CN108163047B

CN108163047B - Vehicle steering system and vehicle using same

Info

Publication number: CN108163047B
Application number: CN201810056608.4A
Authority: CN
Inventors: 谢辽东
Original assignee: Individual
Current assignee: Individual
Priority date: 2018-01-21
Filing date: 2018-01-21
Publication date: 2024-06-04
Anticipated expiration: 2038-01-21
Also published as: CN108163047A

Abstract

The present invention relates to a vehicle steering system and a vehicle using the same. The steering system is composed of a plurality of wheel assemblies (100, 110) and a plurality of related transmission mechanisms, and is characterized in that one wheel (5) is connected with one power source (1) and is driven to rotate by the power source (1). The steering system of the vehicle does not need a direction driving device, namely, a mechanical steering wheel or a steering rudder and a steering bridge are not needed to drive wheels or the vehicle to steer. By adjusting the rotational speed and mileage of each wheel (5), a straight forward movement and a steering movement of the vehicle can be achieved, and the vehicle can realize various movement modes, i.e., straight forward movement, ackerman steering, in-situ steering and lateral translation. And configuring a sensor for measuring the direction angle of the vehicle or the steering angle of the vehicle body according to the use scene of the vehicle, and carrying out control decision according to the acquired data.

Description

Vehicle steering system and vehicle using same

Technical Field

The invention relates to a vehicle steering system and a vehicle using the system, belongs to the field of vehicle engineering, and can also be applied to the field of robots.

Background

In a general automotive vehicle, a function of steering the vehicle controls the direction of wheels by a rudder connected to a steering axle to thereby control the steering of the vehicle. The vehicle applying the steering mode steers according to the Ackerman principle, the turning radius is larger, the vehicle cannot steer in situ, and the transverse translation of the vehicle cannot be realized.

At present, in order to realize in-situ steering, some special vehicles or robots adopt crawler-type steering or four-wheel rudder-free differential mode, and as the ground and the crawler or wheels generate relative sliding, part of movement energy is used for friction heating, the energy utilization efficiency is lower than that of the mode without relative sliding steering, the abrasion of the crawler or the wheels is increased, in-situ steering can be realized, but the transverse translation cannot be realized. The common Omni wheel or mecanum wheel chassis, although enabling both in-situ steering and lateral translation, due to the small rollers arranged at the edges of its wheels, allows it to move only on flat clean roadways and the wheels cannot go beyond obstacles above their roller radius.

For this, japanese NTN corporation produces an electric vehicle Q' mo in which an in-wheel motor is mounted on a wheel, the wheel of the vehicle is controlled by a steering device using an MDS (multi-drive system), and the wheel can be adjusted to a corresponding angle to achieve rotation and lateral translation. The patents JP 2016-132316A, JP 2015-93497A, JP 2015-44565A all propose several embodiments of such a vehicle. However, in the embodiments proposed in the above patents, steering mechanisms such as rudders and racks and motors are required to be used as driving devices for realizing steering of wheels and switching of steering modes, and the structure is complex, and the additional driving mechanisms and driving devices increase the dead weight of a vehicle body, the complexity of the mechanisms and the complexity of a control system, reduce the utilization efficiency of electric energy and require higher cost. Similarly, patent CN 101298257a also uses a similar transmission form, with the same problems as described above.

Disclosure of Invention

The invention tries to provide a vehicle steering system, which can realize the ackerman steering, and can also realize the in-situ steering and the transverse translation of the vehicle, the obstacle crossing capability is equivalent to that of the vehicle which commonly uses the ackerman steering mechanism, meanwhile, steering transmission devices such as a steering rudder, a steering axle, a differential mechanism and the like of the vehicle are omitted, and the steering of the vehicle is controlled by adopting a mode of controlling the speed and mileage of wheels, in other words, no driving devices such as a motor and the like and transmission devices such as a steering rudder, a steering axle, a differential mechanism and the like which are specially used for steering are needed no matter the ackerman steering, the in-situ steering or the transverse translation of the vehicle.

To this end, the subject of the invention is a vehicle steering system. The steering system consists of a wheel assembly and a related transmission device, wherein the wheel assembly comprises a motor, wheels and other related transmission devices, and the four wheel assemblies are hinged to the front left, rear left, front right and rear right of the frame so as to enable the four wheel assemblies to rotate along a vertical rotating shaft orthogonal to the rotating shafts of the respective wheels. Meanwhile, front and rear wheel assemblies on the same sides of the left and right sides of the vehicle body are connected by adopting a transmission device, and the wheel assemblies on the same sides of the left and right sides of the vehicle body are restrained to rotate in opposite directions only around the vertical rotating shafts, so that the movement direction of each wheel of the vehicle in the normal running process is prevented from rotating randomly.

Another subject of the invention is a vehicle using the steering system described above, which makes control decisions by means of data returned by sensors that can measure the steering angle of the vehicle or the steering angle of the vehicle body.

The invention is characterized in that the motion directions of wheels on the same side on the left side and the right side are linked and deflected through the transmission device, namely, the left front wheel and the left rear wheel can only be linked and deflected in opposite directions, the right front wheel and the right rear wheel can only be linked and deflected in opposite directions, and the deflection directions and angles of wheel assemblies are controlled through adjusting the rotating speeds and mileage of the wheels, so that three steering modes of ackerman steering, in-situ steering and transverse translation of a vehicle are realized.

Drawings

The advantages of the vehicle steering system according to the present invention will be better exhibited by describing one embodiment in detail, and the description is illustrated by the following drawings.

FIG. 1 illustrates a front view of a wheel assembly and a rotating bracket after articulation;

FIG. 2 illustrates a cross-sectional view of the wheel assembly and the rotating bracket after articulation in the direction A shown in FIG. 1;

FIG. 3 illustrates a top view of the wheel assembly after articulation with the rotating bracket;

FIG. 4 shows a top view of a vehicle in an initial state of a steering system embodying the present invention;

FIG. 5 shows a cross-sectional view of the vehicle of FIG. 4 in the direction C;

FIG. 6 shows an enlarged view of the area X in FIG. 5;

FIG. 7 is a perspective view of the vehicle of FIG. 4, and the direction of movement of the wheels as it progresses straight;

FIG. 8 illustrates the stressed state of the state shown in FIG. 7;

FIG. 9 illustrates the direction of wheel movement of the vehicle of FIG. 4 at the instant the vehicle begins to switch from an initial state to a steer-in-place mode;

FIG. 10 illustrates the stressed state of the state shown in FIG. 9;

FIG. 11 illustrates a top view of the vehicle in the in-situ steering mode of FIG. 4;

FIG. 12 illustrates a top view of the vehicle lateral translation mode illustrated in FIG. 4;

FIG. 13 illustrates a top view of the ackerman steering mode of the vehicle illustrated in FIG. 4;

FIG. 14 illustrates another vehicle evolved from the vehicle of FIG. 4;

The same parts or components in the above figures are shown with the same reference numerals, and individuals who may have multiple identical parts or components in the same vehicle, different individuals of which are distinguished by "-numerals", for example, two different individuals of the wheel assembly 100 are shown with 100-1 and 100-2, respectively; features describing the geometric relationship of the parts or assemblies, such as geometric abstractions of axes of rotation, planes of symmetry, etc., are also distinguished by "-numerals" in different individuals, e.g., the axes of rotation 002 of the center wheel 5 of different individuals of the wheel assembly 100 are shown with 002-1 and 002-2, respectively.

Detailed Description

Fig. 1,2 and 3 show an embodiment of a steering system for a vehicle according to the present invention, in which a wheel assembly 100 and a rotating bracket 21 are hinged, and the wheel assembly 100 is composed of a power source 1, an angle sensor 2, a direction transmission member 3, a power source bracket 4, wheels 5, an upper horizontal support 6, a wheel support 7, a lower horizontal support 8 and a wheel fixing 9; the power source support 4 is rigidly connected with the power source 1 and the direction transmission part 3, and is hinged to the rotating support 21 through the upper horizontal support 6 and the lower horizontal support 8, and the power source 1 is connected with the wheel fixing 9 and the wheel 5 through the wheel support 7 to drive the wheel to rotate. In this embodiment of the vehicle steering system, the wheel assemblies 110 and 100 are identical in construction and are articulated with the rotating bracket 22 in the same manner as described above.

Fig. 4 shows an embodiment of a steering system for a vehicle according to the invention, which vehicle is formed by a frame 200, two sets of wheel assemblies 100, 110, two sets of transmission members 101, 111, two sets of second transmission wheels 102, 112, two sets of transmission shafts 103, 113, two sets of support assemblies 104, 114, two sets of interlocking wheels 105, 115, and two interlocking supports 201; the vehicle is divided into four regions by plane 003 and plane 004, namely, a left front region, a left rear region, a right front region, and a right rear region, wherein the wheel assemblies 100-1, 100-2 are hinged to the right front region and the left rear region of the vehicle by the rotating brackets 21-1, 21-2, and the wheel assemblies 110-1, 110-2 are hinged to the right rear region and the left front region of the vehicle by the rotating brackets 22-1, 22-2.

Fig. 5 shows a cross-sectional view of the vehicle steering system of fig. 4 in the direction C, and fig. 6 shows an enlarged view of the region X of fig. 5, detailing the details of the linkage between the wheel assemblies 100, 110; the direction driving parts 3 of the wheel assemblies 100 and 110 are respectively connected with the second driving wheels 102 and 112 through driving parts 101 and 111, and the second driving wheels 102 and 112 are respectively and rigidly connected with the transmission shafts 103 and 113 and the interlocking wheels 105 and 115; the drive shafts 103, 113 are hinged to the interlocking support 201 by support assemblies 104, 114, respectively.

Wherein the interlocking wheels 105 and 115 interact to rotate only in opposite directions, and the wheel assemblies 100 and 110 on the same side on the left and right sides of the plane 003 are deflected only in opposite directions and cannot be deflected in the same direction by the above-described transmission mechanism.

In the above example of the invention, the interlocking wheels 105 and 115 are preferably realized in the form of gears, the interaction of which is the meshing force of the two gears with each other, so that they can only rotate in opposite directions; however, in the steering system of the vehicle according to the present patent, other implementations of the interlocking wheels may be used, such as ball screws, worm gears, synchromesh pulley trains, friction wheels, linkages, cam structures, hydraulic mechanisms, pneumatic mechanisms, and any other mechanical transmission mechanism that may produce a rotational restraint effect in the opposite direction.

In the above-described example of the invention, the transmission members 101 and 111 are preferably realized in the form of synchronous belts, and the respective second transmission wheels 102, 112 and the direction transmission member 3 are realized in the form of synchronous pulleys; however, in the vehicle steering system according to the present patent, the form of the synchronous belt and the synchronous pulley may be implemented by other transmission modes, such as a transmission rod and a gear, a multi-gear set, a rack and a gear, a chain and a sprocket, a friction belt and a friction pulley, or any other mechanical connection mechanism that may produce the same transmission effect as described in the present patent.

In the above example of the invention, the power source 1 is preferably implemented in the form of an electric motor, which may be directly connected to the wheels or may be connected via a transmission mechanism having a certain speed reducing function, or may be implemented in any other power output device.

In the above example of the present invention, the implementation form of the rigid connection structure of the power source 1, the wheel support 7, and the wheel fixing 9 may be replaced with an in-wheel motor.

In the above example of the invention, the upper horizontal support 6 and the lower horizontal support 8 are preferably implemented as deep groove ball bearings and thrust ball bearings, respectively, but any other support that can withstand radial and axial forces may be used.

In the above example of the present invention, the speed sensor for measuring the rotation speed of the wheel 5 is preferably a photoelectric encoder of the motor, or any sensor capable of measuring the rotation speed, such as a hall sensor, a magnetic induction sensor, etc., and calculates the mileage of the wheel by integrating the speed with respect to time.

In the above-described examples of the present invention, preferably, all the angle sensors 2 that measure the yaw angle of the wheel assemblies 100, 110 about the axes 001, 011, respectively, are implemented using potentiometers, but any sensor that can measure relative rotational angles, such as absolute value encoders, etc., may be used.

The state depicted in fig. 4 is an initial state of the vehicle, in which the direction indicated by the arrow at the center of the upper side of fig. 4 is taken as the direction of straight forward travel, and in this state, the axes 002-1, 002-2, 012-1, 012-2 are all orthogonal to the neutral plane 003, and the positions of the wheel assemblies 100-1, 100-2, 110-1, 110-2 are 0 ° positions, that is, the direction angle data fed back by the respective angle sensors 2 are 0 °, and the signs of the deflection angles of the wheel assemblies 100-1, 100-2, 110-1, 110-2 around 001-1, 001-2, 011-1, 011-2 are respectively taken as positive directions and the clockwise directions are taken as negative directions.

When the vehicle is traveling straight in the forward direction on the ground, the wheel 5 in the wheel assembly 100-1 rotates in the direction CC1 shown in fig. 1, and the wheel 5 receives frictional force from the ground, thereby generating a turning moment in the direction CCW2 shown in fig. 3 to act on the wheel assembly 100-1. Extending to all of the wheel assemblies 100-1, 100-2, 110-1 and 110-2, the direction of wheel rotation is shown in fig. 7, the direction of force is shown in fig. 8, the straight arrow at the upper center in the drawing represents the direction of movement of the vehicle, the straight arrow beside all of the wheels representatively faces the direction of the friction force of the corresponding wheel, and the curved arrow beside each straight arrow represents the direction of torque generated by the friction force on the corresponding wheel assembly at the axes 001-1, 001-2, 011-1, 011-2, respectively. From analysis, if the transmission 101-1, 101-2, 111-1, 111-2 were not present, then at vehicle start-up, the vehicle would not be able to advance because the wheel assemblies 100-1, 100-2, 110-1, 110-2 would be free to rotate about 001-1, 001-2, 011-1, 011-2, respectively, and upon receipt of such moments, all wheel assemblies would deflect in the corresponding moment directions, and the axes of rotation 002-1, 002-2, 012-1, 012-2 of all wheels would no longer be parallel.

According to the implementation and connection modes of the various components mentioned in the above examples of the present invention, the wheel assemblies 100, 110 on the same sides of the neutral plane 003 are respectively connected with the gears meshed with each other by using the synchronous belt and the synchronous pulley as well as the transmission shaft; as known from the mechanical principle, when two gears are engaged and assembled, the two gears cannot rotate in the same direction; obviously, at any time after the start of the vehicle, if the rotational speeds of the wheels on the same side on both sides of the neutral plane 003 are equal, the mileage is also equal, and if the slipping phenomenon of the wheels and the ground does not occur, the moment of the curved arrow in fig. 8, which is applied to each wheel assembly 100, 110, will be offset by the moment generated by the meshing force of the gears and transmitted to the axis 001,011 by the synchronous belt, the wheel assemblies 100, 110 will not deflect, and the vehicle will maintain the straight-line forward motion state.

Fig. 9 and 10 show the wheel movement direction and the force direction, respectively, at the moment when the switch from the initial state to the in-situ steering mode is started. As can be seen from the figure, in the switching process, if the rotation speeds of the wheels on the same side on both sides of the neutral plane 003 are equal, the mileage is equal, but the directions are opposite, the gears meshed with each other are driven to rotate in opposite directions by the transmission mechanism such as the synchronous belt, and no meshing force is generated between the gears. When each wheel assembly is deflected to the position shown in fig. 11, i.e., the rotational axes 002-1, 002-2, 012-1, 012-2 of each wheel intersect at a point Z, all the wheels stop rotating and the mode switching is completed. In this mode, all wheels rotate in the same direction to achieve in-situ steering of the whole vehicle clockwise or anticlockwise. To return to the initial state shown in fig. 4, all wheels may be rotated in the direction opposite to the arrow direction shown in fig. 9.

In fig. 11, if the deflection angles of the axes 002-1, 002-2, 012-1, 012-2 with the wheel assemblies 100-1, 100-2, 110-1, and 110-2, respectively, are a1, b2, a2, b1, respectively, then a1=b2=45°, a2=b1= -45 ° in this example, according to the symbol rule of the present invention, as described above.

Fig. 12 shows a vehicle form of a lateral translational mode, in which the mode switching from the initial state to this mode is the same as the switching to the in-situ steering mode, and the mode switching can be completed only by moving all the wheels to a position where 002-1 coincides with 012-1 and 002-2 coincides with 012-2, that is, a position where a1=b2=90°, a2=b1= -90 °, and the wheel control manner in the lateral translational mode is the same as the control manner of the straight line traveling. In particular, when the vehicle is operated in this mode, i.e., translated laterally sideways, it is necessary to provide damping that resists yaw movement of the wheel assemblies about the axes 001-1, 001-2, 011-1, 011-2, preventing each wheel assembly from yaw in a direction that reduces the absolute value of a1, b2, a2, b 1.

Fig. 13 shows a state in which the vehicle is in the ackerman steering mode, and this figure exemplifies a right turn. Unlike the two steering modes described above, the two steering modes can be switched only to each other or to the initial state when the linear velocity of movement of the frame 200 is zero. The ackerman steering mode may be switched from the vehicle straight-ahead state. According to the ackerman steering principle, the vehicle steering center T is located at the intersection of the rotational axes 002-1, 002-2, 012-1, 012-2 of all the wheels. To switch to this mode, the mileage of each wheel 5 needs to be controlled, and assuming that the respective mileage of 100-1, 100-2, 110-1 and 110-2 are P1, P2, P3 and P4, respectively, the mileage of the wheel needs to be controlled to make the following equation hold:

P1-P3=2*PI*R2*(|a1|+|a2|)/360

P4-P2=2*PI*R1*(|b1|+|b2|)/360

Wherein PI represents the circumference ratio.

The vehicle steering system related to the invention can be evolved into a second vehicle steering system, as shown in fig. 14, at least one group of transmission members 101, 111, second transmission wheels 102, 112, transmission shafts 103, 113, support assemblies 104, 114, interlocking wheels 105, 115 and an interlocking support 201 are added on the basis of the vehicle steering system shown in fig. 4; the wheel assemblies 100-1 and 110-2 are additionally connected in the same manner as the first vehicle steering system; or a group of transmission parts 101, 111, second transmission wheels 102, 112, transmission shafts 103, 113, support assemblies 104, 114, interlocking wheels 105, 115 and an interlocking support 201 are additionally arranged; the same manner of connection as the first vehicle steering system additionally connects the wheel assemblies 100-2 and 110-1; the added transmission mechanism can prevent each wheel assembly from deflecting along the direction of reducing the absolute value of a1, b2, a2 and b1 in the transverse translation mode, namely the damping can be replaced, but the steering system added with the connection mode does not have the Ackerman steering mode any more.

The first vehicle steering system according to the present invention can be developed into a third vehicle steering system having three or more sets of wheel assemblies 100, 110, wherein all the wheel assemblies are disposed on both sides of a neutral plane on average, the yaw motions of all the wheel assemblies on the same side are linked, and the rotation axes of all the wheels can intersect at one point after some or all of the wheel assemblies are deflected.

In the vehicle adopting the steering system, at least one sensor such as a gyroscope, a geomagnetic sensor, a GPS antenna and the like which can measure the direction angle of the vehicle or the rotation angle of the vehicle body is used for feeding back the vehicle posture data in the vehicle control process, so that a driver of the vehicle or an automatic driving system can be ensured to obtain the real motion data of the vehicle, and a correct driving decision is made.

All vehicle steering systems evolved on the basis of the first, second and third vehicle steering systems according to the present invention and vehicles using such systems are within the scope of the present patent description.

Claims

1. A vehicle steering system constituted by a frame (200), wheel assemblies (100, 110), transmission members (101, 111), transmission wheels (102, 112), transmission shafts (103, 113), support assemblies (104, 114), interlocking wheels (105, 115), and an interlocking support (201), characterized in that: the wheel assemblies (100, 110) are respectively hinged on rotating brackets (21, 22) fixed on a frame (200), namely the wheel assemblies (100, 110) can not rotate along the same direction at any moment, the wheel assemblies (100, 110) on the same side of a neutral plane (003) are respectively connected with driving wheels (102, 112) through driving parts (101, 111), the driving wheels (102, 112) are respectively and rigidly connected with driving shafts (103, 113), the driving shafts (103, 113) are respectively and rigidly connected with interlocking wheels (105, 115), and are respectively hinged on the interlocking support (201) through supporting assemblies (104, 114), the interlocking wheels (105, 115) on the same side of the neutral plane (003) can not rotate along the same direction at any moment, so that the corresponding wheel assemblies (100, 110) can not deflect along the same direction respectively, the deflection angles of all the wheel assemblies (100, 110) around the axes (001, 011) are respectively measured by taking the position of all the axes (002, 012) which are orthogonal to the neutral plane (003) as an initial position, namely, a state of 0 degree, and a clockwise rotation range of the wheel assemblies is increased to a clockwise rotation range of the wheel assemblies (85 degrees, namely a clockwise rotation range of the wheel assemblies is increased to a clockwise rotation range of the damper device is in which is a clockwise rotation range of 90 degrees, the addition of the same damping means causes the wheel assembly (110) to have damping forces within the range of-85 deg. to-90 deg. of deflection that resist its deflection.

2. The vehicle steering system of claim 1, wherein: different tires are adopted on the wheels (5) according to different road conditions, so that the moment which can be generated by the maximum static friction force of the tires and the ground on the axes (001, 011) is larger than the moment which is generated by the damping force on the same position.

3. The vehicle steering system according to any one of claims 1-2, characterized in that: all wheel assemblies (100, 110) are equipped with angle sensors (2) measuring their deflection about axes (001, 011), respectively.

4. The vehicle steering system according to any one of claims 1-2, characterized in that: all wheels (5) are equipped with speed sensors that can measure their rotational speed, for feeding back the rotational speed of the wheels (5) and by calculation their mileage.

5. A vehicle, characterized in that: the steering system according to any one of claims 1 to 4, wherein the frame (200) is provided with at least one sensor for measuring a steering angle of the vehicle or a steering angle of the vehicle body, such as a gyroscope, a geomagnetic sensor, and a GPS antenna.