Differential control system and method for double-axle steering

Abstract

The differential control system comprises a vehicle frame, two sets of steering mechanisms are arranged on the lower side of the vehicle frame, each steering mechanism comprises a driving wheel and a driven wheel which are connected with a vehicle body in a running fit mode, and the driving wheels are arranged diagonally and located on the front right portion and the left rear portion of the vehicle; in the first step, during linear driving, the same speed is issued to the driving wheels, and linear movement can be achieved; 2, when the vehicle turns left and right, differential speed calculation is carried out, the speed ratio of the driving wheels on the front side and the rear side can be regarded as the ratio of the distance L1 from the center of the front driving wheel to the rotation center to the distance L2 from the center of the rear driving wheel to the rotation center, and formula calculation comprises the following parameters: the angle 1 of the driving wheels on the front side, the angle 2 of the driving wheels on the rear side and the distance Length between the centers of the front wheel and the rear wheel; and the rotating speeds of the driving wheels on the front side and the rear side are calculated through formula matching according to the center distance Width of the left wheel and the right wheel and the speed ratio of the driving wheels on the front side and the rear side, and differential adjustment of the double-axle steering mode, the front axle steering mode and the rear axle steering mode is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of vehicle steering mechanisms, in particular to a differential speed control system and method for dual-bridge steering. Background Art

[0002] The vehicle will perform turning operations. The vehicle drive is generally divided into dual-axle drive, front-axle drive and rear-axle drive. In different drive modes, the vehicle can turn left and right. When turning left and right, the two wheels will have a speed difference. The existing technology uses differential control to perform differential control on the two wheels of the steering wheel, and generally a differential is set. However, in AGV power vehicles, due to the need to take into account the requirements of power flexibility, differentials are not used. It is very necessary to perform differential control on each individual power wheel and driven wheel, and people have conducted a lot of research on this. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a differential control system and method for dual-axle steering, which provides differential control of driving wheels and driven wheels in dual-axle, front-axle and rear-axle driving modes to achieve good steering function.

[0004] The present invention is realized by the following technical scheme: A differential speed control method for dual-axle steering of the present invention comprises a vehicle frame, two sets of steering mechanisms are arranged on the lower side of the vehicle frame, the steering mechanisms comprise driving wheels and driven wheels connected to the vehicle body for rotation, the driving wheels are arranged diagonally and are located at the front right and left rear of the vehicle; the characteristics are:

[0005] The first step is to send the same speed to the driving wheel when driving in a straight line, so that it can move in a straight line;

[0006] The second step is to calculate the differential speed when the vehicle turns left and right. The ratio of the front and rear drive wheel speeds can be regarded as the ratio of the distance L1 from the center of the front drive wheel to the center of rotation to the distance L2 from the center of the rear drive wheel to the center of rotation, that is, The formula calculation includes the following parameters: the front driving wheel angle angle1, the rear driving wheel angle angle2, the front and rear wheel center distance Length, the left and right wheel center distance Width and the ratio of the front and rear driving wheel speeds. The formula matching is used to calculate the rotation speed of the front and rear driving wheels to achieve differential adjustment of the dual-axle steering mode, front axle steering mode and rear axle steering mode.

[0007] Further technical solution, in the dual-axle steering mode, the ratio of the front drive wheel speed to the rear drive wheel speed is calculated.

[0008]

[0009] When driving in a straight line, send the same speed S to the front and rear drive wheels;

[0010] When turning left, the front drive wheel speed V1 = S, the rear drive wheel speed

[0011] When turning right, the front drive wheel speed V2=S.

[0012] A further technical solution is to send the same speed S to the front and rear drive wheels when driving in a straight line;

[0013] In front axle steering mode,

[0014] Left turn ratio calculation:

[0015] When turning left, the front drive wheel speed V1 = S, the rear drive wheel speed

[0016] Right turn ratio calculation:

[0017] When turning right, the front drive wheel speed Rear drive wheel speed V2=S.

[0018] A further technical solution is to send the same speed S to the front and rear drive wheels when driving in a straight line;

[0019] In rear axle steering mode,

[0020] Left turn ratio calculation:

[0021] When turning left, the front drive wheel speed V1 = S, and the rear drive wheel speed V2 = S × δ;

[0022] Right turn ratio calculation:

[0023] When turning right, the front drive wheel speed Rear drive wheel speed V2=S.

[0024] A further technical solution also includes a cylinder hinged on the vehicle body, a telescopic push rod is arranged in the cylinder, the push rod is hinged to the driving wheel, and the hinge point between the push rod and the driving wheel is located on the other side of the hinge point between the connecting rod and the driving wheel.

[0025] A further technical solution is that a large gear is provided on the outer surface of the driving wheel, an angle encoder is provided on the vehicle body, a small gear is provided on one side of the angle encoder, the small gear is meshed with the large gear, and the driving wheel passes through the large gear and the small gear after rotation, and the angle encoder reads the angle rotation information.

[0026] According to a further technical solution, the rotation angle of the driving wheel, angle in degrees, is calculated as follows:

[0027]

[0028] The beneficial effects of the present invention are as follows: 1. The differential control system uses an encoder and a gear set to capture the rotation angle position of the driving wheel so as to enable the vehicle to turn at a specified angle.

[0029] 2. For double-axle steering, front-axle steering and rear-axle steering, separate speeds are set for left and right turns. By utilizing the speed difference, the vehicle can be easily steered in the three steering modes, thereby improving the stability of vehicle operation.

[0030] 3. The connecting rod design of the steering mechanism is used to make the driven wheel and the driving wheel steer synchronously, which is very flexible and convenient for follow-up steering. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] For ease of explanation, the present invention is described in detail with reference to the following specific embodiments and accompanying drawings.

[0032] Figure 1 It is a schematic diagram of the overall structure of the frame of the present invention;

[0033] Figure 2 for Figure 1 Schematic diagram of the steering mechanism;

[0034] Figure 3 for Figure 2 A schematic front view of the structure of the middle driving wheel 13;

[0035] Figure 4 for Figure 1 Schematic diagram of the central steering mechanism turning left in the dual-axle steering mode;

[0036] Figure 5 for Figure 1 Schematic diagram of the central steering mechanism turning right in the dual-axle steering mode;

[0037] Figure 6 for Figure 1 Schematic diagram of the central steering mechanism turning left in front axle steering mode;

[0038] Figure 7 for Figure 1Schematic diagram of the center steering mechanism turning right in front axle steering mode;

[0039] Figure 8 for Figure 1 Schematic diagram of the central steering mechanism turning left in rear axle steering mode;

[0040] Fig. 9 for Figure 1 Schematic diagram of the center steering mechanism turning right in rear axle steering mode;

[0041] In the figure, there are a cylinder 11, a push rod 12, a driving wheel 13, a reducer motor 14, a connecting rod 15, a driven wheel 16, a large gear 21, an angle encoder 22, and a small gear 23. DETAILED DESCRIPTION

[0042] like Figure 1-Figure 9 As shown, the present invention is described in detail. For the convenience of description, the directions mentioned below are defined as follows: the up, down, left, right, front and back directions mentioned below are Figure 1 The up-down, left-right, front-back directions of the projection relationship are consistent. A double-axle steering differential control system and method of the present invention includes a frame, and two groups of steering mechanisms are arranged on the lower side of the frame. The steering mechanism includes a driving wheel 13 and a driven wheel 16 that are connected to the vehicle body for rotation. The driven wheels 16 of the two groups of steering mechanisms are arranged at the diagonal position of the vehicle body, and the driving wheel 13 is also arranged at the diagonal position of the vehicle body. A connecting rod 15 is hingedly arranged between the driven wheel 16 and the driving wheel 13. A reducer motor 14 is arranged on one side of the driving wheel 13 to drive the driving wheel 13 to rotate. Specifically, the output shaft of the reducer motor 14 is connected to the rotating wheel power in the driving wheel 13. It also includes an oil cylinder 11 hingedly arranged on the vehicle body, and a telescopic push rod 12 is arranged in the oil cylinder 11. The push rod 12 is hingedly arranged with the driving wheel 13, and the hinge point of the push rod 12 and the driving wheel 13 is located on the other side of the hinge point of the connecting rod 15 and the driving wheel 13.

[0043] Advantageously, a large gear 21 is provided on the outer surface of the driving wheel 13, an angle encoder 22 is provided on the vehicle body, a small gear 23 is provided on one side of the angle encoder 22, and the small gear 23 is meshed with the large gear 21. After the driving wheel 13 rotates, the angle encoder 22 reads the angle rotation information through the large gear 21 and the small gear 23.

[0044] Advantageously, the rotation angle of the single driving wheel 13 is angle, where angle is in degrees, calculated as follows:

[0045] The ratio of the number of teeth of the gear 21 β1 and the number of teeth of the pinion 23 β2 is calculated, that is,

[0046] but,

[0047] Advantageously, the drive wheels 13 are arranged diagonally, located at the front right and the left rear of the vehicle; when moving in a straight line, the same speed is transmitted to ensure synchronous rotation speed, so that the vehicle can move in a straight line.

[0048] Advantageously, when the vehicle turns left or right, differential calculation is required, and the calculation requires several parameters: the front driving wheel 13 angle angle1, the rear driving wheel 13 angle angle2, the front and rear wheel center distance Length, and the left and right wheel center distance Width.

[0049] Advantageously, the ratio of the front and rear drive wheel speeds can be regarded as the ratio of the distance L1 from the center of the front drive wheel to the center of rotation to the distance L2 from the center of the rear drive wheel to the center of rotation, that is,

[0050] Advantageously, during turning, it is necessary to find the ratio δ between the front drive wheel speed and the rear drive wheel speed.

[0051] Advantageously, in the dual-axle steering mode, Reference Figure 4 and 5 As shown:

[0052]

[0053] When driving in a straight line, send the same speed S to the front and rear drive wheels;

[0054] When turning left, the front drive wheel speed V1 = S, the rear drive wheel speed

[0055] When turning right, the front drive wheel speed V2=S.

[0056] Embodiment 1, advantageously, wherein, when driving in a straight line, the same speed S is sent to the front and rear drive wheels;

[0057] In front axle steering mode, Reference Figure 6 and 7 As shown;

[0058] Left turn ratio calculation:

[0059] V1=S,

[0060] Right turn ratio calculation:

[0061] V2=S.

[0062] Embodiment 2, advantageously, wherein, when driving in a straight line, the same speed S is sent to the front and rear drive wheels;

[0063] In rear axle steering mode, Reference Figure 8 and 9 As shown;

[0064] Left turn ratio calculation:

[0065] V1=S,V2=S×δ;

[0066] Right turn ratio calculation:

[0067] V2=S.

[0068] The turning function is achieved by matching different speeds when turning left and right in dual-axle drive mode, front-axle drive mode and rear-axle drive mode.

[0069] When the steering mechanism is steering, the oil cylinder 11 drives the push rod 12 to extend and retract, so that the driving wheel 13 drives the driving wheel 13 to rotate. Under the action of the connecting rod 15, the driven wheel 16 and the driving wheel 13 rotate synchronously at the same angle.

[0070] The above are only specific implementation methods of the present invention, but the protection scope of the present invention is not limited to this. Any changes or substitutions that are not conceived through creative work should be included in the protection scope of the present invention; therefore, the protection scope of the present invention should be based on the protection scope defined in the claims.

Claims

1. A differential control method for dual-axle steering, comprising a vehicle frame, two sets of steering mechanisms are arranged on the lower side of the vehicle frame, the steering mechanisms include a driving wheel (13) and a driven wheel (16) connected to the vehicle body for rotation, the driving wheels (13) are arranged diagonally and are located at the front right and left rear of the vehicle; the characteristics are: The first step is to send the same speed to the driving wheel (13) when driving in a straight line, so that the vehicle can move in a straight line; In the second step, when the vehicle turns left or right, the differential speed is calculated. The speed ratio of the front and rear drive wheels (13) can be regarded as the ratio of the distance L1 from the center of the front drive wheel to the center of rotation to the distance L2 from the center of the rear drive wheel to the center of rotation, that is, The formula calculation includes the following parameters: the front driving wheel (13) turning angle angle1, the rear driving wheel (13) turning angle angle2, the front and rear wheel center distance Length, the left and right wheel center distance Width and the ratio of the front and rear driving wheel (13) speeds. The formula matching is used to calculate the rotation speeds of the front and rear driving wheels (13) to achieve differential speed adjustment of the dual-axle steering mode, the front axle steering mode and the rear axle steering mode.

2. The differential speed control method for dual-bridge steering according to claim 1, characterized in that: In the dual-axle steering mode, find the ratio of the front drive wheel speed to the rear drive wheel speed When driving in a straight line, send the same speed S to the front and rear drive wheels; When turning left, the front drive wheel speed V1 = S, the rear drive wheel speed When turning right, the front drive wheel speed V2=S.

3. The differential speed control method for dual-bridge steering according to claim 1, characterized in that: When driving in a straight line, send the same speed S to the front and rear drive wheels; In front axle steering mode, Left turn ratio calculation: When turning left, the front drive wheel speed V1 = S, the rear drive wheel speed Right turn ratio calculation: When turning right, the front drive wheel speed Rear drive wheel speed V2=S.

4. The differential speed control method for dual-bridge steering according to claim 1, characterized in that: When driving in a straight line, send the same speed S to the front and rear drive wheels; In rear axle steering mode, Left turn ratio calculation: When turning left, the front drive wheel speed V1 = S, and the rear drive wheel speed V2 = S × δ; Right turn ratio calculation: When turning right, the front drive wheel speed Rear drive wheel speed V2=S.

5. A differential speed control method for dual-bridge steering according to any one of claims 1 to 4, characterized in that: The rotation angle angle of the driving wheel (13) is calculated as follows:

6. A system using the differential speed control method of dual-axle steering as claimed in claim 5, characterized in that: The vehicle also comprises an oil cylinder (11) hingedly arranged on the vehicle body, wherein a telescopic push rod (12) is arranged inside the oil cylinder (11), and the push rod (12) is hingedly arranged with the driving wheel (13), and the hinge point between the push rod (12) and the driving wheel (13) is located on the other side of the hinge point between the connecting rod (15) and the driving wheel (13).

7. A system for differential control method using dual-bridge steering according to claim 6, characterized in that: The outer surface of the driving wheel (13) is provided with a large gear (21), the vehicle body is provided with an angle encoder (22), one side of the angle encoder (22) is provided with a small gear (23), the small gear (23) is meshed with the large gear (21), and after the driving wheel (13) rotates, the angle encoder (22) reads the angle rotation information through the large gear (21) and the small gear (23).

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