JPS62128833A - Steering mechanism for omnidirectional mobile car - Google Patents

Abstract

PURPOSE:To enable total control of single drive unit without discriminating between travelling and steering purposes by providing a means for distributing the outputs from a drive means and distributing the outputs for driving a wheel and for driving a steering. CONSTITUTION:The outputs from the first and second drive units 27, 28 are distributed by means of a differential unit 24 and transmitted to the wheels 23a-23d. Under a travel mode, both drive units 27, 28 are driven simultaneously to control such that the rotations of the driven pulleys 34a-34d and 35a-35d will be same. Consequently, the rotations of the steering shafts 21a-21d are brought to zero. Then under a steering switch mode, only the drive unit 27 is drive to rotate only the wheels 23a-23d around the steering wheels 21a-21d, changing the travelling direction. Consequently, travelling and switching of direction can be carried out by single type of drive units 27, 28.

Description

[Detailed Description of the Invention] [Technical Field of Departure IJ] This Departure IJ+ has a plurality of steering mechanisms (one wheel for an omnidirectional fJJ small steering mechanism that runs by turning the wheels in any direction).
do.

[Background of the Invention] In general, movement 11 (traveling on the floor with 11 wheels) involves moving while changing the direction of the vehicle body by steering the front wheels.
I-type movement-1 (and all 1) Omni-directional movement 1 (which moves in all directions, forward, backward, left, right, and diagonally without changing the direction of the vehicle body by changing the direction of the wheels) , the above-mentioned vehicle-type mobile IT- has a large turning radius when changing the direction of travel, so it can be used as a mobile vehicle that moves while changing direction even in a narrow space between desks, such as an office robot, or as a designated mobile vehicle. This is suitable for vehicles that move according to complex movement patterns, or vehicles that are required to make sharp turns I!j!', ';-. Omnidirectional movement 1 (in which the i'lj body moves in all directions without changing its orientation) is used.

[Prior Art 1] As a steering mechanism for omnidirectional movement/1 (as described in 1-1), there is conventionally a steering mechanism configured as shown in FIGS. 5(A) and 5(B). The mechanism is
Four cylindrical steering shafts 2, φ, are provided on the insect body L directly through bearings 2alIa, and a rubber tire is attached to each of the small bearings 3 at the lower end of the steering shaft 2, the fist. When the wheels 4, φ, consisting of a hat are rotatable, the -F- of each steering shaft 2◆, ψ is fixed.
, a steering pulley 5...φ is provided in each section,
A wooden belt 8 is connected to the pulleys 5 and 1 (the drive pulley 7 of the steering drive device 6 provided on the rolling body l).
By winding the wheels and rotating each steering shaft 2 by a predetermined angle using the steering drive device 6, the direction of all wheels 4 (wheels 4) is changed and the running direction is changed. Traveling in all directions +p is +lj body I
Each +iL wheel 4...
This is done by driving the That is, wheel 4! [(A bevel gear 10 is sunk in each of the shafts 4a..., and a bevel gear 10 is provided in the rotating shaft fk within the steering shaft 2 via hair rings 11a, lla. The umbrella mjl'E12 of the drive shaft 11 (-) is engaged with the upper end of the drive shaft 11, and the upper end of the drive shaft 11 protrudes above the steering shaft 2, and a pulley 13 is provided at each of the protruding parts. . . . and a drive pulley 15 provided on the traveling drive device 9 on the vehicle body l, and a belt 14.
is wound. Therefore, when the driving pulley 15 is rotated by the traveling drive device 9, the rotation is caused by the rotation of the belt 14.
is transmitted to each pulley 13---, thereby causing each drive shaft 11... to rotate, and this rotation mutually ll1ii
It is transmitted to each city shaft 4a through meshing bevel gears 10, 12, and the wheels 4 rotate and travel, respectively.

However, in such a steering mechanism, the steering drive device ri 6 and the travel drive device 9 are independently required, and each drive device 6.9 has a different output. The output (power) of the drive device 9 is large.

Therefore, two types of drive devices (motors) are required, parts management is complicated, assembly work is troublesome, and costs are high.

[Part 1 of the invention] This invention was made in consideration of the above-mentioned =rG circumstances, and its purpose is to use one or one type of drive device ′ξ for steering and for traveling. Omnidirectional movement with total control without distinguishing between
8 [9, Key Points] To achieve the above-mentioned objects, the present invention provides a means for achieving the above-mentioned object by providing a steering mechanism for transmitting the signal to the distribution stage by -1( to the distribution F stage. The steering wheel is divided into one for driving the wheels and one for driving the steering wheel for changing the angle of the steering shaft.

[Configuration of Embodiment] An embodiment of the present invention will be described below with reference to FIGS. 1 to 4.

FIGS. 1A to 1C show omnidirectional movement iji.

The vehicle body 20 of this omnidirectional vehicle has four steering shafts 21a to 21d with bearings 22 and 22 located near the four corners, respectively.
It is rotatably provided via... The steering shafts 21a to 21d each have a cylindrical shape, and wheels 23a to 23d and a differential gear 24 are provided at the bottom thereof. As shown in FIG.
11 rotatably attached to the bearing 25 via bearings 26a, 26a (23 rotates integrally with the shaft 26).
d is arranged at a position offset by a predetermined distance r from the axis center of each of the steering shafts 21a to 21d. In addition, the differential device 24... is a first drive device 27.2 and a second drive device 27.2, which will be described later.
It distributes the output of 8, and the distributed output is divided into 11 (
The transmission is transmitted to the wheels 23a to 23d to drive and rotate the wheels 23a to 23d as appropriate, and all have the same configuration. Here, the differential device 24 shown in FIG.
I will explain about it. This differential device 24 is provided on the steering shaft 21a, and includes a driven bevel gear 29 attached to the wheel 26, and first and second drive bevel teeth V2O, 31 that mesh with the driven bevel gear 29. The first drive bevel gear 30 is attached to a cylindrical drive shaft 32 rotatably provided in the steering wheel 1a via bearings 32a, 32a, and the second drive bevel gear 31 is A bearing 33 is disposed within the drive shaft 32 of the first drive bevel gear 30.
It is attached to the drive shaft 33 which is rotatably provided through the shafts 33a and 33a. In this case, the first drive shaft 32, fist,
At the upper end, as shown in FIG. 1(B), first driven pulleys 34a to 34d are provided, and a second
The drive shafts 33... have one end connected to the first drive shaft 3, respectively.
-1 of 2 protrudes to one side, and the second part is placed on this protruding part.
Following pulleys 35a to 35c+ are provided.

On the other hand, the first and second drive devices 27 and 28 are completely the same and consist of a motor, a speed reducer, an encoder, etc.
As shown in Figure (A), the drive pulley 36 is attached to the output shaft 27a of the first drive device 27,
A first transmission belt 37 is wound around the first driven pulleys 34a to 34d.
4a to 34d.

Similarly, a drive pulley 38 is attached to the output shaft 28a of the second drive device 28, and a second transmission belt 38 is attached to the drive pulley 38 and the second driven boos 935a to 35d.
9 is wound around the transmission belt 39, and the rotation of the drive pulley 38 is transmitted to the driven pulleys 35a to 35d of each node 2 by this transmission belt 39.

[Function on the Flow Side] Next, the operation of the omnidirectional movement east steering mechanism configured as described below will be described with reference to FIGS. 2 and 3.

In this case, the first driven pulleys 34a to 34d rotated by the first drive device 27 and the second driven pulleys 35a to 35d rotated by the second drive device 28 are
As shown in Figure (A), it is assumed that the first driven pulleys 34a to 34d rotate in the opposite direction every
, the rotation speed of the second driven pulleys 35a to 35d is N2, and the steering shafts 21a to 21, which are the differential arms of the differential device 24, are set to N2.
The rotation speed of wheel d is NS, and the rotation speed of each wheel 23a to 23d is Nr.
The number of teeth is 229. The first driving bevel ILF 30 and first, a full interview! i! The driving mode in which the jj is driven will be explained. In this case, the first and second drive units '1127.28 equipped with encoders are simultaneously driven, and the rotational speed N of the first driven pulleys 34a to 34d is
and the rotation speed N2 of the second driven pulleys 35a to 35d.
The servo control is performed so that the rotational speed becomes N (N=N+=N2). Then, as shown in FIG. 2(B), the rotation speed N9 of the steering shafts 21a to 21d, which are differential arms, becomes zero (Ns'=O), and the steering shaft 21
a to 21d do not rotate, but 11 (wheels 23a to 23d
The rotation speed NI is N・Z3o/Z, +q, and each +li
Since the wheels 23a to 23d rotate, the omnidirectional movement L moves straight.

In addition, we will explain the omnidirectional movement/steering turn (+ mode) that changes the direction of the 1st.
The first driven pulley 34 is driven only by the driving device 27 of the
a to 34d are rotated l+1 at the rotational speed N (N=N+), and the second drive device 28 is stopped.
The rotational speed NS of the wheel 1d and the rotational speed N1 of the wheels 23a to 23d are determined by a certain ratio (NT /Ns = 2・r
/d, where d is -1 (diameter of the ring), +
While the lj wheels 23a to 23d are rolling, the steering shaft 2
1a to 21d also rotate. Therefore, the steering shaft 2
1a to 21d do not move, and wheels 23a to 23
Only wheel d rolls around the steering shafts 21a to 21d, and its transfer direction (orientation of the ltf wheels) changes, so the running direction of the omnidirectional movement i1j is changed.

Note that, in cases other than the above two conditions, the omnidirectional movement i1i performs a composite operation in which the steering shafts 21a to 21d rotate at a certain speed and travel at a certain speed while changing the running direction.

By the way, the above-mentioned differential device 24 will be explained in more detail with reference to Table 1 shown below.

Table 1 However, Za in Table 1 is the number of teeth Zo of the first drive Imaichi 1130.
o, and zb is the number of teeth of the driven bevel gear 29, 229.

Such a differential type′j! At step 124, the number of revolutions N! of the first driven pulley 34a is determined by the "gluing method"! , the rotation speed N2 of the second driven pulley 35a, the rotation speed NS of the steering shaft 21a which is the differential arm of the differential device 24, and each wheel 2.
3a - 23d rotation * N t Find the relationship.

Nl = NS +k - (1) N2 =
-NS +ka * * (2) N1=kIIZ3o/Z
2-J #・@(3), (1) If we eliminate k from equation (2).

Ns = (1/2) · (NT - N2 ), and when NS is deleted, NT = (1/2) · (NTN2) · (230/Z2
9).

Therefore, when the omnidirectional vehicle changes direction (rotates the steering shaft), N5 = N/2 NT = (N/2) · (23G/Z29), and the first drive bevel gear 30 The ratio between the number of teeth Z3o of the driven bevel gear 29 and the number of teeth 729 of the driven bevel gear 29, and the radius of the wheel (d
/2) and the eccentric distance r of the wheel are set equal, J: (2:10/Z, ?9) = (
Substitute d/2)/r. Then, (Nt/N=)=2·r/d.

By the way, as mentioned above, if a wheel with diameter d is placed offset from the center of the steering shaft by a distance r, then when the steering shaft rotates by OS, the wheel must roll by rθS. , Or = r OS/ (d/2) θI/θq=2・r/d. Therefore, it is proved that (NT /Ns) = 2 @r/d is a necessary condition, and the above omnidirectional A steering switching mode that changes the direction of a moving vehicle satisfies this condition.

According to the steering mechanism for an omnidirectional vehicle as described in 1 above, since the omnidirectional vehicle can travel and change direction with one type of drive device 27, 28, parts management and assembly work can be simplified. Simplification can be achieved. In particular, since the differential device 24 controls the outputs of the two drive devices 27 and 28, there is no need to use a device with a large output as in the past, and a device with a small output is sufficient, reducing costs. You can also do that.

Note that the present invention is not limited to the above-mentioned embodiments, but also includes, for example, the fourth embodiment.
As shown in the figure, steering shafts 21a to 21d provided with a clutch 40 may be driven. That is, the drive device 41 includes a motor, a speed reducer, and a motor, and is provided on the lower surface of the vehicle body 20. A bevel gear 42 is provided on one output shaft 41a of the drive device 41, and a support shaft 36a of the first drive pulley 36 is attached to the bevel gear 42.
The bevel gears 43 provided in are meshed with each other. Further, a clutch 40 is connected to the other output shaft 44 of the drive device 41. A bevel gear 45 is provided on the output shaft 40a of the clutch 40, and a bevel gear 46 provided on the support shaft 38a of the second drive pulley 38 meshes with the bevel gear 45. Therefore, when the drive device 41 operates and the clutch 40 is connected, each bevel gear 4
2.43 and 45.46, the first and second drive pulleys 36.3B rotate.

It operates in exactly the same way as in the driving mode of the embodiment described above, and causes the omnidirectional vehicle to move straight. The drive device 41 operates, but when the clutch 40 is disconnected, it operates in exactly the same way as in the steering control mode of the embodiment described above, changing the traveling direction of the omnidirectional vehicle. .

Furthermore, - in the embodiment described above, the driving device 'j! I27.28
Although the rotation is transmitted by a transmission bell h37.39, this 91-degree rotation is not limited to this, and it goes without saying that a southeast mechanism, a link mechanism, a chain, etc. may be used.

[Effects of IJI] As explained above, according to the steering a structure of an omnidirectional moving vehicle related to this IJI, the output from the drive means provided in the vehicle body is transmitted to the distribution f stage by the transmission slave, and ,
Since the distributing means is used to divide the drive device into a wheel drive device that drives and rotates the Ilj wheels and a steering drive device that changes the angle of the steering shaft, one or one type of drive device is differentiated into one for steering and one for driving. It is possible to control the parts in total without having to worry about them, and therefore it is possible to streamline the work etc. by parts management and assembly.
It is also possible to reduce costs.

[Brief explanation of drawings]

1 to 3 show one embodiment of the present invention, FIG. 1(A) is a plane 1 of the omnidirectional moving vehicle, and FIG. 1(B) is a sectional view taken along the line AA, Diagram (C) shows the steering shaft 21
Fig. 2(A) is a diagram showing the basic configuration of the differential gear; Fig. 52(B) is a diagram showing its driving mode state; Fig. 2(C) is a diagram showing its direction change mode state. 3 is a diagram showing an example of the movement of an omnidirectional vehicle, FIG. 4 is a diagram showing a modified example, FIG. 5 is a conventional example, and FIG. FIG. 5(B) is a sectional view taken along line B-B. 201111-Vehicle body, 21a-21d*s*Steering shaft, 23a-23d1111-Wheel, 24
... fist differential device, 27... first drive device,
28...Second drive device, 37.39・φ・Transmission belt. Figure 1 (A) Initial car 0 plane concavity Figure 1 (C) Steering wheel q゛shaft page enlarged interior Figure 3 (A) Conventional map of the same department, Dongmenmian map B-8匈1荀門

Claims (1)

[Claims] Omnidirectional movement in which a vehicle body is rotatably provided with a plurality of steering shafts, each of the plurality of steering shafts is provided with at least one or more wheels, and each wheel is turned in an arbitrary direction to travel. A steering mechanism for a vehicle, comprising: a drive means for driving at least the wheels and a steering shaft; a distribution means for distributing the output from the drive means into a wheel drive and a steering drive for changing the angle of the steering shaft; A steering mechanism for an omnidirectional vehicle, comprising: a transmission means for transmitting power output from the drive means to the distribution means.