the cost of the mechanical legs.

Example 3:

in this embodiment, based on embodiment 2, as shown in fig. 5, the lower leg link 23 includes a lower leg link forward rotation pair 231, a lower leg link backward rotation pair 232, and a lower leg link shaft 233, the lower leg link forward rotation pair 231 and the lower leg link backward rotation pair 232 are fixedly connected by the lower leg link shaft 233, and the lower leg link shaft is a hollow thin-walled tube. The hollow thin-walled tube of the lower leg shaft 243 can be made of hollow aluminum tube or hollow plastic tube, and in order to reduce the weight of the mechanical leg, the embodiment is exemplified by 6mm hollow aluminum tube.

As shown in fig. 6, the lower leg 24 includes a lower leg forward rotating pair 241, a lower leg backward rotating pair 242 and a lower leg shaft 243, the lower leg forward rotating pair 241 and the lower leg backward rotating pair 242 are fixedly connected by the lower leg shaft 243, the lower leg forward rotating pair 241 is provided with a lower leg rotating shaft 240, and the lower leg shaft 243 is a hollow thin-walled tube. The hollow thin-walled tube of the lower leg shaft 243 can be made of hollow aluminum tube or hollow plastic tube, and in order to reduce the weight of the mechanical leg, the embodiment is exemplified by a 4mm hollow aluminum tube.

Example 4:

in the present embodiment, based on embodiment 1, as shown in fig. 7, the sole 3 is provided with a small gap touch switch 31, the sole 3 is provided with a ground contact 32 at the position contacting the ground, and the ground contact 32 is made of an elastic material. The elastic material of the ground contact 32 can be rubber, flexible PVC, etc.

In conclusion, the sole is made of elastic materials, the mechanical leg is elastic when being grounded, the small-gap touch switch structure is designed, the static and dynamic grounding detection function can be realized, and the elastic materials and the small-gap touch switch structure of the sole are used for facilitating the identification of complex terrains by the mechanical leg.

The above-mentioned serial numbers of the embodiments of the present application are merely for description and do not represent the merits of the embodiments.

The above description is only exemplary of the present application and should not be taken as limiting, as any modification, equivalent replacement, or improvement made within the spirit and principle of the present application should be included in the protection scope of the present application.