JP6857521B2 - Vehicle control unit - Google Patents

Description

The present invention relates to a vehicle control device that controls a vehicle in response to a change in atmospheric pressure.

In a vehicle equipped with an electric motor, the voltage of the battery is boosted, and the boosted electric power is supplied to the electric motor via an inverter. The voltage of the electric power supplied to the electric motor is adjusted according to the load within a predetermined range not exceeding the dielectric breakdown voltage, which is a physical property value at which insulation breakdown does not occur in the insulating coating between the wires of the motor.

However, when the atmospheric pressure drops, the dielectric breakdown voltage itself becomes low, and if the voltage is adjusted within the same voltage range as before the atmospheric pressure drops, the voltage exceeds the lowered breakdown voltage, causing dielectric breakdown. There is a risk. Therefore, there is known a technique of using a pressure sensor to reduce the maximum value of the voltage supplied to the electric motor (boost limit) so as not to exceed the breakdown voltage when the atmospheric pressure drops (for example, Patent Document 1). 2, 3).

Japanese Unexamined Patent Publication No. 2006-288170 Japanese Unexamined Patent Publication No. 2010-239791 Japanese Unexamined Patent Publication No. 2011-135642

Dielectric breakdown of the electric motor can be avoided by executing the boost limiting according to the decrease of the atmospheric pressure as in the above-mentioned technique. However, when the atmospheric pressure sensor is placed in the interior space of the vehicle, for example, when entering an area where the atmospheric pressure is likely to change, such as a bridge or a high bridge, the response of the atmospheric pressure sensor is delayed and the pressure is increased in response to a sudden change in the atmospheric pressure. The limit may not be met in time, which may lead to insulation destruction of the electric motor.

Therefore, in consideration of the response delay of the barometric pressure sensor, it is conceivable to loosen the threshold value of the barometric pressure for executing the pressurization limitation (to respond with a small change) and execute the pressurization limitation relatively early. However, in this case, as the sensitivity increases, the boosting limit is unnecessarily applied, which affects the running performance.

In view of such a problem, an object of the present invention is to provide a vehicle control device capable of appropriately controlling a vehicle in response to a change in atmospheric pressure.

In order to solve the above problems, the vehicle control device of the present invention includes an electric motor mounted on the vehicle, a booster circuit that boosts the voltage of the battery and supplies it to the electric motor, and a bridge road which is a road provided on the upper surface of the bridge. The movement determination unit includes a movement determination unit that determines whether or not a vehicle enters the road, and a processing execution unit that limits the boost voltage in the booster circuit when the movement determination unit determines that the vehicle enters the bridge road.

The movement determination unit may also determine whether or not the vehicle exits the bridge road, and the processing execution unit may release the boost voltage restriction in the booster circuit when the movement determination unit determines that the vehicle exits the bridge road. ..

A pressure sensor provided in the vehicle interior space to detect the air pressure in the vehicle interior space is further provided, and the processing execution unit may limit the boost voltage in the booster circuit according to the pressure pressure in the vehicle interior space in addition to the determination result of the movement determination unit. Good.

The movement determination unit may determine that the vehicle enters the bridge road based on the image captured in front of the vehicle.

According to the present invention, it is possible to appropriately control the vehicle in response to a change in atmospheric pressure.

It is explanatory drawing explaining the structure of the vehicle control device. It is explanatory drawing which showed the change of the atmospheric pressure on the bridge road. It is explanatory drawing which showed the change of the atmospheric pressure on the bridge road. It is a flowchart which showed the specific process flow of the boost limiting process. It is a timing chart which showed the state transition of a vehicle control device.

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. The dimensions, materials, and other specific numerical values shown in such an embodiment are merely examples for facilitating the understanding of the invention, and do not limit the present invention unless otherwise specified. In the present specification and drawings, elements having substantially the same function and configuration are designated by the same reference numerals to omit duplicate description, and elements not directly related to the present invention are not shown. To do.

(Vehicle control device 100)
FIG. 1 is an explanatory diagram illustrating the configuration of the vehicle control device 100. The vehicle control device 100 operates the engine 110 and the electric motor 112 according to the amount of operation by the driver to obtain the driving force of the vehicle 1. As the electric motor 112, for example, an AC synchronous motor is used. Here, the power of the high-voltage battery (battery) 114 of 100V to 400V is boosted to, for example, 650V by the boost converter (boost circuit) 116, further converted to DC / AC via the inverter 118, and then supplied to the motor 112. Will be done. Then, by adjusting the output of the inverter 118, the rotation of the electric motor 112 is controlled. The traveling speed (vehicle speed) of the vehicle 1 traveling with the driving force of the engine 110 and the electric motor 112 is detected by the vehicle speed sensor 120.

Further, two imaging units 122 are provided in front of the vehicle 1. The image pickup unit 122 is configured to include an image pickup element such as a CCD (Charge-Coupled Device) or a CMOS (Complementary Metal-Oxide Semiconductor), images the outside environment of the vehicle in front of the vehicle 1, and includes at least brightness information. (Color image or monochrome image) can be generated. Further, the imaging unit 122 is arranged so as to be separated from each other in the substantially horizontal direction so that the optical axes of the two imaging units 122 are substantially parallel to each other on the traveling direction side of the vehicle 1. Here, since the two imaging units 122 generate luminance images of different viewpoints, it is possible to grasp the relative distance to the three-dimensional object existing in front. Here, the three-dimensional object is not only a vehicle or a building (for example, a bridge) but also a part thereof (for example, a part of a bridge).

Further, the vehicle 1 is provided with an in-vehicle space 124 for accommodating a driver and other occupants, and by closing the door, the outside of the vehicle 1 and the in-vehicle space 124 can be separated. Further, in the vehicle interior space 124, for example, behind the rear seats, for example, an atmospheric pressure sensor 126 utilizing deformation of the diaphragm is provided, and the atmospheric pressure sensor 126 detects the atmospheric pressure in the vehicle interior space 124.

The control unit (ECU: Engine Control Unit) 128 includes a central control unit 150 and a data holding unit 152, and controls the entire vehicle control device 100. The central control unit 150 is composed of a semiconductor integrated circuit including a central processing unit (CPU), a ROM in which programs and the like are stored, a RAM as a work area, and the like, and is composed of an inverter control unit 160 and a boost limiting unit (processing execution) shown below. Unit) 162, also functions as an external environment recognition unit (movement determination unit) 164. The data holding unit 152 is composed of a RAM, a flash memory, an HDD, and the like, and holds various information necessary for processing of the central control unit 150. Hereinafter, each functional unit of the central control unit 150 will be described.

The inverter control unit 160 adjusts the output of the inverter 118 to rotate and control the electric motor 112. However, the output range of the inverter 118 that can be adjusted by the inverter control unit 160 is limited by the boost voltage (output voltage) of the boost converter 116.

The boost limiting unit 162 sets the boost voltage of the boost converter 116. The boosted voltage is limited to a range that does not exceed the dielectric breakdown voltage, which is a physical property value at which insulation breakdown does not occur in the insulating coating between the wires of the motor 112. The dielectric breakdown voltage changes depending on the atmospheric pressure. Therefore, the boost limiting unit 162 limits the boost voltage according to the atmospheric pressure detected by the atmospheric pressure sensor 126 within a range not exceeding the insulation breakdown voltage corresponding to the atmospheric pressure (hereinafter, simply referred to as “boost limiting”). For example, when the atmospheric pressure drops, the dielectric breakdown voltage drops accordingly, so that the boost limiting unit 162 lowers the boost voltage of the boost converter 116. In this way, it is possible to avoid dielectric breakdown and ensure running safety regardless of changes in atmospheric pressure.

2 and 3 are explanatory views showing changes in atmospheric pressure on the bridge road. As shown in FIG. 2A, the bridge road 170 is a road provided on the upper surface of the bridge including the viaduct, and the atmospheric pressure is likely to change by entering the road (the amount of change in atmospheric pressure is a predetermined pressure fluctuation). It has features (out of range). Here, as shown in FIG. 2B, when the vehicle 1 enters the approach portion (the portion corresponding to the entrance of the bridge road 170) 170a in the bridge road 170 from outside the bridge road 170, as shown in FIG. Immediately after the atmospheric pressure around the electric motor 112 moves to the approaching portion 170a, the atmospheric pressure drops sharply, for example, about 70 Pa, and the dielectric breakdown voltage drops accordingly. It is considered that this is because the atmosphere does not blow through the road in front of the bridge road 170, but the atmosphere blows through on the bridge road 170. Therefore, the boost limiting unit 162 must lower the boost voltage of the boost converter 116.

However, as described above, since the air pressure sensor 126 is arranged in the vehicle interior space 124, for example, the air pressure in the vehicle interior space 124 changes later than the change in the air pressure outside the vehicle 1. Then, the response of the atmospheric pressure sensor 126 may be delayed in response to a sudden change in atmospheric pressure (here, a sudden drop), and the boosting limit may not be in time.

Here, in consideration of the response delay of the barometric pressure sensor 126, it is conceivable that the boost limiting unit 162 relaxes (increases) the threshold value of the atmospheric pressure at which the boost limiting is executed, and executes the boost limiting relatively early. However, in this case, as the sensitivity increases, the boosting limit is unnecessarily applied, which affects the running performance. Therefore, in the present embodiment, it is an object of the purpose of identifying the bridge road 170 through means other than the atmospheric pressure sensor 126, for example, the vehicle exterior environment recognition unit 164, and executing the boosting restriction at an appropriate timing.

Here, the vehicle exterior environment recognition unit 164 acquires a luminance image from each of the two imaging units 122, and sets a block corresponding to a block (aggregate of a plurality of pixels) arbitrarily extracted from one luminance image into the other luminance image. The parallax (depth distance) and the screen position indicating the position of an arbitrary block in the screen are derived by using so-called pattern matching, which is searched from, and the three-dimensional position of each block is derived. Then, the vehicle exterior environment recognition unit 164 identifies a three-dimensional object existing in the vehicle exterior environment, for example, a preceding vehicle traveling in the same direction. Further, when the vehicle exterior environment recognition unit 164 identifies the preceding vehicle in this way, the vehicle 1 is moved so as to avoid a collision with the preceding vehicle (collision avoidance control) or to keep the inter-vehicle distance with the preceding vehicle at a safe distance. Control (adaptive cruise control).

Further, the vehicle exterior environment recognition unit 164 determines whether or not the three-dimensional object existing in the vehicle exterior environment is the approach portion 170a of the bridge road 170. Then, when the vehicle exterior environment recognition unit 164 determines that the three-dimensional object is the approach portion 170a of the bridge road 170, it determines whether or not the vehicle 1 enters the bridge road 170. That is, the vehicle exterior environment recognition unit 164 has an approach portion 170a of the bridge road 170 in the traveling direction, and the relative distance between the vehicle 1 and the approach portion 170a of the bridge road 170 is equal to or less than a predetermined first distance threshold value. Using the vehicle speed of the vehicle speed sensor 120, it is determined whether or not the time to reach the approach portion 170a of the bridge road 170 is within a predetermined first time threshold value.

As a result, when the vehicle exterior environment recognition unit 164 determines that the vehicle 1 enters the bridge road 170, the boost limiting unit 162 limits (lowers) the boost voltage of the boost converter 116. In this way, it is possible to quickly grasp the change in atmospheric pressure and execute the boost limiting at an appropriate timing.

Further, the vehicle exterior environment recognition unit 164 recognizes the exit portion (the portion corresponding to the exit of the bridge road 170) 170b as shown in FIG. 2C while traveling on the bridge road 170, and the exit portion (the portion corresponding to the exit of the bridge road 170) 170b. It is determined whether or not the vehicle 1 exits from the bridge road 170. That is, the vehicle exterior environment recognition unit 164 has an exit portion 170b of the bridge road 170 in the traveling direction, and the relative distance between the vehicle 1 and the exit portion 170b of the bridge road 170 is equal to or less than a predetermined second distance threshold value. Using the vehicle speed of the vehicle speed sensor 120, it is determined whether or not the time to reach the exit portion 170b of the bridge road 170 is within a predetermined second time threshold value. Here, the vehicle outside environment recognition unit 164 determines whether or not the vehicle 1 exits from the bridge road 170, but whether or not the vehicle 1 has exited from the bridge road 170 (whether or not it has passed the exit portion 170b). May be determined.

As a result, when the vehicle exterior environment recognition unit 164 determines that the vehicle 1 leaves the bridge road 170, the boost limiting unit 162 releases (raises) the restriction on the boost voltage of the boost converter 116.

(Boost limiting processing)
FIG. 4 is a flowchart showing a specific flow of the boost limiting process, and FIG. 5 is a timing chart showing the state transition of the vehicle control device 100. Here, the boost limiting process shown in FIG. 4 is repeatedly executed at predetermined intervals.

First, the boost limiting unit 162 determines whether or not the atmospheric pressure detected by the atmospheric pressure sensor 126 is less than a predetermined atmospheric pressure threshold value (S200). As a result, if the detected atmospheric pressure is less than the atmospheric pressure threshold value (YES in S200), the atmospheric pressure flag is set to 1 (S202). Such a barometric pressure flag is a flag indicating whether or not to execute the boosting limit according to the atmospheric pressure detected by the barometric pressure sensor 126, and 1 is for executing the boosting limit and 0 is for canceling the boosting limit. In this way, it is possible to avoid dielectric breakdown and ensure running safety regardless of changes in atmospheric pressure.

Further, if the detected atmospheric pressure is equal to or higher than the atmospheric pressure threshold value (NO in S200), the boost limiting unit 162 determines whether or not the vehicle outside environment recognition unit 164 determines that the vehicle 1 enters the bridge road 170, for example, in the traveling direction. It is determined whether or not there is an approach portion 170a of the bridge road 170 and the relative distance between the vehicle 1 and the approach portion 170a of the bridge road 170 is equal to or less than a predetermined first distance threshold value (S204). As a result, if it is determined that the vehicle 1 enters the bridge road 170 (YES in S204), the bridge flag is set to 1 (S206). Such a bridge flag is a flag indicating whether or not to execute the boosting limit according to the positional relationship with the bridge road 170, and 1 is for executing the boosting limitation and 0 is for canceling the boosting limitation. In this way, it is possible to quickly grasp the change in atmospheric pressure and execute the boost limiting at an appropriate timing.

Further, if it is determined that the vehicle 1 does not enter the bridge road 170 (NO in S204), the barometric pressure flag and the bridge flag are not updated.

Subsequently, the boost limiting unit 162 determines whether or not the atmospheric pressure detected by the atmospheric pressure sensor 126 is equal to or higher than a predetermined atmospheric pressure threshold value (S208). As a result, if the detected atmospheric pressure is equal to or higher than the atmospheric pressure threshold value (YES in S208), the atmospheric pressure flag is set to 0 (S210). Here, the same values are used as the atmospheric pressure threshold value in step S200 and the atmospheric pressure threshold value in step S208, but a hysteresis characteristic may be provided. In this way, the boosting limit can be released in response to the rise in atmospheric pressure, and the traveling performance can be improved.

If the detected atmospheric pressure is less than the atmospheric pressure threshold value (NO in S208), the boost limiting unit 162 determines whether or not the vehicle outside environment recognition unit 164 determines that the vehicle 1 will leave the bridge road 170, for example, in the direction of travel. It is determined whether or not there is an exit portion 170b of the bridge road 170 and the relative distance between the vehicle 1 and the exit portion 170b of the bridge road 170 is equal to or less than a predetermined second distance threshold value (S212). As a result, if it is determined that the vehicle 1 leaves the bridge road 170 (YES in S212), the bridge flag is set to 0 (S214). In this way, the change in atmospheric pressure can be quickly grasped, and the boosting restriction can be released at an appropriate timing.

Further, if it is determined that the vehicle 1 does not leave the bridge road 170 (NO in S212), the barometric pressure flag and the bridge flag are not updated.

Subsequently, the boost limiting unit 162 determines whether or not the atmospheric pressure flag is 1 or the bridge flag is 1 (S216). As a result, if the barometric pressure flag is 1 or the bridge flag is 1 (YES in S216), the boost limiting unit 162 executes the boost limiting (S218).

If the barometric pressure flag is 1 or the bridge flag is not 1 (NO in S216), that is, if the barometric pressure flag is 0 and the bridge flag is 0, the boost limiting unit 162 releases the boost limiting. (S220).

In steps S216 to S220, the following processing is performed. That is, if either or both of the barometric pressure flag and the bridge flag are 1 (logical sum), the boost limiting should be executed in order to avoid dielectric breakdown of the motor 112. Further, even if one of the barometric pressure flag and the bridge flag is 0 (even if it becomes 0), and the other is not 0 (if it is not 0), the boost limiting is executed (continued). Then, when both the atmospheric pressure flag and the bridge flag become 0, it is considered that there is no possibility of dielectric breakdown of the electric motor 112, and the boosting restriction is released.

When such a process is made to correspond to the actual running, it becomes as shown in FIG. That is, when the relative distance becomes equal to or less than the predetermined first distance threshold value (b) before the time (a) when the vehicle actually reaches the approach portion 170a of the bridge road 170, the vehicle exterior environment recognition unit 164 sets the bridge road 170. It is determined that the vehicle 1 enters the vehicle 1, and the boost limiting unit 162 executes the boost limiting from the time (b) accordingly.

Then, as the vehicle 1 enters the bridge road 170 at the time (a), the atmospheric pressure detected by the atmospheric pressure sensor 126 gradually decreases from the time (c), and becomes less than the atmospheric pressure threshold value at the time (d). However, since the boost limiting has already been executed, the boost limiting will not be executed again.

Subsequently, when the relative distance becomes equal to or less than the predetermined second distance threshold value (f) from the time (e) when the vehicle actually reaches the exit portion 170b of the bridge road 170, the vehicle exterior environment recognition unit 164 starts from the bridge road 170. It is determined that the vehicle 1 leaves. However, since the pressurization limit based on the barometric pressure sensor 126 has not been released (atmospheric pressure flag = 1), the pressurization limit continues as it is.

Then, as the vehicle 1 exits from the bridge road 170 at the time (e), the atmospheric pressure detected by the atmospheric pressure sensor 126 gradually rises from the time (e), and becomes equal to or higher than the atmospheric pressure threshold value at the time (g). At the time point (g), both the bridge flag and the atmospheric pressure flag become 0, so the boost limiting unit 162 releases the boost limiting.

By the above-mentioned boost limiting process, in addition to the change in atmospheric pressure by the atmospheric pressure sensor 126, by identifying the road on the bridge, the boost limiting can be executed at an appropriate timing and dielectric breakdown can be avoided regardless of the change in atmospheric pressure. It will be possible.

Further, since the change in atmospheric pressure can be quickly determined in this way, it is not necessary to loosen (increase) the threshold value of the atmospheric pressure for executing the pressurization limitation in consideration of the response delay of the barometric pressure sensor 126, and unnecessary pressurization limitation is prevented. , It is possible to improve the running performance.

Although the preferred embodiment of the present invention has been described above with reference to the accompanying drawings, it goes without saying that the present invention is not limited to such an embodiment. It is clear that a person skilled in the art can come up with various modifications or modifications within the scope of the claims, and it is understood that these also naturally belong to the technical scope of the present invention. Will be done.

For example, in the above-described embodiment, the vehicle exterior environment recognition unit 164 has been described as a movement determination unit for determining whether or not the vehicle 1 enters the bridge road 170 in which the amount of change in atmospheric pressure is outside the predetermined atmospheric pressure fluctuation range. As long as the entry of the vehicle 1 into the bridge road 170 can be determined, various existing devices such as a GPS, a car navigation system, and a laser ranging device can be used.

Further, in the above-described embodiment, the vehicle exterior environment recognition unit 164 as the movement determination unit has been described with an example of determining whether or not the three-dimensional object existing in the vehicle exterior environment is the approach portion 170a of the bridge road 170. It is sufficient to determine that the bridge road 170 exists in the traveling direction without specifying that it is the approaching portion 170a. In this way, it is possible to prevent unnecessary boosting restrictions and improve running performance.

Further, in the above-described embodiment, the boost limiting unit 162 is cited as the processing execution unit that executes a predetermined process for the vehicle 1, and when it is determined that the vehicle 1 enters the bridge road 170, the boost voltage in the boost converter 116 is limited. Although an example has been described, the processing target of the processing execution unit is not limited to such a case, and for example, the intake air of the engine 110 is increased (throttle is opened) in response to a sudden change in the atmospheric pressure, and the processing target is in response to a change in the atmospheric pressure. It can be applied to various processes to be executed in the vehicle 1.

Further, in the above-described embodiment, the HEV (hybrid vehicle) having the engine 110 and the electric motor 112 as the drive source is mentioned, but it goes without saying that the EV (electric vehicle) which uses only the electric motor 112 as the drive source can also be applied.

The present invention can be used in a vehicle control device that controls a vehicle in response to a change in atmospheric pressure.

1 Vehicle 100 Vehicle control device 112 Electric motor 114 High-voltage battery (battery)
116 Boost converter (boost circuit)
124 Interior space 126 Barometric pressure sensor 162 Boost limiting unit (processing execution unit)
164 External environment recognition unit (movement judgment unit)
170 Hashigami Road

Claims (4)

The electric motor mounted on the vehicle and
A booster circuit that boosts the voltage of the battery and supplies it to the motor,
And determining whether the move judgment unit the vehicle on bridge road, road provided on the upper surface of the bridge enters,
When the movement determination unit determines that the vehicle enters the bridge road, the processing execution unit that limits the boost voltage in the booster circuit and
Vehicle control device. The movement determination unit also determines whether or not the vehicle leaves the bridge road, and determines whether or not the vehicle leaves.
The process execution unit, when the movement determination section determines that the vehicle from the Hashigami road exits, the vehicle control apparatus according to claim 1 for releasing the limit of the boost voltage at the boost circuit. It is provided in the vehicle interior space and is further equipped with an atmospheric pressure sensor that detects the atmospheric pressure in the vehicle interior space.
The vehicle control device according to claim 1 or 2 , wherein the processing execution unit limits the boost voltage in the booster circuit according to the atmospheric pressure in the vehicle interior space in addition to the determination result of the movement determination unit. The vehicle control device according to any one of claims 1 to 3 , wherein the movement determination unit determines that the vehicle enters the bridge road based on an image of the front of the vehicle.

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