WO2019001100A1

WO2019001100A1 - Mobile platform

Info

Publication number: WO2019001100A1
Application number: PCT/CN2018/083456
Authority: WO
Inventors: 赵凯; 张莹; 张忆非; 李太亮; 孙俊民; 李鹏峰; 于占泉; 关红涛
Original assignee: 京东方科技集团股份有限公司
Priority date: 2017-06-27
Filing date: 2018-04-18
Publication date: 2019-01-03
Also published as: CN206870775U

Abstract

A mobile platform, comprising a vehicle frame; and at least one suspension. The suspension is installed beneath the mobile platform and comprises a shock absorber and a swing arm for use in axle installation. The swing arm is hingedly connected to the vehicle frame at a first location being an end region of a first side of the axle. The swing arm is further connected to the vehicle frame at a second location being a second side of the axle partially passing through the shock absorber such that when the swing arm swings the shock absorber can be compressed or extended. Adoption of the mobile platform of the present disclosure can reduce the risk of platform toppling during tight turns and can increase stability of the mobile platform while moving.

Description

mobile platform

Related application

The present application claims the priority of the Chinese Patent Application No. PCT Application No.

Technical field

The present disclosure relates to the field of automated guided transport vehicles, and in particular to a mobile platform.

Background technique

With the continuous development of mobile robot technology, various mobile platforms such as automatic guided transport vehicles (AGV) have been widely used in the field of manufacturing automation and automated warehouse logistics systems. Among them, as an example of the mobile platform, the omni-directional mobile AGV has received more and more attention because it can realize three degrees of freedom motion and its composite motion. Compared with the conventional AGV, the omni-directional mobile AGV can be moved in any direction and rotate at any radius, so it is very suitable for narrow spaces or where mobility is required. Among them, the omnidirectional movement of the omni-directional mobile AGV is related to the wheels it sets, and the Mecanum wheel offers the possibility of omnidirectional movement of the omnidirectional mobile AGV.

The suspensions currently used in various mobile platforms such as omnidirectional mobile AGVs are mostly non-independent suspensions. The non-independent suspension has the advantages of simple structure, low cost, high strength, easy maintenance, and small change in wheel position during driving. . One of the non-independent suspensions is characterized in that the wheels on both sides are connected by an integral axle, and the wheels, together with the axle, are suspended below the frame or body by an elastic suspension system. However, the non-independent suspension connected by the integral axle is easy to drive the whole vehicle to sway when driven or swayed by a driving wheel, so that the comfort and steering stability are poor. Another non-independent suspension is characterized in that the frame and the axle are connected by a connecting shaft and a sleeve for the connecting shaft to move up and down. The connecting shaft and the sleeve are arranged such that the distance between the frame and the ground The higher the center of gravity of the omni-directional mobile platform is higher than the ground, which increases the chance that the omni-directional mobile platform will tip over when cornering.

In addition, some advanced omni-directional mobile platforms use a self-service adjustment suspension to detect the road ahead through various sensors. The computer controls the suspension to move up and down according to the signal detected by the sensor to keep the frame at a level. The upper and lower moving devices that control the up and down movement of the suspension mostly use hydraulic cylinders and the like to cause the vehicle body to be heavier, and the suspension structure is complicated and costly, and the suspension is currently applied less.

Public content

In view of this, an embodiment of the present disclosure provides a mobile platform that is simple and compact in structure, convenient in operation, and stable in operation. The mobile platform includes: a frame; and at least one suspension disposed under the frame and including a shock absorber and a swing arm for mounting the axle. The swing arm is hinged to a first position of the frame at an end of the first side of the axle, and the portion of the swing arm passing the shock absorber and the frame at a portion of the second side of the axle The second position is coupled such that the damper can be compressed or stretched when the swing arm is swung.

As an example, the portion of the swing arm that extends beyond the damper toward the second side at a portion of the second side of the axle forms a protrusion that is at least partially located in the vehicle Below the third position of the frame, when the swing arm is pivotally moved relative to the first position of the frame, the extension can be brought into contact with the third position of the frame by the elastic buffer.

As an example, the mobile platform further includes four wheels, and the suspension is four, which are respectively disposed corresponding to the respective wheels.

As an example, the mobile platform further includes a motor bracket for setting an electric motor that drives the axle, the motor bracket being fixedly coupled to an axially inner side of the swing arm.

As an example, the angle between the portion of the swing arm on the first side of the axle and the portion on the second side of the axle is an obtuse angle.

As an example, the portion of the swing arm on the first side of the axle is obliquely downward, the portion of the swing arm on the second side of the axle is horizontally disposed, and the pendulum The arm also includes an axle mounting portion between the portion of the first side of the axle and the portion of the second side.

As an example, the elastic buffer body is a spring pad or a rubber pad or an air cushion fixedly disposed on at least one of the following: a lower surface at the third position of the frame Upper; on the upper surface of the protrusion.

As an example, the spring pad or rubber pad or air cushion has a thickness of 3 mm to 8 mm.

As an example, a portion of the projection at least below the third position of the frame is made of an elastic material as the elastic buffer.

As an example, the portion of the swing arm on the first side of the axle is a hollowed out structure.

Compared with the prior art, the mobile platform of the present disclosure has the beneficial effects that the swing arm is hinged to the first position of the frame at one end of the axle, and the swing arm passes the shock absorber on the other side of the axle. The connection with the second position of the frame can reduce the height of the moving platform, reduce the center of gravity of the mobile platform, reduce the risk of the mobile platform falling during sharp turns, and the hinged end of the swing arm and the frame are non-rigidly connected. Improve the motion stability of mobile platforms.

DRAWINGS

1 is a schematic structural diagram of a mobile platform according to an embodiment of the present disclosure;

Figure 2 is a schematic view showing the partial structure of the A direction of Figure 1;

3 is a schematic view showing a partial structure of the B direction of FIG. 1.

Detailed ways

The mobile platform of the present disclosure is further described in detail below with reference to the accompanying drawings and specific embodiments, but is not intended to limit the disclosure.

Referring to FIG. 1 , an embodiment of the present disclosure discloses a mobile platform, including: a frame 1 ; a suspension, the suspension is disposed under the frame 1 , and the suspension includes a shock absorber 2 and a swing arm for mounting the axle 3 4. Among them, the shock absorber 2 can be selected from a hydraulic shock absorber or a pneumatic shock absorber, and the selection of the shock absorber 2 can be determined according to the overall design of the mobile platform.

Referring to Figures 2 and 3, the end of the swing arm 4 on the first side of the axle 3 is hinged to the first position 12 of the frame 1 such that the end of the swing arm 4 on the first side of the axle 3 can be opposite to The first position 12 of the frame 1 is pivotally moved, and the portion of the swing arm 4 on the second side of the axle 3 is connected to the second position 13 of the frame 1 via the damper 2. Specifically, in order to realize pivotal movement of the swing arm 4 relative to the frame 1, the shock absorber 2 can be compressed or stretched when the swing arm 1 is swung, for example, the swing arm 4 is in the second of the axle 3 The side portion is hinged or fixedly connected to the lower end of the damper 2, and the upper end of the damper 2 is connected to the second position 13 of the frame 1 in an articulated manner. Of course, the connection of the damper 2 to the frame 1 at the second position 13 can also be achieved in other ways, as long as the pivoting movement of the swing arm 4 can be achieved and the damper 2 can be made during this pivoting movement. Compress or stretch. Note that, as an example, as shown in FIG. 2, the first position 12 is a position outside the longitudinal (front-rear direction) axle 3 of the moving platform, and the second position 13 is inside the longitudinal (front-rear direction) axle 3 of the moving platform. s position. Of course, the first position 12 and the second position 13 can also be reversed without affecting the implementation of the present disclosure.

Specifically, the swing arm 4 has a cylindrical shape at the end of the first side of the axle 3, and the first position 12 of the frame 1 has two downwardly projecting plate members, each of which has a mounting hole. The cylindrical end of the swing arm 4 is mounted between the two plate members, and passes through the mounting holes of the two plate members and the opening of the cylindrical end of the swing arm 4 through the screw 10 to swing the arm 4 is hinged to the first position 12 of the frame 1 at the end of the first side of the axle 3 . Similarly, the two ends of the damper 2 can be connected to the second position 13 of the frame 1 and the swing arm 4 on the second side of the axle 3, that is, as shown in FIG. 3, the damper 2 The two ends are respectively cylindrical (or arranged to include a sleeve), and the second position 13 of the frame 1 and the portion of the swing arm 4 on the second side of the axle 3 respectively have two plate-like members extending parallel to each other. Each of the plate members has a mounting hole, and the cylindrical portions at both ends of the damper 2 are respectively hinged by screws 10 between the two pairs of plate members. Of course, the portion of the swing arm 4 on the second side of the axle 3 in Fig. 3 can also be fixedly coupled to the lower end of the damper 2, rather than a movable connection such as a hinge. In this connection, when the swing arm 4 is pivotally moved relative to the frame 1, the swing arm 4 is rotated about the pivot (eg, the screw 10) at the first position 12 at the end of the first side of the axle 3, Thereby, the swing arm 4 is moved up and down on the second side of the axle 3, so that the damper 2 connected to the swing arm 4 on the second side of the axle 3 is compressed or stretched. In addition, in order to make the swinging effect of the swing arm 4 and the first position 12 of the frame 1 better, a bearing can be provided between the screw 10 and the cylindrical end of the swing arm 4.

Here, the first side of the axle 3 refers to the side of the axle 3 that faces the outer side in the longitudinal direction of the moving platform; and the first side of the axle 3 refers to the side of the axle 3 that is directed to the longitudinal inner side of the moving platform. In addition, the swing arm 4 is respectively on the first side and the second side of the axle 3: a swing arm 4 is directly coupled to the frame 1 at the first position 12, and the swing arm 4 is on the first side of the axle 3, and the frame 1 is in the first The two positions 13 are hinged by the damper 2 and are referred to as swing arms 4 on the second side of the axle 3. 1 shows that the front and rear swing arms 4 are located on the longitudinal outer side of the moving platform at the first side portion of the axle 3, and the front and rear swing arms 4 are located on the longitudinal inner side of the moving platform at the second side portion of the axle 3. Of course, at least one of the front and rear swing arms 4 may be disposed on the longitudinal inner side of the moving platform on the first side portion of the axle 3 according to the actual situation, and at least one of the front and rear swing arms 4 may be disposed on the second side portion of the axle 3 The longitudinal outer side of the mobile platform.

In the mobile platform of the present disclosure, the swing arm 4 is directly hinged to the first position 12 of the frame 1 at the end of the first side of the axle 3, and the portion of the swing arm 4 at the second side of the axle 3 passes through the damper 2 The second position 13 of the frame 1 is connected, which can reduce the total height of the moving platform, reduce the center of gravity of the moving platform, reduce the risk of the mobile platform falling when the sharp turn is made, and the end of the swing arm 4 and the frame 1 are hinged. Non-rigid connection for improved motion stability of the mobile platform.

According to an aspect of the present disclosure, as shown in FIGS. 2 and 3, the portion of the swing arm 4 on the second side of the axle 3 extends beyond the damper 2 toward the second side to form a projection 5, the projection 5 being at least Partially located below the third position of the frame 1, wherein the third position of the frame 1 may be a position of the frame 1 that extends downwards near the second position 13. When the swing arm 4 is pivotally moved at its hinge at its hinge relative to the first position 12 of the frame 1, the extension 5 can be brought into contact with the third position of the frame 1 by the elastic buffer. Thus, when the pivotal movement of the swing arm 4 exceeds the stroke limit of the damper 2, the elastic cushion body and the damper 2 can exert a double shock absorbing effect.

Specifically, as shown in FIG. 2 and FIG. 3, for example, the moving platform is perpendicular to the axle 3 to the left (the term "left" is defined herein in the left-right opposite direction, not limited to the left-hand side). For example, taking the wheel at the position of arrows A and B in FIG. 1 (not shown in FIG. 2-3) as an example, when the wheel encounters an obstacle rise, the swing arm 4 is counterclockwise around the hinge of the first side of the axle 3 Rotate and compress the shock absorber 2. Under the combined action of the elasticity and damping of the shock absorber 2, the center of gravity of the mobile platform and the step response amplitude of the mobile platform as a whole can be reduced, thereby reducing the impact on the mobile platform and maintaining relatively stable. If the obstacle is too large, the compression stroke of the damper 2 exceeds the first working stroke limit of the set suspension, at which time the extension 5 of the swing arm 4 comes into contact with the third position of the frame 1 via the elastic buffer. Since the elastic buffer body has elasticity and damping, at this time, the shock absorber 2 and the elastic buffer body work together to achieve double shock absorption, and the impact on the moving platform can be reduced, and the suspension is at the second working stroke. The working stroke of the suspension includes two parts. When the suspension pivots in the first working stroke, the shock absorber 2 acts as a spring and a damping force, which can achieve the first stage damping effect; when the suspension exceeds the first work formation At the limit, when the pivoting movement in the second working stroke, the shock absorber 2 and the elastic buffer body jointly exert the damping effect, that is, double damping, and the second-stage damping effect can be achieved. The first stage damping and the second stage damping are used to realize the secondary damping design of the suspension, which can ensure the smooth running of the vehicle. During the operation of the mobile platform to the left, a low squat is encountered. Under the action of the spring of the damper 2, the swing arm 4 swings clockwise, and the wheel is lowered to quickly contact the ground, thereby keeping the moving platform moving smoothly.

Illustratively, the elastic buffer body is a spring pad or a rubber pad or an air cushion, and the spring pad or rubber pad or air cushion is fixedly disposed on at least one of the following: the lower surface at the third position of the frame 1; On the upper surface of the portion 5. Thus, when the swing arm 4 is pivotally moved relative to the first position 12 of the frame 1, the extension 5 can pass the spring pad or rubber pad or air cushion to the frame 1 during the second working stroke of the suspension. Three-position contact.

Illustratively, the spring pad or rubber pad or air cushion has a thickness of from 3 mm to 8 mm, for example 5 mm. As shown in FIGS. 2 and 3, when the distance between the upper surface of the projecting portion 5 of the swing arm 4 and the lower surface of the third position of the frame 1 is 5 mm, the thickness of the spring pad or the rubber pad or the air cushion is also 5 mm. When the swing arm 4 is pivotally moved, the suspension can be directly operated in the aforementioned second working stroke to achieve double shock absorption. In addition, when the two sides of the spring pad or the rubber pad or the air cushion are in close contact with the lower surface at the third position of the frame 1 and the upper surface of the protrusion 5, respectively, even if the swing arm 4 is engaged with the hinge of the frame 1 Accuracy (such as due to manufacturing or wear) is not high enough to cause a relative slip in addition to the pivoting motion, and the spring pad or rubber pad or air cushion will also rub against the third position and the extension 5 of the frame 1, limiting the pendulum The sliding of the arm 4 enables smooth operation of the mobile platform.

Illustratively, another arrangement of the elastic buffer body is such that at least a portion of the extension 5 below the third position of the frame 1 is made of an elastic material as an elastic buffer, an elastic buffer body and an extension The part 5 is fixedly connected. With the elastic buffer body of this arrangement, when the suspension is at the second working stroke, the bending deformation of the elastic buffer body can achieve a better shock absorption effect.

Referring to Fig. 1, in the embodiment, four suspensions are provided corresponding to the respective wheels. Among them, if the wheel is a Mecanum, the mobile platform can move in all directions. An axle 3 is disposed on each suspension, and an outer end of the axle 3 is provided with a wheel, and an inner end of the axle 3 is connected to an output shaft of the motor 11 for driving the wheel through a coupling, that is, the motor 11 can be set to four, respectively The wheel corresponds to the setting. The four wheels operate independently, and the above motion can be repeated when encountering the obstacles and low-lying points mentioned above, and the shock absorption is independently performed. The shock absorption actions of the shock absorber 2 and the elastic buffer body do not affect each other, and the non-independent is overcome. When a driving wheel is driven or shaken in the suspension, it is easy to drive the sway of the whole moving platform, and the stability and maneuverability of the mobile platform are improved, so the adaptability to the road surface is improved.

Illustratively, referring to FIG. 2, the suspension further comprises a motor bracket 6 for arranging an electric motor 11 for driving the axle 3, the motor bracket 6 being fixedly coupled to the axially inner side of the swing arm 4, so that the electric motor 11 is also disposed at the swing arm 4. The axially inner side saves the intermediate part below the frame 1 and saves space for the setting of the control system of the mobile platform. Further, as shown in FIG. 1, the intermediate portion below the saved frame 1 may be provided with a battery 7 that powers the motor 11 and a motor driver 8 that controls the motor 11. In order to operate the mobile platform accurately, a distance sensor 9 is also provided on the mobile platform, and the distance sensor 9 may be plural. Illustratively, the distance sensors 9 may be distributed on each side of the frame 1 of the mobile platform in order to control the mobile platform, in particular the omnidirectional mobile platform, in a suitable position in space, for example to avoid contact with obstacles on each side. Or collision.

As shown in FIGS. 2 and 3, in one embodiment, the swing arm 4 has an obtuse angle between the portion on the first side of the axle 3 and the portion on the second side, that is, an angle L greater than 90 degrees. shape. Of course, the angle can also be a right angle or an acute angle. However, the structure of the swing arm 4 having an obtuse angle can save material with respect to the swing arm 4 having a right angle or an acute angle, and in the pivotal movement of the swing arm 4, the hinge of the axle 3 on the first side thereof can be ensured. The movement between the damper 2 and the second position 13 of the frame 1 is moved.

Illustratively, as shown in FIGS. 2 and 3, the portion of the swing arm 4 on the first side of the axle 3 is inclined downward, and the portion of the swing arm 4 on the second side of the axle 3 is horizontal, and the pendulum The arm 4 further includes an axle mounting portion between a portion of the first side of the axle 3 and a portion of the second side, the swing arm 4 being a longitudinal swing arm that is perpendicular to the axial direction of the axle 3 . The structure of the swing arm 4 is angled, and the portion on the second side of the axle 3 is horizontal, and the shock absorber 2 and the elastic buffer body of the suspension are matched, and a certain degree of swing does not affect the shaft spacing, and the running accuracy of the mobile platform can be controlled. Improve the accuracy of manipulation.

Illustratively, the portion of the swing arm 4 on the first side of the axle 3 is a hollow structure, which can save material on the basis of ensuring the strength of the swing arm 4.

The above embodiments are merely exemplary embodiments of the present disclosure, and are not intended to limit the disclosure, and the scope of the disclosure is defined by the claims. A person skilled in the art can make various modifications or equivalents to the present disclosure within the spirit and scope of the disclosure, and such modifications or equivalents are also considered to fall within the scope of the present disclosure.

Claims

A mobile platform that includes:

a frame; and

At least one suspension, disposed under the frame and including a shock absorber and a swing arm for mounting the axle,

Wherein the swing arm is hinged to a first position of the frame at an end of the first side of the axle, and the swing arm passes the shock absorber and the vehicle at a portion of the second side of the axle The second position of the frame is coupled such that the damper can be compressed or stretched when the swing arm is swung.
The mobile platform according to claim 1, wherein a portion of the swing arm on the second side of the axle extends beyond the damper toward the second side to form a protrusion, the extension The outlet is at least partially located below the third position of the frame, the protrusion being capable of passing the elastic buffer body and the vehicle when the swing arm is pivotally moved relative to the first position of the frame The third position of the frame is in contact.
The mobile platform according to claim 1, wherein the mobile platform further comprises four wheels, and the suspension is four, respectively disposed corresponding to the respective wheels.
The mobile platform according to claim 1, wherein said moving platform further comprises a motor bracket for setting an electric motor for driving said axle, said motor bracket being fixedly coupled to an axially inner side of said swing arm.
The mobile platform of claim 2, wherein an angle between a portion of the swing arm on a first side of the axle and a portion on the second side of the axle is an obtuse angle.
The mobile platform according to claim 5, wherein a portion of the swing arm on the first side of the axle is obliquely downward, and a portion of the swing arm on the second side of the axle It is horizontally disposed, and the swing arm further includes an axle mounting portion between the portion of the first side of the axle and the portion of the second side.
The mobile platform according to claim 2, wherein the elastic buffer body is a spring pad, a rubber pad or an air cushion, and the spring pad, the rubber pad or the air cushion is fixedly disposed on at least one of the following: the frame On the lower surface at the third position; on the upper surface of the projection.
The mobile platform of claim 7, wherein the spring pad, rubber pad or air cushion has a thickness of from 3 mm to 8 mm.
The mobile platform according to claim 2, wherein a portion of the projection at least below the third position of the frame is made of an elastic material as the elastic buffer.
The mobile platform of claim 6, wherein the portion of the swing arm on the first side of the axle is a hollow structure.
The mobile platform of claim 5 wherein the swing arm is located longitudinally outward of the mobile platform at a first side portion of the axle.