KR20140119587A - Vehicle - Google Patents

Abstract

The present invention discloses a vehicle. The present invention includes: a plurality of in-wheel motors which are installed in each of a plurality of wheels; a sensor unit for measuring the inclination of a vehicle body; and a control unit for controlling each of the in-wheel motors in order to apply an initial torque corresponding to the vertical force of each wheel which is initially set, and for varying the initial torque on the basis of the calculated vertical force of each wheel after calculating the vertical force of each wheel based on the inclination.

Description

Vehicle {Vehicle}

The present invention relates to a vehicle.

The vehicle can generally include a wheel that is rotatably mounted to the vehicle body. Further, the vehicle may include a steering wheel for inputting the steering angle of the wheel, and a steering unit for controlling the steering angle of each wheel in accordance with the signal inputted from the steering wheel. In particular, the vehicle may include a wheel drive unit connected to each wheel or installed on each wheel to move each wheel. At this time, various forms can be manufactured according to the purpose of the vehicle. For example, a wheel drive unit may be installed in each wheel individually or in combination with a plurality of wheels to drive a plurality of wheels simultaneously.

On the other hand, in the case where the wheel drive units are individually provided in the above-described vehicles, an in-wheel motor is generally installed in each wheel. A vehicle equipped with such an in-wheel motor should support the output of the wheel in a robot or a future military vehicle in a variable manner according to the driving purpose and the situation. However, in the case of a vehicle equipped with a wheel drive unit that simultaneously drives a plurality of wheels as described above, there is a limit in distributing the output of the engine through the gear to vary the drive output for each wheel with respect to the running situation. Therefore, in order to vary the driving output for each wheel as described above, a vehicle using an in-wheel motor should be used. Particularly, in the case of a vehicle using an in-wheel motor as described above, it is disclosed in Korean Patent Laid-Open Publication No. 2013-0012827 (entitled "Control Apparatus and Method of In-Wheel System Vehicle, Applicant: Hyundai Motor Co., Ltd.)".

Korean Patent Laid-Open Publication No. 2013-0012827

Embodiments of the present invention are intended to provide a vehicle that is capable of stable running according to the ground conditions.

According to an aspect of the present invention, there is provided an in-wheel motor comprising a plurality of in-wheel motors provided on each of a plurality of wheels, a sensor unit for measuring a degree of inclination of the vehicle body, And a control unit for controlling the motor and calculating the normal force of each wheel based on the inclination and varying the initial torque based on the calculated normal force of each wheel.

Further, if it is determined that the inclination is out of the inclination range, the in-wheel motor that varies the in-wheel motor torque of each of the wheels based on the calculated normal force of the respective wheels can be controlled.

The sensor unit measures a vehicle speed and a rotation speed of each of the wheels, and the control unit calculates a slip ratio of each of the wheels based on the vehicle speed and the rotation speed of each of the wheels. Based on the slip ratio, The vertical force of the wheel can be varied.

In addition, if it is determined that the slip rate of each wheel is equal to or greater than a first predetermined slip rate, the control unit may increase the vertical force of the remaining wheels except the smallest wheel among the wheels.

If it is determined that the slip rate of each wheel exceeds the predetermined second set slip rate, the control unit may decrease the in-wheel motor torque of the wheel in which the slip rate exceeds the second set slip rate The in-wheel motor can be controlled.

In addition, the vertical force of each of the wheels according to the inclination can be preset and stored in the controller.

Embodiments of the present invention can reduce the energy used in the vehicle by controlling the individual torque formed in each in-wheel motor according to the inclination of the vehicle and the slip ratio of each wheel. Further, the embodiments of the present invention can ensure the stability of the vehicle operation by controlling the individual torque of the in-wheel motor according to the environment, and can provide the running performance optimized for the external environment.

1 is a conceptual diagram showing a vehicle according to an embodiment of the present invention.
2 is a block diagram showing the control flow of the vehicle shown in Fig.
3 is a flowchart showing a control procedure of the vehicle shown in Fig.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which: FIG. The present invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Is provided to fully convey the scope of the invention to those skilled in the art, and the invention is only defined by the scope of the claims. It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. In the present specification, the singular form includes plural forms unless otherwise specified in the specification. It is noted that the terms "comprises" and / or "comprising" used in the specification are intended to be inclusive in a manner similar to the components, steps, operations, and / Or additions. The terms first, second, etc. may be used to describe various elements, but the elements should not be limited by terms. Terms are used only for the purpose of distinguishing one component from another.

1 is a conceptual diagram showing a vehicle 100 according to an embodiment of the present invention. 2 is a block diagram showing the control flow of the vehicle 100 shown in Fig. 3 is a flowchart showing a control procedure of the vehicle 100 shown in Fig.

1 to 3, the vehicle 100 may include a vehicle body (not shown). The vehicle 100 may include a plurality of wheels (not shown) rotatably mounted on the vehicle body. At this time, the number of the plurality of wheels may be variously formed. For example, the number of the plurality of wheels may be four, six, eight, or the like. Hereinafter, for convenience of explanation, the case where the number of the plurality of wheels is six will be described in detail. The plurality of wheels will be described in detail with respect to a case where a pair of wheels are arranged on the front wheel, a pair is arranged on the middle wheel, and a pair is arranged on the rear wheel.

The plurality of wheels may include a pair of first wheels 111 disposed on the front wheels, a pair of second wheels 112 disposed on the middle wheels, and a pair of third wheels 113 disposed on the rear wheels. have.

On the other hand, the vehicle 100 may include an in-wheel motor (not shown) installed on each wheel. At this time, a plurality of in-wheel motors 120 may be provided, and the in-wheel motors 120 may be individually installed in the respective wheels. In particular, the plurality of in-wheel motor 120 includes a first in-wheel motor 121 installed on each of the pair of first wheels 111, a second in-wheel motor 122 installed on each of the pair of second wheels 112, And a third in-wheel motor 123 installed on each of the third wheels 113 of the first wheel.

 In addition, the vehicle 100 may include a sensor unit 130 for measuring the inclination of the vehicle body. At this time, the sensor unit 130 can measure the vehicle speed and the rotational speed of each wheel in addition to the inclination of the vehicle body.

Particularly, the sensor unit 130 includes a tilt detection sensor unit 134 for measuring the tilt of the vehicle body, a vehicle speed sensor unit 135 for measuring the vehicle speed of the vehicle body, and a wheel rotation speed sensor unit 135 for measuring the rotation speed of each wheel. (Not shown). At this time, a plurality of the wheel rotation speed detection sensor units may be provided. Specifically, the plurality of wheel rotational speed detecting sensors include a first wheel rotational speed detecting sensor unit 131 installed on each of the pair of first wheels 111, a second wheel rotational speed sensor unit 131 disposed on each of the pair of second wheels 112, And a third wheel rotational speed sensor unit 133 disposed on each of the rotational speed sensor unit 132 and the pair of third wheels 113.

Meanwhile, the vehicle 100 may include a control unit 190 for controlling the torque of each in-wheel motor 120. At this time, the control unit 190 may control each in-wheel motor 120 to apply the initial torque corresponding to the initial set vertical force of each wheel. In addition, the control unit 190 can vary the initial torque applied to each in-wheel motor 120 based on the calculated normal force of each wheel after calculating the normal force of each wheel based on the inclination of the vehicle body.

The control unit 190 may include a traveling control unit 191 that collectively controls the traveling of the vehicle 100. The control unit 190 may include an in-wheel motor control unit 193 electrically connected to the running control unit 191 and electrically connected to the in-wheel motor 120 to control the in-wheel motor 120.

The vehicle 100 may include an acceleration pedal 140 that receives a booty speed signal externally. At this time, since the acceleration pedal 140 is the same as or similar to the acceleration pedal of the general vehicle 100, detailed description thereof will be omitted.

Meanwhile, the driving method of the vehicle 100 will be described. First, the speed signal can be inputted from the acceleration pedal 140. When the speed signal is input as described above, the speed signal may be applied to the travel controller 191. At this time, the travel control unit 191 may control the respective in-wheel motor 120 to generate an initial torque corresponding to the predetermined normal force of the respective wheels (S110)

Specifically, the first initial vertical force of the first wheel 111 to the third initial vertical force of the third wheel 113 may be preset in the travel control unit 191. That is, the running control unit 191 receives the first initial vertical force, the second initial vertical force, and the third initial initial force, which are the initial vertical forces applied to the first wheel 111 to the third wheel 113 proportional to the weight of the vehicle 100, It can be set to a normal force. At this time, the first initial vertical force to the third initial vertical force may be determined based on the speed signal input from the acceleration pedal 140.

On the other hand, the driving control unit 191 calculates the first initial vertical force to the third initial vertical force by calculating the total driving force required for the vehicle 100 based on the current speed and the speed signal input from the acceleration pedal 140 .

At this time, the travel control unit 191 can calculate the individual torque required for each in-wheel motor 120 based on the total driving force. Specifically, the individual torque required for each in-wheel motor 120 can be calculated by the following equation (1).

T: Individual torque of each in-wheel motor

F: Total driving force required to drive the vehicle

N: total number of wheels (N is a natural number)

S: Vertical force acting on each wheel

As described above, the individual torque required for each in-wheel motor 120 calculated by the travel control unit 191 is determined by the first initial torque of the first in-wheel motor 121, the second initial torque of the second in- And can be the third initial torque. At this time, generally, the first to third initial torques may be uniformly formed, but they may be set different from each other according to the first initial normal force to the third initial normal force. In general, the first initial normal force to the third initial normal force may be the largest in the front wheel, the second wheel in the rear wheel, and the smallest in the middle wheel. In particular, the first initial vertical force may be set to be the largest, the third initial vertical force may be the second, and the second initial vertical force may be set to the smallest.

In addition, the vertical force formed on each wheel including the first initial vertical force to the third initial vertical force may be proportional to the weight of the vehicle 100 applied to each wheel. In particular, the weight of the vehicle 100 applied to each wheel may be set to a weight ratio corresponding to the weight of the vehicle 100 applied to each wheel. In addition, the vehicle 100 applied to each wheel may be initially set in the travel control unit 191, and may be calculated again in accordance with the vehicle speed and the inclination at the time of driving the vehicle.

When the first to third initial torques are set as described above, the travel control unit 191 applies a signal to the in-wheel motor control unit 193, and the in-wheel motor control unit 193 controls the in- The first to third in-wheel motors 121 to 123 can be controlled so that the first to third initial torque to the third in-line motor 121 to the third in-wheel motor 123 are formed.

When the above process is completed, the travel controller 191 continuously monitors whether the speed signal is applied from the acceleration pedal 140, and repeats the above process when the speed signal is input.

Meanwhile, when the vehicle 100 travels as described above, the inclination sensor unit 134 may measure the inclination of the vehicle 100. [ At this time, the inclination of the vehicle 100 measured by the inclination detection sensor unit 134 may be transmitted to the travel control unit 191. In operation S120,

When the inclination of the vehicle 100 is input as described above, the travel control unit 191 can determine whether the inclination of the vehicle 100 is out of the preset inclination range. (Steps S131 and S141) At this time, The traveling control unit 191 can maintain the above-described condition (step S144)

On the other hand, if it is determined that the inclination of the vehicle 100 is out of the preset inclination range, the driving control unit 191 can determine whether the inclination of the vehicle 100 is less than the first set inclination, which is the lowest value among the preset inclination ranges . At this time, the travel control unit 191 can determine that the vehicle 100 is inclined down or stopped rapidly (step S131)

On the other hand, if it is determined that the vehicle 100 is operating as described above, the travel control unit 191 may determine whether the slip occurs in each of the wheels. Specifically, the first wheel rotational speed sensor 131 to the third wheel rotational speed sensor 133 may sense the rotation of the respective wheels and transmit them to the travel controller 191. The vehicle speed sensor 135 may sense the vehicle speed of the vehicle 100 and may transmit the sensed vehicle speed to the travel control unit 191.

The driving control unit 191 may calculate the wetting ratios of the respective wheels based on the rotational speeds of the respective wheels and the vehicle speed of the vehicle 100. [ At this time, the wetting ratios of the respective wheels may differ depending on the degree of inclination.

Specifically, when the inclination of the vehicle 100 is lowered because the inclination of the vehicle 100 is less than the preset first inclination, or when the vehicle 100 decelerates, the wetting rate of each wheel when the vehicle 100 is braking Can be calculated from the following equation (2).

Where R = individual wheel slip rate, Vc = vehicle speed, and Vw = individual wheel speed.

When the slip rate of each wheel is calculated as described above, the travel control unit 191 can determine whether the slip rate of each wheel exceeds a predetermined first set slip rate (step S132)

At this time, if it is determined that the slip ratio of each wheel is less than the predetermined first set slip ratio, the travel control unit 191 calculates again the vertical force of each wheel based on the inclination of the vehicle 100 can do. At this time, the vertical force of each wheel can be calculated from the weight or the weight ratio of each wheel. Hereinafter, for the sake of convenience of explanation, the case where the calculation is performed by the weight ratio will be described in detail.

Specifically, the weights of the vehicle 100 to be distributed to the first wheel 111 to the third wheel 113 when the inclination of the vehicle 100 is within a predetermined inclination range are denoted by M1, M2, and M3, respectively, Assuming that the weights of the vehicle 100 to be distributed to the first wheel 111 to the third wheel 113 when the inclination of the vehicle 100 is less than the first set inclination are M1 ', M2' and M3 ', respectively . At this time, the weight ratio can be formed to be M1: M2: M3 = a: b: c, and a + b + c = 1. Where a, b, c may all be a predetermined constant of 1 or less. Further, M1 ', M2', and M3 'can be calculated through the following equation (3).

Here, the values of a, b, and c may be used for M1, M2, and M3, respectively. When the weight of the vehicle 100 applied to each wheel is calculated, based on the calculated weights M1 ', M2', and M3 ' The weight ratios distributed to the first wheel 111 to the third wheel 113 are as follows: first wheel 111: second wheel 112: third wheel 113 = a1: b1: c1 = M3 ': M2' : M1 '. Here, a1, b1, and c1 may be all the calculated constants of 1 or less, and a1 + b1 + c1 = 1.

At this time, the first vertical force of the first wheel 111 to the third vertical force of the third wheel 113 may be stored in a tabular form according to the weight ratio. In particular, the first vertical force to the third vertical force may be set to be subdivided according to the speed signal input from the acceleration pedal 140. In operation S133,

When the above process is completed, the travel control unit 191 can calculate the individual torque required for each wheel through Equation (1). At this time, the individual torque required for each wheel may vary from the first initial torque to the third initial torque. In particular, the individual torque required for each in-wheel motor 120 can be calculated in accordance with the first normal force to the third normal force calculated above.

When the individual torque required for each in-wheel motor 120 is calculated as described above, the running control unit 191 can send a signal related to the individual torque required for each in-wheel motor 120 to the in-wheel motor control unit 193. At this time, the in-wheel motor control unit 193 can vary the torques of the first in-wheel motor 121 to the third in-wheel motor 123 based on the transmitted signal. In particular, the in-wheel motor control unit 193 may vary the first initial torque of the first in-wheel motor 121 to the third initial torque of the third in-wheel motor 123.

On the other hand, if it is determined that the slip ratio of each wheel is equal to or greater than the predetermined first set slip rate, the vertical force of the remaining wheels except the wheel having the smallest vertical force can be increased. Specifically, the travel control unit 191 can calculate M2 'and M3' in the following equation (4).

Here,? And? Are constants that can be selectively used for tuning the slip rate of each wheel. At this time, it is generally possible to satisfy α <β. Further,? And? Can be used to calculate the normal force of each wheel when the slip occurs in each of the wheels.

When the weight of the vehicle 100 applied to each wheel is calculated, the calculated weights M1 ', M2', and M3 'are calculated based on the values of a, b, Second wheel: third wheel = a2: b2: c2 = M3 ': M2': M1 'to be distributed to the first wheel 111 to the third wheel 113 by the first wheel . Here, a2, b2, c2 may all be a calculated constant of 1 or less, and a2 + b2 + c2 = 1 (step S134)

When the vertical force of the first wheel 111 and the second wheel 112 is calculated as described above, the normal force of the first wheel 111 and the second wheel 112 becomes larger than that of the first wheel 111 and the vertical force of the third wheel 113 Can be maintained. Therefore, when decelerating, the vertical force is more distributed to the front wheel side of the vehicle 100, that is, the first wheel 111 and the second wheel 112, and the third wheel 113, So that it is possible to prevent a slip from occurring in each of the wheels.

Meanwhile, when the vertical force is redistributed to each wheel as described above, each of the wheel rotational speed detecting sensor units may continuously feedback the speed of each of the wheels to the travel control unit 191. At this time, the travel control unit 191 can continuously calculate the slip ratios of the respective wheels through the speeds of the respective wheels fed back from the wheel rotational speed detection sensor units.

In particular, the travel control unit 191 can determine whether the calculated slip rate of each of the wheels exceeds a predetermined second set slip rate (S135). At this time, the travel control unit 191 determines whether or not the slip rate The in-wheel motor control unit 193 can be controlled so as to reduce the torque of the corresponding in-wheel motor 120 when it is determined that the predetermined second set slip rate is exceeded. For example, when it is determined that the slip ratio of the first wheel 111 exceeds the predetermined second set slip ratio, the travel control unit 191 controls the torque of the first in-wheel motor 121 to be smaller than that of the first in- The first in-wheel motor 121 can be controlled through the control unit 193 (step S137)

On the other hand, when the slip rate of each wheel does not exceed the second set slip rate, the travel control unit 191 calculates the slip rate corresponding to the vertical force of each of the wheels calculated in the above-described [Expression 3] or [Expression 4] The in-wheel motor control unit 193 can be controlled to maintain the torque of each formed in-wheel motor 120 (step S136)

In addition to the above case, the case where the vehicle 100 is sloping up or accelerating rapidly may be performed in a manner opposite to that described above.

Specifically, the travel control unit 191 can determine whether the inclination of the vehicle 100 exceeds a second predetermined inclination, which is the maximum value of the predetermined inclination (Step S141). At this time, If the set inclination is not exceeded, the current state can be maintained as it is (step S144)

On the other hand, if the slope of the vehicle 100 exceeds the second set slope, the travel control unit 191 can determine whether the slip rate of each wheel exceeds a predetermined first set slip rate. )

In order to calculate the slip rate of each wheel, the travel control unit 191 detects the speed of each wheel through the first wheel speed sensor unit 131 to the third wheel speed sensor unit 133 can do. At this time, the travel control unit 191 can calculate the slip ratio of each wheel based on the speed of each of the wheels and the vehicle speed of the vehicle 100. Specifically, the running control unit 191 can calculate the slip ratio of each wheel through the following equation (5).

Where R = individual wheel slip rate, Vc = vehicle speed, and Vw = individual wheel speed.

If it is determined that the slip rate of each wheel does not exceed the first set slip rate, the travel control unit 191 calculates the weight ratio of each wheel through Equation (3) The vertical force of the wheel can be calculated. In particular, the weight ratios to be distributed to the first wheel 111 to the third wheel 113 respectively are: first wheel: second wheel: third wheel = a3: b3: c3 = M1 ' '. Here, a3, b3, and c3 may be all the calculated constants of 1 or less, and a3 + b3 + c3 = 1 (step S143)

When the weight to be distributed to the first wheel 111 to the third wheel 113 is calculated as described above, the travel control unit 191 calculates the weight of the first in-wheel motor 121 through the third in-wheel motor 121 through Equation (1) The individual torque of the third in-wheel motor 123 can be calculated.

The individual torque calculated as described above is transmitted to the in-wheel motor control unit 193 from the travel control unit 191 and the in-wheel motor control unit 193 can control each in-wheel motor 120 to suit the individual torque.

If it is determined that the slip rate of each wheel exceeds the first set slip rate, the travel control unit 191 calculates a weight ratio to be distributed to the first wheel 111 to the third wheel 113 by Equation 4 (Step S145). In particular, the weight ratios distributed to the first wheel 111 to the third wheel 113 in the above-mentioned case are respectively calculated by the first wheel 111 and the second wheel 113, Second wheel: third wheel = a4: b4: c4 = M1 ': M2': M3 '. Here, a4, b4, and c4 may be all the calculated constants of 1 or less, and a4 + b4 + c4 = 1 (step S145)

When the calculation of the weight ratios to be distributed to the first wheel 111 to the third wheel 113 is completed as described above, the travel control unit 191 calculates the weight ratios to be distributed to the first in-wheel motor 121 through the above- To the third in-wheel motor 123, respectively. At this time, the travel control unit 191 can control the in-wheel motor control unit 193 so that individual torque is applied to each in-wheel motor 120.

Meanwhile, during the above process, the driving control unit 191 can continuously receive the feedback of the slip ratio of each wheel as described above. At this time, the driving control unit 191 can determine whether at least one of the slip ratios of the respective wheels exceeds a second set slip ratio (S146). At this time, at least one of the slip ratios of the respective wheels The in-wheel motor control unit 193 may be controlled to reduce the in-wheel motor 120 torque within the corresponding wheel when the set slip rate is exceeded (step S148)

On the other hand, when at least one of the slip ratios of the wheels is equal to or less than the second set slip ratio, the travel control unit 191 may control the in-wheel motor control unit 193 to maintain the torque of the in- have.

Therefore, the vehicle 100 can reduce the energy used in the vehicle 100 by controlling the individual torques formed in the respective in-wheel motor 120 according to the inclination of the vehicle 100 and the slip ratio of the respective wheels. In addition, the vehicle 100 can secure the driving stability of the vehicle 100 by controlling the individual torque of the in-wheel motor 120 according to the environment, and can provide the driving performance optimized for the external environment.

Although the present invention has been described in connection with the above-mentioned preferred embodiments, it is possible to make various modifications and variations without departing from the spirit and scope of the invention. Accordingly, it is intended that the appended claims cover all such modifications and variations as fall within the true spirit of the invention.

100: vehicle
111: first wheel
112: second wheel
113: Third wheel
120: In-wheel motor
121: first in-wheel motor
122: 2nd in-wheel motor
123: Third In-wheel Motor
130:
131: First wheel rotation speed detection sensor unit
132: second wheel rotational speed detecting sensor unit
133: Third wheel rotation speed detection sensor unit
134: inclination detection sensor unit
135: vehicle speed detection sensor unit
140: Accelerated pedal
190:
191:
193: In-wheel motor control unit

Claims (6)

A plurality of in-wheel motors mounted on each of the plurality of wheels;
A sensor unit for measuring an inclination of the vehicle body;
Controlling the respective in-wheel motors so as to apply an initial torque corresponding to a normal force of each of the wheels set at an initial stage, calculating a normal force of each of the wheels based on the inclination, And a control unit for varying the torque. The method according to claim 1,
And controls the in-wheel motor to vary the in-wheel motor torque of each of the wheels based on the calculated normal force of each of the wheels, when it is determined that the inclination exceeds the inclination range. The method according to claim 1,
Wherein the sensor unit measures a vehicle speed and a rotation speed of each wheel,
Wherein the control unit calculates the slip ratio of each wheel based on the vehicle speed and the rotational speed of each of the wheels, and varies the vertical force of each wheel based on the slip ratio. The method of claim 3,
Wherein the control unit increases the vertical force of the remaining wheels except the smallest one of the wheels when it is determined that the slip ratio of each of the wheels is equal to or greater than a predetermined first set slip rate. The method according to claim 1,
Wherein when the slip ratio of each of the wheels exceeds a predetermined second set slip rate, the control unit controls the in-wheel motor torque to decrease the in-wheel motor torque of the wheel whose slip rate exceeds the second set slip rate, A vehicle that controls a motor. The method according to claim 1,
Wherein the vertical force of each of the wheels according to the inclination is previously stored in the controller.

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