JP2006062461A - Vehicle control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To execute a proper braking control to an abnormality happening on a vehicle. <P>SOLUTION: An abnormality detecting section 202 detects an abnormality happening on the vehicle. An abnormality rank judging section 204 ranks the abnormality depending on the affecting degree to the running of the vehicle of the detected abnormality. A deceleration degree setting section 206 sets a deceleration degree in response to the judged rank. A brake controlling section 210 sends a command to the braking means of the vehicle to decelerate to a specified speed by the set deceleration degree. Thus, the vehicle can be braked by a different deceleration speed for each content of abnormality, and an effect which is given to the running stability of the vehicle, an impact to passengers, and an effect which is given to the surrounding traffic can be suppressed. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a vehicle control technique, and more particularly to a vehicle braking control technique when an abnormality occurs in the vehicle.

In general, it is preferable to detect an abnormality such as a failure that occurs in a vehicle and perform processing such as turning on a warning lamp, prompting a stop, or motion control of the vehicle from the viewpoint of ensuring safe vehicle travel. For this reason, techniques for performing appropriate processing on a vehicle in which an abnormality has occurred have been proposed. For example, Patent Document 1 discloses a technique for stabilizing the motion state of a vehicle by applying braking force or reducing engine output when the motion control device becomes abnormal during motion control of the vehicle. Has been.
JP-A-10-147225

  However, in the above-mentioned Patent Document 1, it is not described that the degree of abnormality is determined or control according to it is performed. In many cases, an appropriate process for an abnormality occurring in a vehicle cannot be determined uniformly. For example, when the abnormality that has occurred is a relatively mild abnormality, if a process such as deceleration is performed rapidly, smooth running may be hindered, or the driver may be shocked.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a vehicle control technique for executing appropriate braking control for an abnormality occurring in the vehicle.

  An aspect of the present invention includes a braking unit that brakes a vehicle, an abnormality detecting unit that detects an abnormality that occurs in the vehicle, and an abnormality that ranks the abnormality according to the degree of influence of the detected abnormality on the running of the vehicle. Rank determining means, deceleration setting means for setting a deceleration according to the determined rank, and braking control means for instructing the braking means to decelerate to a predetermined vehicle speed with the set deceleration. A vehicle control device is provided.

  According to this aspect, when an abnormality occurs, a deceleration according to the rank of the abnormality is set, so that the vehicle can be braked with a different deceleration for each abnormality content. Here, the braking means includes both those that generate a braking force with regenerative energy such as a rotating electrical machine and those that generate a braking force with frictional force such as a disc brake.

  The deceleration setting means may set the deceleration higher as the abnormality rank increases. According to this, when the rank of the abnormality is determined and the rank is low, that is, when the abnormality is not serious, braking is performed at a reduced speed, so the influence on the running stability of the vehicle, the impact on the occupant, the surroundings The impact on traffic can be minimized. Further, when the rank is high, that is, when the abnormality is serious, braking is performed at a high deceleration, so that the vehicle speed is lowered early, and damage to the vehicle due to the occurrence of the abnormality can be reduced.

  Another aspect of the present invention ranks the abnormalities according to the braking means for braking the vehicle, the abnormality detecting means for detecting an abnormality occurring in the vehicle, and the degree of influence of the detected abnormality on the running of the vehicle. Abnormal rank determination means, limit vehicle speed setting means for setting a limit vehicle speed lower than the current vehicle speed according to the determined rank, and braking for instructing the braking means to decelerate the vehicle speed to the set limit vehicle speed And a control means.

  According to this aspect, when the abnormality occurs, the limited vehicle speed corresponding to the abnormality rank is set, so that the vehicle can be decelerated to a different vehicle speed for each abnormality content.

  The limit vehicle speed setting means may set the limit vehicle speed lower as the abnormality rank increases. According to this, since the vehicle speed is kept low when the rank of abnormality is high, the safety of the vehicle can be ensured.

  According to the vehicle control device of the present invention, the deceleration or the speed limit is set according to the abnormality rank of the vehicle, so that the vehicle can be braked in a more appropriate manner for each abnormality content.

  The present invention provides a vehicle control technique that realizes braking in accordance with a situation by changing a braking control method in accordance with a lightness of the degree of abnormality when an abnormality occurs in the vehicle. Hereinafter, the present invention will be described based on embodiments.

Embodiment 1 FIG.
FIG. 1 is a diagram showing an overall configuration of a vehicle 10 on which a vehicle control device according to Embodiment 1 is mounted. The vehicle 10 is an in-wheel motor type electric vehicle in which a motor is built in the wheel 100. This in-wheel motor system is characterized by the fact that transmission system parts and installation space can be omitted, and loss due to transmission can be eliminated, compared to a system that distributes the output of a single motor to each wheel. There is. The structure of the wheel 100 incorporating the motor will be described later with reference to FIG.

  Each wheel 100 is provided with a motor 52. Direct current power is supplied from the battery 26 mounted on the vehicle body 12 to the amplifier 24 installed on the vehicle body side corresponding to the motor 52. The amplifier 24 includes an inverter, converts the supplied DC power into a three-phase AC voltage, and supplies the converted voltage to the motor 52. The motor 52 is rotationally driven by an AC voltage, thereby rotating the wheel 100 and causing the vehicle 10 to travel. The motor 52 can also exert a braking force by a regenerative brake generated by the rotation of wheels during inertial running. The regenerated electric power is charged in the battery 26.

  The output of the motor 52 is controlled by an electronic control device 200 (hereinafter referred to as “ECU 200”) mounted on the vehicle body 12. The ECU 200 is communicably connected to the amplifier 24 and gives a torque command value for the motor 52 to the amplifier 24. The amplifier 24 performs PWM control of the built-in inverter, and controls the motor 52 so as to exert torque according to the torque command value. The motor 52 is equipped with an encoder (not shown) that detects the rotational speed of the rotor, and the output of this encoder is supplied to the ECU 200 via the amplifier 24. By configuring a feedback circuit with a signal from the encoder, the motor 52 can be controlled with high accuracy.

  The vehicle body 12 is also provided with an accelerator operation amount sensor 30 for detecting the operation amount of the accelerator pedal by the driver, a brake operation amount sensor 32 for detecting the operation amount of the brake pedal, and a steering sensor 34 for detecting the rotation amount of the steering wheel. ing. These detected values are transmitted to the ECU 200.

  The ECU 200 calculates a torque command value corresponding to the operation amount of the accelerator pedal and the brake pedal, and transmits the information to the amplifier 24, thereby realizing acceleration / deceleration of the vehicle. The ECU 200 can also make the turning easier by changing the number of rotations of each wheel 100 when turning the vehicle 10 based on the rotation amount of the steering wheel. Further, the ECU 200 constantly monitors the motion state of the vehicle and the operation state of various devices based on the detection values from the various sensors mounted on the vehicle body 12 or the wheel 100. An appropriate command is given to the motor 52 of the wheel 100 to operate the vehicle so as to ensure the traveling safety. This will be described later with reference to FIG.

  A wheel speed sensor 42 is provided corresponding to each wheel 100. The wheel speed sensor 42 is configured using, for example, a resolver that generates a pulse signal for each minute angular position displacement, and the signal is sent to the ECU 200. Each wheel 100 is equipped with a sensor 54 that detects various states of the wheel. The sensors 54 are collectively represented. Specifically, there are an air pressure sensor that detects the pressure of the tire air chamber, a vibration sensor that detects the vibration of the tire, a temperature sensor that detects the temperature of the tread rubber of the tire, and the like. included. The detected various information is wirelessly transmitted to the vehicle body 12 via the wheel side communication device 56 attached to the wheel of the wheel 100 or the like.

  The vehicle body 12 is provided with a vehicle body side communication device 40, which receives a signal sent from the wheel side communication device 56 of each wheel 100 and supplies it to the ECU 200.

  The vehicle body 12 is also provided with a sensor 58 for detecting the motion state of the vehicle and the operation states of various devices. The sensors 58 are collectively represented. Specifically, a roll sensor and a yaw rate sensor for detecting the acceleration of the vehicle, a voltage sensor for knowing the remaining amount of the battery, and temperatures of various devices mounted on the vehicle. And a temperature sensor for detecting.

  FIG. 2 is a diagram schematically showing the structure of the wheel 100 on which the motor 52 is mounted. In FIG. 2, the sensor 54 and the wheel-side communication device 56 are omitted. The wheel 100 mainly includes a tire 102, a wheel 104, a motor housing 110 that houses a motor 52, and a speed reduction mechanism 120. The speed reduction mechanism 120 is coupled to a suspension device extending from a vehicle body (not shown) on the left side of FIG.

  The wheel 104 on which the tire 102 is mounted is fixed to the hub wheel 108 by a hub nut 106. The hub wheel 108 is fixed to the output shaft 112 protruding from the motor housing 110 and rotates together with the output shaft 112. A speed reduction mechanism 120 that houses a gear reduction device 118 that reduces the rotation of the rotor 116 of the motor 52 is connected and fixed to the side surface of the motor housing 110 on the vehicle body side. The rotational output of the motor 52 is transmitted to the output shaft 112 and the wheel 104 via the gear reducer 118, and the wheel 104 is rotationally driven together with the tire 102 by the transmitted rotational force. The motor housing 110 is manufactured by, for example, aluminum die casting in consideration of reduction in unsprung weight and durability of a suspension (not shown), ease of manufacturing, and the like.

  As shown in FIG. 2, the motor housing 110 has a bowl shape that can be divided into two in the left-right direction, and an opening through which an output shaft 112 extending from the speed reduction mechanism 120 side can be inserted on the side facing the wheel 104. 122 is formed. A bearing 124 is disposed in the opening 122 and rotatably supports the output shaft 112 with respect to the motor housing 110. On the other hand, an opening 126 through which the rotor 116 can be inserted is formed on the connection side of the motor housing 110 with the speed reduction mechanism 120. A bearing 128 is disposed in the opening 126 and rotatably supports the rotor 116 with respect to the motor housing 110.

  A stator 130 is fixed to the inner wall surface of the motor housing 110, and a rotor 116 is disposed on the inner peripheral side of the stator 130. The stator 130 includes an iron core 132a formed of laminated electromagnetic steel plates and a three-phase coil 132b wound around each tooth portion of the iron core 132a.

  The rotor 116 is formed with an insertion hole 116a through which the output shaft 112 is rotatably inserted at the center thereof over the entire axial length. The output shaft 112 is rotatably held independently of the rotor 116 by a plurality of bearings 134 disposed in the insertion hole 116a. The rotor 116 includes a large-diameter portion that faces the stator 130 and a small-diameter portion that extends to the inside of the speed reduction mechanism 120. A plurality of permanent magnets 136 are arranged on the outer peripheral surface of the large diameter portion. Thus, by sequentially supplying current to the coil 132b at a predetermined timing, a rotating magnetic field can be generated in the stator 130 and the rotor 116 can be rotated.

  A rotor gear 140 that meshes with the first gear 138 a of the gear reducer 118 is formed at the tip of the small diameter portion of the rotor 116. The gear shaft 142 that supports the first gear 138 a is pivotally supported by a plurality of bearings 144. A small-diameter second gear 138b is fixed to the gear shaft 142, and the second gear 138b meshes with a large-diameter third gear 138c fixed to the output shaft 112. The output shaft 112 is also supported by a bearing 146 disposed inside the speed reduction mechanism 120 to ensure smooth rotation.

  In the wheel 100 as described above, the rotational force of the rotor 116 is decelerated by the gear reducer 118 and transmitted to the output shaft 112 and transmitted to the wheel 104, and finally the tire 102 is rotationally driven.

  By the way, in such an in-wheel motor type vehicle, an abnormality of one motor affects the running performance of the entire vehicle, so it is necessary to consider in advance how to deal with the abnormality. In addition, when an abnormality occurs, it is preferable to decelerate the vehicle in order to ensure safety and to quickly recover from the abnormality even if it is a minor abnormality. Therefore, the vehicle control apparatus according to the present embodiment reduces the vehicle speed when an abnormality occurs in the vehicle.

  FIG. 3 is a functional block diagram illustrating a configuration of a portion of ECU 200 that is involved in vehicle braking control when an abnormality occurs. Each block shown here can be realized in hardware by an element and a mechanical device including a computer CPU and memory, and in software by a computer program or the like. It is drawn as a functional block to be realized. Accordingly, those skilled in the art will understand that these functional blocks can be realized in various forms by a combination of hardware and software.

  The abnormality detection unit 202 detects an abnormality occurring in the vehicle 10 based on information sent from the wheel side sensor 54, the vehicle body side sensor 58, the wheel speed sensor 42, the amplifier 24, and the like. Abnormalities mentioned here include abnormalities that may affect the normal running of the vehicle, such as mechanical abnormalities in the braking / driving system such as the motor 52 and the speed reduction mechanism, electrical abnormalities in the sensors, etc. Is included.

  The abnormality rank determination unit 204 classifies the abnormality of the vehicle 10 detected by the abnormality detection unit 202 as one of the preset abnormality ranks in consideration of the degree of influence on the running stability of the vehicle. In the present embodiment, for simplicity of explanation, the abnormality rank is divided into two ranks of “high importance” and “low importance”. Abnormalities classified as “high importance” include, for example, abnormal heating and abnormal vibration of bearing parts of motors and deceleration mechanisms, application of excessive current to the stator, abnormal heating of tires, malfunction of control systems such as ECUs, etc. As described above, the abnormality is such that the vehicle should be immediately decelerated to prevent further abnormality. Abnormalities classified as “low importance” do not immediately cause problems in vehicle travel, such as tire pressure drop, electrical equipment abnormality, sensor failure such as roll sensor or yaw rate sensor. Conceivable abnormalities are included.

  Note that the above-described abnormality classification is merely an example, and other abnormalities can be classified into each rank. In addition, even if the abnormality is of the same type, there may be a case where it should be classified into different ranks according to the traveling state of the vehicle, the type of vehicle, the traffic situation, and the like.

The deceleration setting unit 206 sets a predetermined vehicle deceleration according to the abnormality rank determined by the abnormality rank determination unit 204. For example, the deceleration A ₁ (eg, 0.1 G) is set when the abnormality rank is “high importance”, and the deceleration A ₂ (eg, 0.01 G) is set when the abnormality rank is “low importance”. To do. The braking control unit 210 sends a torque command signal to the amplifier 24 so as to decelerate the vehicle 10 to a predetermined target vehicle speed V _s (for example, 30 km / h) at the deceleration set by the deceleration setting unit 206. put out.

FIG. 4 is a diagram illustrating the difference in vehicle deceleration according to the present embodiment. It is assumed that the abnormality detection unit 202 detects the occurrence of an abnormality at time t ₁ while the vehicle is traveling at the vehicle speed V ₀ . Depending on the rank of the classified by failure rank determination unit 204 abnormalities, decelerates deceleration _{A 1} or _{A 2 (A 1> A 2} ) to a predetermined target vehicle speed _{V s.}

FIG. 5 is a flowchart of vehicle braking control when an abnormality occurs according to this embodiment. When the abnormality detection unit 202 detects the occurrence of an abnormality in the vehicle (Y in S10), the abnormality rank determination unit 204 classifies the abnormality into a rank of “high importance” or “low importance” (S12). . Subsequently, the deceleration setting unit 206 determines whether or not the current vehicle speed is _{equal to} or higher than a predetermined target vehicle speed Vs (S14). If the current vehicle speed is less than the target vehicle speed (N in S14), this flow ends. If the vehicle speed is equal to or higher than the target vehicle speed (Y in S14), then, it is determined whether the abnormality rank is “high importance” or “low importance” (S16). If the abnormality rank is “high importance” (Y in S16), the deceleration setting unit 206 sets the deceleration to large (A ₁ ) (S18), and if the abnormality rank is “low importance” (S18). N in S16, the deceleration is set to small (A ₂ ) (S20). Then, the braking control unit 210 brakes the vehicle to the target vehicle speed with the set deceleration (S22).

  Regardless of the severity of an abnormality that has occurred in the vehicle, if braking is always performed at a constant deceleration, it may cause excessive impact and psychological burden on the driver, or may prevent the following vehicle from running. . On the other hand, according to the first embodiment, when the abnormality rank is low, that is, when the abnormality is not serious, braking is performed at a reduced speed, so that the influence on the running stability of the vehicle, the impact on the occupant, the surroundings The impact on traffic can be minimized. Conversely, when the abnormality rank is high, that is, when the abnormality is serious, braking is performed at a high deceleration, so that the vehicle can be brought to a low vehicle speed at an early stage, and damage to the vehicle and on-board equipment due to the occurrence of the abnormality. Can be reduced.

Embodiment 2. FIG.
In the first embodiment, it has been described that the deceleration is changed according to the abnormal weight, but in the second embodiment, the vehicle speed, which is the result of deceleration, is changed. Since the configuration of the vehicle 10 and the wheel 100 on which the vehicle control device according to the second embodiment is mounted is the same as that of the first embodiment, the description thereof is omitted.

  FIG. 6 is a functional block diagram of ECU 200 according to the second embodiment. Since the abnormality detection unit 202 and the abnormality rank determination unit 204 are the same as those in the first embodiment, the same reference numerals are given and detailed description thereof is omitted.

The limit vehicle speed setting unit 208 sets a predetermined limit vehicle speed according to the abnormality rank determined by the abnormality rank determination unit 204. For example, if the abnormal rank is “high importance”, the vehicle speed is limited to V ₁ (for example, 10 km / h), and if the abnormal rank is “low importance”, the vehicle speed is limited to V ₂ (for example, 30 km / h). To do. The braking control unit 210 issues a torque command signal to the amplifier 24 so as to decelerate the vehicle 10 to the limit vehicle speed set by the limit vehicle speed setting unit 208 at a predetermined deceleration.

FIG. 7 is a diagram for explaining a difference in the limited vehicle speed according to the present embodiment. It is assumed that the abnormality detection unit 202 detects the occurrence of an abnormality at time t ₁ while the vehicle is traveling at the vehicle speed V ₀ . Depending on the rank of the classified by failure rank determination unit 204 abnormal decelerates up to the limit set by the predetermined deceleration _{A s} vehicle speeds _{V 1} to or _{V 2 (V 1 <V 2} ).

FIG. 8 is a flowchart of vehicle deceleration control when an abnormality occurs according to this embodiment. When the abnormality detection unit 202 detects an abnormality of the vehicle (Y in S30), the abnormality rank determination unit 204 classifies the abnormality into a rank of “high importance” or “low importance” (S32). Subsequently, it is determined whether the abnormality rank is “high importance” or “low importance” (S34). If the abnormality rank is “high importance” (Y in S34), the limit vehicle speed setting unit 208 determines the limit vehicle speed. Is set to the low vehicle speed (V ₁ ) (S36), and if the abnormality rank is “low importance” (N in S34), the limit vehicle speed is set to the high vehicle speed (V ₂ ) (S38). Subsequently, the limit vehicle speed setting unit 208 determines whether or not the current vehicle speed is equal to or higher than the set limit vehicle speed (S40). If the current vehicle speed is less than the limit vehicle speed (N in S40), this flow is terminated. If the current vehicle speed is greater than or equal to the limit vehicle speed (Y in S40), the braking control unit 210 reduces the vehicle speed to the limit vehicle speed with a predetermined deceleration. Decelerate (S42).

  As described above, according to the second embodiment, when the abnormality rank is low, that is, when the abnormality is not serious, braking is performed at a higher limit vehicle speed, so that the influence on surrounding traffic is reduced. Can do. On the contrary, when the abnormality rank is high, that is, when the abnormality is serious, the vehicle safety can be ensured by braking to a lower limit vehicle speed.

  The present invention has been described above based on the embodiment. It should be understood by those skilled in the art that these embodiments are exemplifications, and that various modifications can be made to the combination of each component and each processing process, and such modifications are also within the scope of the present invention. Hereinafter, such modifications will be described.

  In the embodiment, it has been described that the rank of abnormality is classified into two ranks of “high importance” and “low importance”. However, the rank may be classified into three or more ranks. Even in the case where the rank is increased, it is the same as in the above-described embodiment that the vehicle is decelerated under a predetermined condition according to the rank. In this case, for example, the braking control is not performed in the case of an abnormality classified into the lowest importance rank, and the vehicle may be controlled to stop in the case of the abnormality classified in the highest importance rank. Good.

  It is also possible to combine Embodiments 1 and 2. That is, the deceleration and the limit vehicle speed can be combined according to the degree of abnormality. For example, when the abnormality rank determination unit classifies the detected abnormality into three abnormality ranks of large, medium, and small, and a deceleration / restriction vehicle speed setting unit (not shown) has a large abnormality rank, High deceleration and low limit vehicle speed are set, when the abnormal rank is medium, the reduced speed is set to low limit vehicle speed, and when the abnormal rank is small, the reduced speed is set to high limit vehicle speed. Good. In this way, fine braking control according to the type of abnormality can be performed.

  The abnormality rank determination unit may classify the abnormality into different ranks according to the traveling speed of the vehicle when the abnormality occurs. For example, when the running speed of the vehicle is equal to or higher than a threshold (for example, 80 km / h), it is preferable to decelerate early. Therefore, even if the abnormality is normally classified as “low importance”, “ It can be categorized as “important” to increase the deceleration.

  At the time of braking control, a tail lamp may be blinked to notify the occurrence of an abnormality to the surroundings, or an informing means for notifying an occupant in the vehicle of the occurrence of the abnormality may be provided.

  In the above-described embodiment, a vehicle equipped with an in-wheel motor that can be controlled independently for each wheel has been described. However, the present invention is also applied to a vehicle that distributes the driving force generated by a single motor to four wheels. Can do. Further, in the embodiment, it is described that the vehicle is braked by the regenerative brake of the motor. However, a mechanical brake (for example, a disc brake) (not shown) is provided in each wheel, and the braking control unit has a vehicle speed of a certain level or more. At this time, or always, the mechanical brake may be operated so as to assist the regenerative brake.

1 is an overall configuration diagram of a vehicle equipped with a vehicle control device according to Embodiment 1. FIG. It is the figure which showed the structure of the wheel typically. 3 is a functional block diagram of an ECU according to Embodiment 1. FIG. It is a graph explaining the difference in the deceleration set by the deceleration setting part. 3 is a flowchart of vehicle braking control when an abnormality occurs according to Embodiment 1. 6 is a functional block diagram of an ECU according to Embodiment 2. FIG. It is a graph explaining the difference in the limit vehicle speed set by the limit vehicle speed setting part. 6 is a flowchart of vehicle braking control when an abnormality occurs according to Embodiment 2.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Vehicle, 12 Car body, 24 Amplifier, 30 Accelerator operation amount sensor, 32 Brake operation amount sensor, 34 Steering sensor, 42 Wheel speed sensor, 52 Motor, 54 Wheel side sensor, 100 Wheel, 200 ECU, 202 Abnormality detection part, 204 Abnormal rank determination unit, 206 deceleration setting unit, 208 limit vehicle speed setting unit, 210 braking control unit.

Claims (4)

Braking means for braking the vehicle;
An abnormality detection means for detecting an abnormality occurring in the vehicle;
An abnormality rank determination means for ranking the abnormality according to the degree of influence of the detected abnormality on the running of the vehicle;
Deceleration setting means for setting a deceleration according to the determined rank;
Braking control means for instructing the braking means to decelerate to a predetermined vehicle speed at a set deceleration;
A vehicle control device comprising:   The vehicle control device according to claim 1, wherein the deceleration setting means sets the deceleration higher as the abnormality rank increases. Braking means for braking the vehicle;
An abnormality detection means for detecting an abnormality occurring in the vehicle;
An abnormality rank determination means for ranking the abnormality according to the degree of influence of the detected abnormality on the running of the vehicle;
In accordance with the determined rank, limit vehicle speed setting means for setting a limit vehicle speed lower than the current vehicle speed,
Braking control means for commanding the braking means to decelerate the vehicle speed to a set limit vehicle speed;
A vehicle control device comprising: 4. The vehicle control device according to claim 3, wherein the limit vehicle speed setting means sets the limit vehicle speed lower as the rank of the abnormality increases.

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