JP2023141708A - Vehicle control device - Google Patents

Abstract

To reduce a difference between a target deceleration and an actual deceleration.SOLUTION: A vehicle control device comprises a vehicle speed acquisition unit, a target deceleration acquisition unit, a predicted deceleration calculation unit, and a control unit. The predicted deceleration calculation unit calculates a first predicted deceleration, which is a predicted value of deceleration of a vehicle when a first auxiliary brake operation and a second auxiliary brake operation are not performed, and a second predicted deceleration, which is a predicted value of deceleration of the vehicle when the first auxiliary brake operation is performed and the second auxiliary brake operation is not performed. The control unit controls a plurality of auxiliary brake devices in such a manner that the first auxiliary brake operation is performed when the speed of the vehicle is a first threshold or more and a target deceleration is larger than the first predicted deceleration, and that the second auxiliary brake operation is performed when the speed of the vehicle is a second threshold or more larger than the first threshold and the target deceleration is larger than the second predicted deceleration.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to a vehicle control device.

2. Description of the Related Art Devices are known that perform braking support control to decelerate a vehicle by controlling a main brake device and an auxiliary brake device. For example, Patent Document 1 discloses that a main brake and multiple types of auxiliary brakes are installed in a vehicle, and a target deceleration for the own vehicle is calculated from the inter-vehicle distance to the preceding vehicle and the relative speed with respect to the preceding vehicle. This document describes an auto-cruise control device that compares deceleration with a plurality of threshold values corresponding to a plurality of types of auxiliary brakes, and operates auxiliary brakes in order of decreasing deceleration according to a target deceleration.

Japanese Patent Application Publication No. 2005-263098

The deceleration that occurs in a vehicle due to the operation of the auxiliary brake depends on driving conditions such as the speed and weight of the vehicle. Therefore, if the auxiliary brake to be activated is determined by comparing the target deceleration with a plurality of threshold values without considering the driving state of the vehicle, as in the device described in Patent Document 1, the target deceleration and There may be a difference between this and the actual deceleration. For example, if the vehicle is traveling at low speed, even if the auxiliary brake system is activated, it will not be possible to obtain the same deceleration as when the vehicle is traveling at high speed, and if the vehicle is loaded with cargo and weighs If the cargo is increasing, even if the auxiliary brake system is activated, it will not be possible to obtain the same deceleration as when there is no cargo on board.

Therefore, the present disclosure describes a vehicle control device that can reduce the difference between the target deceleration and the actual deceleration.

In one aspect, a vehicle control device is provided that controls the operation of a main brake that applies braking force to a vehicle and a plurality of auxiliary brake devices. This vehicle control device includes a vehicle speed acquisition section that acquires the speed of the vehicle, a target deceleration acquisition section that acquires the target deceleration of the vehicle, a predicted deceleration calculation section that calculates a predicted value of the deceleration of the vehicle, and a vehicle speed acquisition section that acquires the vehicle speed. and a control unit that controls the operation of the main brake and the plurality of auxiliary brakes based on the predicted value of the deceleration. The plurality of auxiliary brake devices are capable of executing a first auxiliary brake operation and a second auxiliary brake operation that applies a larger braking force to the vehicle than the first auxiliary brake operation, and the predicted deceleration calculation unit is capable of performing a first auxiliary brake operation. The first predicted deceleration is a predicted value of the vehicle deceleration when the auxiliary brake operation and the second auxiliary brake operation are not performed, and the first predicted deceleration when the first auxiliary brake operation is performed and the second auxiliary brake operation is not performed. a second predicted deceleration that is a predicted value of the vehicle's deceleration, and when the speed of the vehicle is equal to or higher than the first threshold and the target deceleration is larger than the first predicted deceleration. the first auxiliary brake operation is executed, and the second auxiliary brake operation is executed when the speed of the vehicle is equal to or higher than a second threshold value that is greater than the first threshold value, and the target deceleration is greater than the second predicted deceleration. control multiple auxiliary brake devices so that

The vehicle control device of this aspect calculates a predicted value of deceleration and compares the predicted value of deceleration with the target deceleration to control the operation of a plurality of auxiliary brake devices. The difference from the actual deceleration can be reduced. Additionally, it is generally difficult for auxiliary brake devices to perform precise braking control like the main brake, so if the auxiliary brake is activated while driving at low speed, deceleration will rapidly increase, worsening ride comfort. There is a risk that In this vehicle control device, since the auxiliary brake device is operated when the speed of the vehicle is above a certain value, deterioration of ride comfort can be suppressed.

The vehicle control device of one embodiment further includes a vehicle weight acquisition unit that acquires the weight of the vehicle, and the plurality of auxiliary brake devices perform a third auxiliary brake operation that applies a larger braking force to the vehicle than the second auxiliary brake operation. , and a fourth auxiliary brake operation that applies a larger braking force to the vehicle than the third auxiliary brake operation, and the predicted deceleration calculation unit is capable of performing the first auxiliary brake operation and the second auxiliary brake operation. The third predicted deceleration is a predicted value of the deceleration of the vehicle when the third auxiliary brake operation and the fourth auxiliary brake operation are not performed, the first auxiliary brake operation, the second auxiliary brake operation, and the third auxiliary brake operation. The controller further calculates a fourth predicted deceleration, which is a predicted value of the deceleration of the vehicle when the brake operation is performed and the fourth auxiliary brake operation is not performed, and the control unit determines that the speed of the vehicle is lower than the second threshold value. the third auxiliary brake operation is executed when the target deceleration is greater than a third predicted deceleration, and the speed of the vehicle is greater than or equal to a fourth threshold greater than the second threshold; A plurality of auxiliary brake devices are controlled so that a fourth auxiliary brake operation is executed when the weight of the vehicle is greater than a fifth threshold and the target deceleration is greater than a fourth predicted deceleration. In this vehicle control device, since the fourth brake operation is performed when the weight of the vehicle is equal to or greater than a certain value, deterioration in ride comfort can be suppressed.

In one embodiment, the predicted deceleration calculation unit is a predicted value of the deceleration of the vehicle when the first auxiliary brake operation, the second auxiliary brake operation, the third auxiliary brake operation, and the fourth auxiliary brake operation are performed. The control unit may further calculate a fifth predicted deceleration, and operate the main brake when the target deceleration is larger than the fifth predicted deceleration. In this embodiment, the difference between the target deceleration and the deceleration of the vehicle can be reduced while suppressing the use of the main brake.

According to one aspect and various embodiments of the present invention, the difference between the target deceleration and the actual deceleration can be reduced.

FIG. 1 is a block diagram showing a functional configuration of a vehicle control device according to an embodiment. 3 is a flowchart showing the flow of processing of the vehicle control device. 3 is a flowchart showing a continuation of FIG. 2.

Hereinafter, vehicle control devices according to various embodiments will be described in detail with reference to the drawings. In each drawing, the same or equivalent parts are given the same reference numerals, and duplicate explanations of the same or equivalent parts will be omitted.

FIG. 1 is a block diagram showing the functional configuration of a vehicle control device according to an embodiment. The vehicle control device 10 is mounted on the vehicle 1 and executes braking support control to decelerate the vehicle. The vehicle 1 on which the vehicle control device 10 is mounted is, for example, a cargo vehicle such as a truck or a tractor that carries cargo. Note that the vehicle 1 may be a large passenger car such as a bus, a regular passenger car, a small vehicle, or a light vehicle.

As shown in FIG. 1, the vehicle 1 includes an external sensor 2, an internal sensor 3, a main brake device 5, a plurality of auxiliary brake devices 6, and a vehicle control device 10.

External sensor 2 detects information about the external environment of vehicle 1 . As the external sensor 2, for example, a camera is used. The camera captures an image in front of the vehicle 1. The camera may be a monocular camera or a stereo camera. A stereo camera has two imaging units arranged to reproduce binocular parallax. The imaging information of the stereo camera also includes information in the depth direction. The external sensor 2 may include a radar sensor that transmits electromagnetic waves around the vehicle 1, receives reflected waves from surrounding objects, and detects objects.

Internal sensor 3 collects various information about vehicle 1 . Internal sensor 3 includes a vehicle speed sensor and a weight sensor. The vehicle speed sensor detects the speed of the vehicle 1 (hereinafter referred to as "vehicle speed"). As the vehicle speed sensor, for example, a wheel speed sensor that is attached to a wheel or a drive shaft of a vehicle and detects the rotational speed of the wheel is used. The weight sensor measures the weight of the vehicle 1 (hereinafter referred to as "vehicle weight"). The vehicle speed sensor and the weight sensor output information indicating the measured vehicle speed and vehicle weight to the vehicle control device 10.

The main brake device 5 is a brake device that is responsible for the main braking of the vehicle 1, and is, for example, a service brake. The main brake device 5 is provided at each wheel of the vehicle 1, and applies braking force to the vehicle 1 by applying a frictional force to the wheels according to the amount of operation of the brake pedal.

The plurality of auxiliary brake devices 6 are braking devices that perform auxiliary braking of the vehicle 1. In one embodiment, the plurality of auxiliary brake devices 6 include two or more types of auxiliary brake devices such as an exhaust brake, a brake pressurizing device, an engine retarder, and a transmission retarder. In the embodiment shown in FIG. 1, the plurality of auxiliary brake devices 6 include an engine retarder 7 and a transmission retarder 8.

The engine retarder 7 is an auxiliary brake device that applies braking force to the vehicle 1 by forcibly opening an exhaust valve during a compression stroke of the engine and releasing compression pressure of the engine. The braking force applied to the vehicle 1 from the engine retarder 7 can be switched to multiple levels. For example, the operating mode of the engine retarder 7 can be switched into two stages: a weak mode and a strong mode. When the engine retarder 7 operates in the weak mode, a relatively small braking force is applied to the vehicle 1, and when the engine retarder 7 operates in the strong mode, a relatively large braking force is applied to the vehicle 1. . That is, the engine retarder 7 can perform a first auxiliary brake operation and a second auxiliary brake operation that applies a larger braking force to the vehicle 1 than the first auxiliary brake operation.

The transmission retarder 8 is a device that applies a frictional force to the output shaft of the transmission of the vehicle 1 to provide braking force to the vehicle 1. The braking force applied to the vehicle 1 from the transmission retarder 8 can be switched in multiple stages. For example, the operation mode of the transmission retarder 8 can be switched into two stages: a weak mode and a strong mode. When the transmission retarder 8 operates in the weak mode, a relatively small braking force is applied to the vehicle 1, and when the transmission retarder 8 operates in the strong mode, a relatively large braking force is applied to the vehicle 1. .

Transmission retarder 8 provides greater braking force to vehicle 1 than engine retarder 7. For example, the braking force of the transmission retarder 8 operating in the weak mode is greater than the braking force of the engine retarder 7 operating in the strong mode. That is, the transmission retarder 8 performs a third auxiliary brake operation that applies a larger braking force to the vehicle 1 than the second auxiliary brake operation, and a fourth auxiliary brake operation that applies a larger braking force to the vehicle 1 than the third auxiliary brake operation. It is possible to perform brake operations.

The operations of the engine retarder 7 and the transmission retarder 8 are controlled by a vehicle control device 10. For example, by sending a control signal from the vehicle control device 10 to the engine retarder 7 and the transmission retarder 8, the engine retarder 7 and the transmission retarder 8 are activated, deactivated, and the operation mode is switched.

The vehicle control device 10 is an electronic control unit that includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), a CAN (Controller Area Network) communication circuit, and the like. The vehicle control device 10 is connected to a communication network using, for example, a CAN communication circuit, and is communicably connected to each component of the vehicle 1. For example, the vehicle control device 10 operates a CAN communication circuit to input and output data based on a signal output by the CPU, stores the data in the RAM, loads a program stored in the ROM into the RAM, By executing the programs loaded into the RAM, various functions described below are realized. Vehicle control device 10 may be composed of a plurality of electronic control units. Vehicle control device 10

As shown in FIG. 1, the vehicle control device 10 includes, as a functional configuration, a vehicle information acquisition section 11, a deceleration target detection section 12, a target deceleration acquisition section 13, a predicted deceleration calculation section 14, and a control section 15. There is.

The vehicle information acquisition unit 11 acquires information regarding the vehicle 1 (hereinafter referred to as "vehicle information"). For example, the vehicle information acquisition unit 11 acquires the vehicle speed and vehicle weight measured by the internal sensor 3. That is, the vehicle information acquisition unit 11 functions as a vehicle speed acquisition unit that acquires vehicle speed and a vehicle weight acquisition unit that acquires vehicle weight. Furthermore, the vehicle information acquisition unit 11 acquires the engine speed, transmission gear stage (hereinafter referred to as "gear ratio"), differential gear gear ratio (hereinafter referred to as "differential ratio"), total gear ratio (transmission gear (the product of the differential gear ratio and the gear ratio of the differential gear), the front projected area of the vehicle 1, the road gradient, etc. are acquired as vehicle information.

The deceleration target detection unit 12 detects a deceleration target in front of the own vehicle based on the detection result of the external sensor 2. The deceleration target is the target of deceleration support control. Targets for deceleration include curves, traffic lights, stop lines, and preceding vehicles. The deceleration support control is control to decelerate the vehicle 1 to the target vehicle speed. In principle, the target vehicle speed is set according to the type of object.

The deceleration target detection unit 12 detects a deceleration target by performing pattern matching using pre-stored image patterns for each type of deceleration target, based on a captured image of the front of the host vehicle captured by a camera, for example. do. For example, when the deceleration target is a stop line, the deceleration target detection unit 12 recognizes the position of the stop line by extracting a white line extending in the width direction of the road using a well-known image recognition technology. . Note that the deceleration target detection unit 12 may detect a deceleration target based on the position of an object detected by a radar sensor.

The target deceleration acquisition unit 13 acquires the target deceleration of the vehicle 1. For example, the target deceleration acquisition unit 13 sets the target deceleration based on the speed of the vehicle 1, the distance from the vehicle 1 to the deceleration target, and the target speed. For example, if the deceleration target is a stop line, the target speed before the stop line is 0 km/h. Therefore, the target deceleration acquisition unit 13 sets a target deceleration so that the vehicle 1 can stop before the stop line. Note that deceleration indicates negative acceleration. Therefore, a large deceleration means a small acceleration.

The predicted deceleration calculation unit 14 calculates a predicted value of the deceleration of the vehicle 1 (hereinafter referred to as "predicted deceleration"). For example, the predicted deceleration calculation unit 14 calculates the predicted deceleration based on the deceleration caused by the running resistance of the vehicle 1 and the deceleration caused by the braking force of the plurality of auxiliary brake devices 6. The running resistance of the vehicle 1 includes air resistance, rolling resistance, gradient resistance, transmission inertia moment, etc. of the vehicle 1.

The deceleration caused by air resistance is calculated based on, for example, the overall projected area of the vehicle 1, the vehicle speed, and the vehicle weight. The deceleration caused by rolling resistance is calculated based on, for example, the rolling resistance coefficient and the road slope. The deceleration caused by gradient resistance is calculated based on the road gradient, for example. The transmission moment of inertia is calculated based on, for example, the gear stage of the transmission, the total gear ratio, the tire radius, and the vehicle weight.

Further, the predicted deceleration calculation unit 14 predicts the deceleration caused by the braking forces of the plurality of auxiliary brake devices 6. For example, the storage unit of the vehicle control device 10 stores first deceleration data indicating the relationship between vehicle speed, vehicle weight, and deceleration for each operating mode of the engine retarder 7. The predicted deceleration calculation unit 14 calculates the braking force generated by the operation of the engine retarder 7 by extracting the braking force corresponding to the vehicle speed and vehicle weight acquired by the vehicle information acquisition unit 11 from the first deceleration data. get. Note that the predicted deceleration calculation unit 14 calculates the engine retarder 7 based on the engine speed, the differential ratio, the gear ratio, the tire radius of the vehicle 1, and the vehicle weight, without using the first deceleration data. The deceleration caused by the braking force may be calculated and obtained.

Further, the storage unit of the vehicle control device 10 stores second deceleration data indicating the relationship between the vehicle speed, the vehicle weight, and the deceleration of the transmission retarder 8 for each operating mode. The predicted deceleration calculation unit 14 calculates the braking force generated by the operation of the transmission retarder 8 by extracting the braking force corresponding to the vehicle speed and vehicle weight acquired by the vehicle information acquisition unit 11 from the second deceleration data. get. The predicted deceleration calculation unit 14 outputs the sum of the deceleration caused by the running resistance of the vehicle 1 determined as described above and the deceleration caused by the braking forces of the plurality of auxiliary brake devices 6 as the predicted deceleration.

The control unit 15 controls the operation of the main brake device 5 and the plurality of auxiliary brake devices 6 based on the target deceleration and the predicted deceleration. For example, the control unit 15 sends control signals to the main brake device 5, the engine retarder 7, and the transmission retarder 8, and activates or deactivates the main brake device 5, activates or deactivates the engine retarder 7, and activates or deactivates the transmission retarder. Controls the activation or deactivation of 8. Further, the control unit 15 switches the operation mode (weak mode or strong mode) of the engine retarder 7 and the transmission retarder 8.

The functions of the vehicle control device 10 will be explained in more detail with reference to FIGS. 2 and 3. 2 and 3 are flowcharts showing the flow of processing executed by the vehicle control device 10.

As shown in FIG. 2, first, the vehicle information acquisition unit 11 of the vehicle control device 10 acquires vehicle information of the vehicle 1 (step ST1). Specifically, the vehicle information acquisition unit 11 acquires information regarding vehicle speed, vehicle weight, road gradient, total gear ratio, tire radius, engine rotation speed, and transmission gear stage as vehicle information.

Next, the target deceleration acquisition unit 13 acquires the target deceleration. For example, when a stop line exists in front of the vehicle 1, the target deceleration acquisition unit 13 sets a target deceleration that allows the vehicle 1 to stop before the stop line.

Next, the predicted deceleration calculation unit 14 calculates a first predicted deceleration that is a predicted value of the deceleration when the operation of the main brake device 5 and the plurality of auxiliary brake devices 6 is stopped (step ST3). That is, the first predicted deceleration is a predicted value of the deceleration of the vehicle 1 when the first auxiliary brake operation and the second auxiliary brake operation are not performed. For example, the predicted deceleration calculation unit 14 sets the sum of the deceleration caused by running resistance (air resistance, rolling resistance, and gradient resistance) of the vehicle 1 and the deceleration caused by the engine brake of the vehicle 1 as the first predicted deceleration. calculate.

Next, the control unit 15 determines whether or not a first operating condition, which is a condition for operating the engine retarder 7 in the weak mode, is satisfied (step ST4). For example, the control unit 15 determines that the first operating condition is satisfied when the vehicle speed is equal to or higher than the first speed (first threshold) and the target deceleration is greater than the first predicted deceleration. The first speed is a preset speed, and is, for example, 8 km/h.

When the first operating condition is satisfied, the control unit 15 controls the engine retarder 7 to operate the engine retarder 7 in the weak mode (step ST5). As described above, when the vehicle speed is equal to or higher than the first speed and it is predicted that the deceleration when the operation of the engine retarder 7 and the transmission retarder 8 is stopped will not reach the target deceleration, the engine retarder 7 is operated in weak mode.

Next, the predicted deceleration calculation unit 14 calculates a second predicted deceleration, which is a predicted value of the deceleration when the engine retarder 7 is operated in the weak mode and the operation of the main brake device 5 and the transmission retarder 8 is stopped. Calculate (step ST6). For example, the predicted deceleration calculation unit 14 calculates the sum of the deceleration caused by the running resistance of the vehicle 1, the deceleration caused by the engine brake of the vehicle 1, and the deceleration caused by the engine retarder 7 operating in the weak mode. 2 Calculated as predicted deceleration. At this time, the predicted deceleration calculation unit 14 extracts the deceleration corresponding to the vehicle speed and vehicle weight acquired by the vehicle information acquisition unit 11 from the first deceleration data, so that the engine retarder operating in the weak mode Obtain the deceleration caused by 7.

Next, the control unit 15 determines whether or not a second operating condition, which is a condition for operating the engine retarder 7 in the strong mode, is satisfied (step ST7). For example, the control unit 15 determines that the second operating condition is satisfied when the vehicle speed is the second speed (second threshold) and the target deceleration is larger than the second predicted deceleration. The second speed is higher than the first speed, for example 10 km/h.

When the second operating condition is satisfied, the control unit 15 controls the engine retarder 7 to operate the engine retarder 7 in the strong mode (step ST8). As described above, when the vehicle speed is equal to or higher than the first speed and it is predicted that the deceleration when the engine retarder 7 is operated in the weak mode will not reach the target deceleration, the engine retarder 7 is activated in the strong mode. is activated.

Next, the predicted deceleration calculating unit 14 calculates a third predicted deceleration, which is a predicted value of the deceleration when the engine retarder 7 is operated in the strong mode and the operation of the main brake device 5 and the transmission retarder 8 is stopped. Calculate (step ST9). For example, the predicted deceleration calculation unit 14 sets the sum of the deceleration caused by the running resistance of the vehicle 1, the deceleration caused by the engine brake, and the deceleration caused by the engine retarder 7 operating in the strong mode as the third predicted deceleration. calculate.

Next, as shown in FIG. 3, the control unit 15 determines whether or not a third operating condition, which is a condition for operating the transmission retarder 8 in the weak mode, is satisfied (step ST10). For example, the control unit 15 determines that the third operating condition is satisfied when the vehicle speed is equal to or higher than the third speed (third threshold) and the target deceleration is greater than the third predicted deceleration. The third speed is higher than the second speed, for example 20 km/h.

When the third operating condition is satisfied, the control unit 15 controls the transmission retarder 8 to operate the transmission retarder 8 in the weak mode (step ST11). As described above, when the vehicle speed is equal to or higher than the third speed and it is predicted that the deceleration when the engine retarder 7 is operated in the strong mode will not reach the target deceleration, the engine retarder 7 is activated in the strong mode. The transmission retarder 8 is operated in the weak mode.

Next, the predicted deceleration calculation unit 14 calculates a predicted value of the deceleration when the operation of the main brake device 5 is stopped, the engine retarder 7 is operated in a strong mode, and the transmission retarder 8 is operated in a weak mode. A fourth predicted deceleration is calculated (step ST12). For example, the predicted deceleration calculation unit 14 calculates the deceleration caused by the running resistance of the vehicle 1, the deceleration caused by engine braking, the deceleration caused by the engine retarder 7 operating in the strong mode, and the deceleration caused by the transmission retarder 7 operating in the weak mode. 8 is calculated as the fourth predicted deceleration. At this time, the predicted deceleration calculation unit 14 extracts the deceleration corresponding to the vehicle speed and vehicle weight acquired by the vehicle information acquisition unit 11 from the second deceleration data, so that the transmission retarder operating in the weak mode Obtain the deceleration caused by 8.

Next, the control unit 15 determines whether a fourth operating condition, which is a condition for operating the transmission retarder 8 in the strong mode, is satisfied (step ST13). For example, the control unit 15 determines that the vehicle speed is equal to or higher than a fourth speed (fourth threshold), the vehicle weight is equal to or higher than a predetermined weight (fifth threshold), and the target deceleration is lower than the fourth predicted deceleration. When it is large, it is determined that the fourth operating condition is satisfied. The fourth speed is higher than the second speed, for example 20 km/h. The predetermined weight is a preset weight, for example, 10 tons.

When the fourth operating condition is satisfied, the control unit 15 controls the transmission retarder 8 to operate the transmission retarder 8 in the strong mode (step ST14). As mentioned above, it is predicted that the vehicle speed is the fourth speed or higher, the vehicle speed is the predetermined weight or higher, and the deceleration when the transmission retarder 8 is operated in the weak mode will not reach the target deceleration. When the engine retarder 7 is activated, the engine retarder 7 is operated in a strong mode, and the transmission retarder 8 is operated in a strong mode.

Next, the predicted deceleration calculation unit 14 calculates a fifth predicted deceleration, which is a predicted value of the deceleration when the operation of the main brake device 5 is stopped and the engine retarder 7 and the transmission retarder 8 are operated in the strong mode. Calculate (step ST15). For example, the predicted deceleration calculation unit 14 calculates the deceleration caused by the running resistance of the vehicle 1, the deceleration caused by engine braking, the deceleration caused by the engine retarder 7 operating in the strong mode, and the deceleration caused by the transmission retarder 7 operating in the strong mode. 8 is calculated as the fifth predicted deceleration.

Next, the control unit 15 determines whether or not the fifth operating condition, which is a condition for operating the main brake device 5, is satisfied (step ST16). For example, the control unit 15 determines that the fifth operating condition is satisfied when the target deceleration is greater than the fifth predicted deceleration.

When the fifth operating condition is satisfied, the control unit 15 operates the main brake device 5 (step ST17). At this time, the control unit 15 controls the main brake device 5 so that a deceleration corresponding to the deficient amount is generated according to the difference between the target deceleration and the fifth predicted deceleration. As described above, the main brake device 5 is operated when it is predicted that the deceleration when the engine retarder 7 and the transmission retarder 8 are operated in the strong mode will not reach the target deceleration, so the main brake device 5 Excessive use of the main brake device 5 is suppressed, and the life of the main brake device 5 is extended.

Further, if it is determined in steps ST4, ST7, ST10, and ST13 that the first to fourth operating conditions are not satisfied, the control unit 15 controls the sixth operating condition, which is a condition for operating the main brake device 5. It is determined whether the conditions are satisfied (step ST18). For example, the control unit 15 determines that the sixth operating condition is satisfied when the vehicle speed is the fifth speed or higher and the target deceleration is the predetermined deceleration or higher. The fifth speed is a speed lower than the first speed, for example, 2 km/h. The predetermined deceleration is, for example, −0.05 mm/s ² . In one embodiment, the control unit 15 determines that the sixth operating condition is satisfied when the vehicle speed is equal to or higher than the second speed and the target deceleration is greater than the deceleration caused by the running resistance of the vehicle 1. You may.

When the sixth operating condition is satisfied, the control unit 15 operates the main brake device 5 (step ST19).

The vehicle control device 10 described above calculates a predicted value of deceleration, compares the predicted value of deceleration with the target deceleration, and controls the operation of a plurality of auxiliary brake devices. The difference between the actual deceleration and the actual deceleration can be reduced. Further, the engine retarder 7 and the transmission retarder 8 are difficult to control precisely, unlike the main brake. Therefore, for example, if the engine retarder 7 and the transmission retarder 8 are activated when the vehicle speed is low, the vehicle 1 may be rapidly decelerated and the ride comfort for the occupants may deteriorate. On the other hand, in the vehicle control device 10, since the engine retarder 7 and the transmission retarder 8 are operated when the vehicle speed is above a certain value, it is possible to suppress deterioration of ride comfort.

Although vehicle control devices according to various embodiments have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made without changing the gist of the invention. That is, it should be noted that the above-described embodiments are for illustrative purposes only and do not limit the scope of the present invention. Note that the various embodiments described above can be combined within a consistent range.

DESCRIPTION OF SYMBOLS 1... Vehicle, 5... Main brake device, 6... Auxiliary brake device, 10... Vehicle control device, 13... Target deceleration acquisition part, 14... Predicted deceleration calculation part, 15... Control part.

Claims (3)

A vehicle control device that controls the operation of a main brake that applies braking force to a vehicle and a plurality of auxiliary brake devices,
a vehicle speed acquisition unit that acquires the speed of the vehicle;
a target deceleration acquisition unit that acquires a target deceleration of the vehicle;
a predicted deceleration calculation unit that calculates a predicted value of deceleration of the vehicle;
a control unit that controls operation of the main brake and the plurality of auxiliary brakes based on a predicted value of deceleration of the vehicle;
Equipped with
The plurality of auxiliary brake devices are capable of performing a first auxiliary brake operation and a second auxiliary brake operation that applies a larger braking force to the vehicle than the first auxiliary brake operation,
The predicted deceleration calculation unit calculates a first predicted deceleration that is a predicted value of the deceleration of the vehicle when the first auxiliary brake operation and the second auxiliary brake operation are not performed, and the first auxiliary brake operation. is performed and a second predicted deceleration is a predicted value of the deceleration of the vehicle when the second auxiliary brake operation is not performed,
The control unit is configured to perform the first auxiliary brake operation when the speed of the vehicle is equal to or higher than a first threshold and the target deceleration is larger than the first predicted deceleration, and the speed of the vehicle is the plurality of auxiliary brake devices such that the second auxiliary brake operation is executed when the target deceleration is greater than or equal to a second threshold that is larger than the first threshold, and the second predicted deceleration is greater than the second predicted deceleration; control,
Vehicle control device. Further comprising a vehicle weight acquisition unit that acquires the weight of the vehicle,
The plurality of auxiliary brake devices perform a third auxiliary brake operation that applies a larger braking force to the vehicle than the second auxiliary brake operation, and a third auxiliary brake operation that applies a larger braking force to the vehicle than the third auxiliary brake operation. A fourth auxiliary brake operation can be further performed,
The predicted deceleration calculation unit calculates the deceleration of the vehicle when the first auxiliary brake operation and the second auxiliary brake operation are performed and the third auxiliary brake operation and the fourth auxiliary brake operation are not performed. A third predicted deceleration, which is a predicted value, and a state of the vehicle when the first auxiliary brake operation, the second auxiliary brake operation, and the third auxiliary brake operation are performed, and the fourth auxiliary brake operation is not performed. further calculating a fourth predicted deceleration, which is a predicted value of the deceleration;
The control unit executes the third auxiliary brake operation when the speed of the vehicle is at least a third threshold that is larger than the second threshold, and the target deceleration is larger than the third predicted deceleration. and the speed of the vehicle is greater than or equal to a fourth threshold that is greater than the second threshold, the weight of the vehicle is greater than a fifth threshold, and the target deceleration is greater than the fourth predicted deceleration. The vehicle control device according to claim 1 , wherein the plurality of auxiliary brake devices are controlled so that the fourth auxiliary brake operation is executed at a time when the fourth auxiliary brake operation is performed. The predicted deceleration calculation unit is configured to calculate a predicted deceleration of the vehicle when the first auxiliary brake operation, the second auxiliary brake operation, the third auxiliary brake operation, and the fourth auxiliary brake operation are performed. Further calculate a certain fifth predicted deceleration,
The vehicle control device according to claim 2, wherein the control unit operates the main brake when the target deceleration is larger than the fifth predicted deceleration.

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