JP2001238309A - Vehicle drive support apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicle drive support apparatus, ensuring that the speed does not exceed the limit during the drive of vehicle and supports the driving at the speed as close as possible to the speed limit. SOLUTION: In a vehicle drive support apparatus (1.01) for receiving the input of the current speed (1.11) of the vehicle, current position (1.12), speed limit (1.13) and operation instruction by a driver (1.14) and to output a instruction given to a vehicle drive system of the vehicle, there are provided a maximum approach instruction selecting means (1.02) for calculating a forecasted locus from the current position and current speed, for a plurality of assumed instructions at a future point at a constant time and outputting the assumed instruction when the forecast speed at the forecasted locus does not exceed the speed limit and is most approximated thereto as the maximum approach instruction (1.16) and outputting a low order instruction among the operation instruction and maximum approach instruction to be compared as the vehicle instruction (1.15).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle traveling control system in a transportation system such as a railway train, and more particularly to a vehicle driving support device mounted on a vehicle to assist a driver in driving the vehicle.

[0002]

2. Description of the Related Art Driving assistance devices that assist a driver in driving a vehicle include those that partially perform the driving operation.
There are many forms, even those intended for full automation. As a device that partially assists, there is a constant speed control device for the purpose of keeping the running speed of the vehicle constant. This is a control device that exists inside the drive system of the vehicle and keeps the rotation speed of the motor constant.The control device can cancel the instantaneous deviation of the actual rotation speed from the specified rotation speed by feedback control. It is essence. As the driver's operation, the driver reaches the desired speed by the driver's operation, and then performs the above-described constant speed control to perform the constant speed traveling at the specified speed. A method of realizing such an apparatus is described in Japanese Patent Application Laid-Open No. 10-203198 as a known example. In addition, an automatic driving device may be used as a device that is intended to be fully automated. This exists in a control system that controls the drive system of the vehicle, and sequentially selects control commands for travel control so that the vehicle travels at a specified target speed and outputs the control commands to the drive system. The target speed is given in the form of a constant speed or a running curve showing the speed movement from the departure point to the arrival point. As a driver's operation, there is no need to directly engage in driving while driving. Such a device is disclosed in, for example, Japanese Patent Application Laid-Open No. H07-067217.
The publication discloses an implementation method.

[0003]

In recent years, in driving a vehicle, an allowable speed range below a speed limit is used to the maximum in order to shorten the running time and to enhance the ability to recover an operation plan (diamond) when the operation is disrupted. As a result, there is a demand for flexible driving that can respond flexibly to driving conditions. On the other hand, there is a demand for high-quality driving that eliminates the operation of security brakes due to unnecessary excess of the speed limit and improves ride comfort and energy saving. However, it is difficult for the above-described conventional technology to stably perform an operation that does not exceed the speed limit and that is extremely close to the speed limit. In the constant speed control device disclosed in Japanese Patent Application Laid-Open No. Hei 10-203198, control is performed after detecting the influence on the speed of a change in route conditions, so that the speed limit is likely to be exceeded due to a control delay. .
On the other hand, in the automatic driving apparatus disclosed in Japanese Patent Application Laid-Open No. 07-067217, the allowable speed cannot be fully utilized because the target speed is a speed obtained by subtracting a certain speed from the speed limit. In addition, in each case, the actual speed is allowed to fluctuate up and down with respect to the designated speed. As long as this method is used, it is not possible to reliably prevent the speed from exceeding the speed limit.

[0004] It is an object of the present invention to provide a driving support system for a vehicle, which ensures that the speed limit is not exceeded in driving the vehicle, and which assists driving such that the speed limit is reduced.

[0005]

In order to solve the above-mentioned problems, a vehicle speed command, which is provided to a drive system of a vehicle body of a vehicle, receives input of a current speed, a current position, a speed limit, and an operation command from a driver. In the vehicle driving support device that outputs the current position, a predicted trajectory corresponding to a plurality of assumed commands at a future point in time at a certain time from the current position is calculated, and the predicted speed of the predicted trajectory does not exceed the speed limit, And,
A maximum approach command selecting means for outputting an assumed command in the case of closest approach as a maximum approach command, and a vehicle command selecting means for comparing an operation command and a maximum approach command and setting any lower command as a body command and outputting the command; Have.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a configuration of a vehicle driving support device according to an embodiment of the present invention. As shown in FIG. 1, the driving assistance device (1.01) of the present embodiment has a current vehicle speed (1.11), a current vehicle position (1.12), and a vehicle speed. When this value is reached, the speed limit (1.13) at which the security brake is activated, and the input of an operation command (1.14) by the driver are accepted, and a vehicle command issued to the drive system of the vehicle to actually control the vehicle. (1.1
5) is output. The driving support device (1.01) includes a maximum approach command selecting means (1.02) as an internal means. The maximum approach command selecting means (1.02) is configured to output the current speed (1.11) input to the driving support device (1.01),
The input of the current position (1.12) and the speed limit (1.13) is received, and the maximum approach command (1.16) is output. The maximum approach command (1.16) is a control such that when it is commanded to the drive system of the vehicle body at this time, the speed of the vehicle does not exceed the speed limit and can reach the speed closest to the speed limit. Directive. In addition, a driving support device (1.01)
Is a vehicle body command selecting means (1.0
3) is provided. The vehicle body command selecting means (1.03) is input from the maximum approach command (1.16) output from the maximum approach command selecting means (1.02) and the driving support device (1.01) from outside. Receiving an operation command (1.14),
The vehicle command (1.15) is output to the outside of the driving support device (1.01). The driving command according to the operation command (1.14) is applied as it is to the vehicle body command (1.15) as long as there is no risk of exceeding the speed limit. Another control command is applied that does not exceed the speed.

Hereinafter, a method of realizing the internal means of the driving support device according to the present embodiment will be described in detail. FIG. 2 shows the internal configuration of the maximum approach command selecting means (1.02). The maximum approach command selection means (1.01) includes, as its internal means, a predicted speed calculation means (2.02) and a maximum approach command determination means (2.03). Predicted speed calculation means (2.
02) receives the current speed (1.11) and the current position (1.12) inputted to the maximum approach command selecting means (1.02), and outputs the predicted speed (2.15). The predicted speed (2.15) refers to a future speed predicted for each selectable control command (assumed command) assumed for the vehicle at the present time when the command is sent to the drive system of the vehicle body.
Therefore, the predicted speed (2.15) has a value individually for each assumed command, and exists as many as the number of assumed commands. The maximum approach command determining means (2.03) includes a predicted speed (2.15) from the predicted speed calculating means (2.02) and a speed limit (1. 1
3) is accepted and the maximum approach command (1.16) is output.

FIG. 3 shows the internal configuration of the predicted speed calculation means (2.02). The predicted speed calculation means (2.02) includes, as its internal means, predicted trajectory calculation means (3.02)
A route condition data holding unit (3.03) in which information on track characteristics of a traveling route of a vehicle is integrated, and a vehicle condition data holding unit (3.3) in which information on characteristics of a vehicle body is integrated.
04). The predicted trajectory calculation means (3.02) stores the current speed (1.11) and the current position (1.12) inputted to the predicted speed calculation means (2.02) in the route condition data holding means (3.03). ) To route condition data (3.1
4), the vehicle condition data (3.15) is received from the vehicle condition data holding means (3.04), and the predicted speed (2.1) is received.
5) is output. Note that the route condition data (3.14) includes the range and the value of the slope with respect to the slope of the route. Further, the vehicle condition data (3.15) includes a speed-acceleration / deceleration characteristic corresponding to each assumed command for the vehicle body. The speed-acceleration / deceleration characteristic corresponding to the assumed command indicates the acceleration / deceleration that appears in the vehicle motion when the vehicle is running at a certain speed and the output of the assumed command to the drive system of the vehicle body is assumed.

FIG. 4 shows the overall flow of the processing of the predicted trajectory calculation means (3.02). In FIG. 4, in step (4.01), step (4.0) is performed for each assumed command Ci indicated in the vehicle condition data (3.15).
2) is repeatedly executed. In step (4.02), for a certain assumed command Ci, a certain estimated time T [s]
The subsequent speed Vi is calculated. Vi obtained here is the predicted speed Vi related to the assumed command Ci. Note that the predicted time T
Is preset in the predicted trajectory calculation means (3.02). Lastly, in step (4.03), the predicted speed Vi related to each of the assumed commands Ci that have been obtained is calculated by the predicted speed calculating means (2.0) provided with the predicted trajectory calculating means (3.02).
Output to the external maximum approach command determination means (2.03) of 2).

FIG. 5 shows a specific processing flow of the step (4.02) with respect to the processing flow of the predicted trajectory calculation means (3.02). In step (5.01),
The current speed Vo [km / h] and the current position So [m] input to the predicted trajectory calculation means (3.02) are recognized.
In step (5.02), the processing variable V [k
m / h], position S [m], and time t [s]
Initialize with o, So, 0. In step (5.03), the following steps (5.04) to step (5.09) are repeatedly executed when the time t is smaller than the predicted time T. In step (5.04), the speed V
Acceleration / deceleration characteristic a [km / h / s] of assumed command C
From the vehicle condition data (3.15). In step (5.05), the resistance characteristic R at the position S and the velocity V is calculated.
[Km / h / s] is obtained. The resistance characteristic R includes a gradient resistance Rg [kg weight / ton] due to the gradient at the position S, a running resistance Rr [ kg weight / ton]. That is, the gradient resistance Rg is obtained by converting the gradient G [per mil] at the position S into the route condition data (3.1).
4) and calculated according to the following equation: Rg = G The running resistance Rr is obtained by acquiring the section type at the position S from the route condition data (3.14), and calculating the running resistance coefficients A0, A1, and A2 corresponding to the section type in the vehicle condition data (3.1).
5), and calculate the velocity V according to the following equation. Rr = A0 + A1 × V + A2 × V × V The resistance characteristic R is calculated from the gradient resistance Rg and the running resistance Rr according to the following equation. R = (Rg + Rr) /28.33 Here, 28.33 represents a unit conversion constant. In step (5.06), the future speed Vn after the time step dt [s] is obtained from the speed V, the acceleration / deceleration characteristics a, and the resistance characteristics R.
[Km / h] is calculated according to the following equation. Note that the time step dt is set in advance in the predicted trajectory calculation means (3.02). Vn = V + (a−R) × dt In the step (5.07), the future position Sn [m] after the time step dt is calculated from the position S, the speed V, and the future speed Vn according to the following equation. Sn = S + (V + Vn) × dt / 7.2 Here, 7.2 represents a unit conversion constant. In step (5.08), the position S and the speed V are updated to the values of the future speed Vn and the future position Sn, respectively. In step (5.09), a time step dt is set for time t.
Is added and updated. In step (5.10), the speed V obtained as a result of the above processing is set as the output of the predicted trajectory calculation means (3.02). That is, the maximum approach command determining means (2.0
Output to 3). As described above, the predicted speed relating to each assumed command output from the predicted speed calculation means (2.02) is used by the maximum approach command determination means (2.03) to determine the maximum approach command (1.16).

FIG. 6 shows the maximum approach command determining means (2.0
The flow of the process 3) is shown. In step (6.01),
The speed limit Vl input to the maximum approach command selection means (1.02) including the maximum approach command determination means (2.03) is obtained. In step (6.02), a predicted speed Vi for each assumed command Ci input to the maximum approach command determining means (2.03) is obtained. In step (6.03),
The processing variable dVmin is initialized with 1000. Further, the processing variable Cmax is initialized to the lowest one of the assumed commands (the value of the corresponding acceleration / deceleration characteristic is the lowest). In step (6.04), for each assumed command Ci,
From the following step (6.05) to step (6.08)
Is repeatedly executed. In step (6.05), the process returns to step (6.04) if Vi ≧ V1 for the predicted speed Vi and the speed limit Vl, and otherwise proceeds to step (6.06). In step (6.06), the difference Vl-Vi between the speed limit Vl and the predicted speed Vi is set in the processing variable dVi. In step (6.07),
For the processing variables dVi and dVmin, dVi ≧ dVm
In the case of in, the process returns to step (6.04), and otherwise, the process proceeds to step (6.08). In step (6.08), the processing variables dVmin and Cmax are updated to the values of dVi and Ci, respectively. In step (6.09), the processing variable Cmax obtained as a result of the above processing is set as the output of the maximum approach command determination means (2.03). That is, the maximum approach command determining means (2.03)
Is the maximum approach command (1.16) which is the output of the maximum approach command selection means (1.02) provided with.

Next, the processing of the vehicle body command selecting means (1.03) provided in the driving support device (1.01) will be described in detail. As described above, the vehicle body command selecting means (1.0
3) receives the maximum approach command (1.16) from the maximum approach command selection means (1.02) and the operation command (1.14) from outside the driving support device (1.01), and receives the vehicle body command (1). .15) to the outside of the driving support device (1.01). The vehicle body command (1.15) is selected based on the maximum approach command (1.16) and the operation command (1.14).
If the operation command (1.14) is within the above-mentioned range in the range of the control command having the maximum approach command (1.16) as the upper limit, the operation command (1.14) is adopted, and outside the above-mentioned range, the operation command (1.14) is adopted. If so, the highest approach command (1.16) is adopted. That is, when operation command <maximum approach command: body command = operation command When operation command ≧ maximum approach command: vehicle command = maximum approach command

FIG. 7 shows a processing flow of the vehicle body command selecting means (1.03). In FIG. 7, step (7.0)
In 1), the maximum approach command and the operation command are acquired. At step (7.02), the operation command is compared with the maximum approach command, and the setting process of the vehicle body command according to the comparison result is the operation command ≧
In the case of the maximum approach command, the process is performed in step (7.03), and in the case of the operation command <the maximum approach command, the process is performed in step (7.04). The set vehicle command is sent to step (7.05).
Output from the vehicle body command selecting means (1.03).

FIG. 8 and FIG. 9 show examples of traveling by the driving assistance apparatus according to the above-described embodiment. FIG. 8 shows a state of running with time and selecting a control command. First, the driving situations indicated by (8.01) to (8.07) will be described. At the present time (8.02), which is the tip of the actual trajectory (8.01), the vehicle has the speed limit (8.0).
Aiming for acceleration toward 3). At this point, the operation command by the driver is assumed to be C1. On the other hand, the driving support device (1.01) calculates predicted trajectories (8.04) to (8.07) for each assumed command in the maximum approach command selecting means (1.02) inside the driving support device (1.01), and calculates the predicted speed thereof. Does not exceed the speed limit (8.03) and recognizes the assumed command (the control command C2 corresponding to the predicted trajectory (8.05)) as the closest approach command (1.16). The driving support device (1.01) compares the operation command C1 and the maximum approach command C2 in the vehicle body command selection means (1.03) inside the driving support device, and does not exceed the speed limit (8.03).
And the intention of the operation command C1, that is, the speed limit (8.03)
A control command C2 is output as a vehicle command that most reflects the intention to accelerate toward. On the other hand, from (8.11) to (8.17) in FIG. 8, the vehicle changes from (8.01) to (8.0).
This shows a running situation at a point in time after the situation shown in 7). The actual trajectory (8.11) indicates a travel reflecting the vehicle body command C2 provided for the travel control in the situations shown from (8.01) to (8.07). At the moment (8.12)
The vehicle continues to aim for positive deceleration (8.13), at which point the driver's operation command continues to be
And The driving support device (1.01) calculates (8.17) from the predicted trajectory (8.14), and assumes an assumed command (prediction) when the vehicle does not exceed the speed limit (8.03) and is closest. Control command C corresponding to locus (8.15)
3) is the maximum approach command (1.16). Then, the speed limit (8.0) is obtained from the operation command C1 and the maximum approach command C3.
The control command C3 is output as a vehicle command that does not exceed 3) and most reflects the acceleration intention of the operation command C1. FIG.
In the traveling shown in FIG. 5, the operation command (1.1
4) is a control command C1 consistently. If this is output to the vehicle body as it is, the speed will eventually reach the speed limit (8.03).
Is inevitable. On the other hand, according to the driving assistance device of the present embodiment, an optimal control command that reflects the acceleration intention of the operation command and does not exceed the speed limit is output to the vehicle body. As a result, for the actual trajectory, a transition that does not exceed the speed limit and is as close as possible is stably realized.

FIG. 9 shows two examples of traveling between stop points by the driving assistance device of this embodiment. First, the traveling indicated by (9.01) to (9.05) will be described. The running result (9.01) indicates an actual trajectory from left to right between the stop points. In relation to the speed limit (9.02),
In section 1 (9.03) after the departure point, the speed limit (9.0
Accelerate toward 2), section 2 between stops (9.04)
In, the vehicle travels stably at the speed limit (9.03), and in section 3 (9.04) before the arrival point, the vehicle decelerates toward the arrival. Regarding the driving operation, in this example, it is assumed that the driver intends to travel between the stop points in the shortest possible time. In section 1 (9.03), the driver's operation command is the maximum acceleration command, but in this case, the vehicle body command (1.15) which is the output from the driving support device (1.01).
Is also the maximum acceleration command. This is because the traveling in the section is a speed separated from the speed limit (9.02) to a lower speed side, so that the operation command (1.14) is directly applied as the vehicle body command (1.15). Subsequent section 2 (9.
04), the operation command (1.14) is still the maximum acceleration command, but in this case, the driving support device (1.01)
The vehicle command (1.15) is generally given by an operation command (1.
14) The highest approach command which is a lower control command.
This is because, when approaching the speed limit (9.12), the driving support device (1.01) issues an operation command (1.
The speed limit (9.0) is reflected while reflecting the acceleration intention of (14).
This is because a lower optimal control command (highest approach command) is set as the vehicle body command (1.15) so as not to exceed 2). Finally, in section 3 (9.05), the driver's operation command (1.14) is a brake command intended to stop at the arrival point, but intends to shift to the low speed side naturally from the speed limit (9.02). Therefore, the vehicle command (1.15) via the driving support device (1.01) is also the same brake command.

Next, the traveling indicated by (9.11) to (9.17) will be described. In the relationship between the actual driving performance (9.11) and the speed limit (9.12), section 1 (9.13)
In the section 2 (9.14), the acceleration toward the speed limit (9.02) and the traveling at a certain speed, and in the section 2 (9.14), the speed limit (9.1)
In the section 3 (9.15), the vehicle was accelerated again to the speed limit (9.02), and there was a certain (position, speed) in section 3 (9.15).
In section 4 (9.16), the vehicle travels again to the speed limit (9.02), and in section 5 (9.17), the vehicle decelerates toward arrival. Regarding the driving operation, in this example, it is assumed that the driver intends to travel between the stop points at a time that allows for some extra time. Section 1
In (9.13), the driver's operation command (1.14) becomes the vehicle body command (1.15) output from the driving support device (1.01) as it is, but this means that the traveling is at the speed limit (9.13). 12) Because it is farther to the lower speed side. In the following section 2 (9.14), in the deceleration portion of the travel, the operation command is a brake command in anticipation of approaching the speed limit (9.12), but at the same time, the travel speed is reduced to the speed limit (9.12). The brake is intended to be loosened, and if commanded to the vehicle as it is, the speed limit (9.1)
2) is exceeded. In this case, the vehicle body command (1.15) from the driving support device (1.01) is generally the highest approach command (1.16) which is a lower control command than the operation command (1.14). Operation command (1.14)
This is a brake having a greater deceleration performance and does not exceed the speed limit (9.12) after a certain time and can be approached most. In addition, in the constant speed portion in the section 2 (9.14), the running speed is reduced to the speed limit (9.12) in order to minimize the increase in the running time due to the low speed limit,
The operation command (1.14) is an acceleration command with a moderate to high acceleration performance. If the command is directly given to the vehicle body, it is a control command that will soon exceed the speed limit (9.12). Also in this case, the vehicle command (1.15) from the driving support device (1.01) generally includes the operation command (1.1).
4) The highest approach command (1.1 which is a lower control command)
6). As described above, in the traveling in the section 2 (9.14), when approaching the speed limit (9.12), the driving support device (1.01) sets the intention of the operation command by the driver, that is, the speed limit (9 .12), while lowering the optimal control command (maximum approach command) to the vehicle body command (1.1) so as not to exceed the speed limit (9.12) while reflecting the speed limit (9.12).
5). Subsequent section 3 (9.15)
In the same manner as in the section 1 (9.13), since the travel is farther to the lower side than the speed limit (9.12), the driver's operation command (1.14) remains unchanged from the vehicle body command (1.15). Becomes In the following section 4 (9.16), section 2 (9.
Similarly to 14), when approaching the speed limit (9.12), the driving assistance device (1.01) reflects the thin intention to the speed limit indicated by the driver's operation command (1.14). Also, a lower optimal control command (maximum approach command) is output as a vehicle body command (1.15) so as not to exceed the speed limit (9.12). The maximum approach command (1.16) in this case is, in particular, a brake having a larger deceleration performance than the operation command (1.14), and does not exceed the speed limit (9.12) after a certain time and the most. It is accessible. Finally, in section 5 (9.17), the driver's operation command (1.14) is a brake command intended to stop at the arrival point, but the driver may naturally leave the speed limit (9.11) in a lower position. Because of the intention, the driving assistance device (1.0
The vehicle command (1.15) via 1) is also the same brake command.

As described above, the driving support apparatus according to the present embodiment respects the driving intention indicated in the driver's operation command as long as the speed limit is not exceeded, while appropriately controlling the vehicle body so as not to exceed the speed limit. Performs the function of optimally adjusting the control command given to the controller. As a result, it is ensured that the speed limit is not exceeded in the driving operation of the vehicle, and the driving to reduce the speed to the speed limit as necessary is supported.

In the driving assistance apparatus according to the present embodiment, an operation command for driving the vehicle is given from the driver as an input. However, application of the present invention is limited to the present embodiment. Not something. As another embodiment, there is a case where an operation command input to the driving support device is given from a driving device characterized by comprehensively performing acceleration and deceleration driving operations in traveling of the vehicle. Even in this case, by applying the present invention, it is ensured that the speed of the vehicle does not exceed the speed limit, and the operation that is reduced to the speed limit is stably realized.

[0019]

As described above, according to the present invention,
In the vehicle operation, it is possible to easily perform the operation in which the speed is reduced to the speed limit. As a result, the allowable speed region below the speed limit can be utilized to the utmost, so that the driving time can be shortened and the operation plan ( Diamond) Recovery ability can be improved. In addition, it is ensured that the speed limit is not exceeded by the control command given to the vehicle body, and unnecessary security brake control is eliminated, so that ride comfort and energy saving can be improved. In addition, the vehicle has flexibility to respond flexibly to driving conditions and can contribute to realizing high-quality driving.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a vehicle driving support device according to an embodiment of the present invention.

FIG. 2 is a configuration diagram of a maximum approach command selecting unit according to the embodiment of the present invention.

FIG. 3 is a configuration diagram of a predicted speed calculation unit according to the embodiment of the present invention.

FIG. 4 is a diagram showing an overall flow of a process of a predicted speed calculation unit according to the embodiment of the present invention;

FIG. 5 is a diagram showing a specific processing flow relating to calculation of a predicted speed in the processing of the predicted speed calculating means according to the embodiment of the present invention.

FIG. 6 is a diagram showing a processing flow of a maximum approach command determining means according to the embodiment of the present invention.

FIG. 7 is a diagram showing a processing flow of a vehicle body command selecting means according to the embodiment of the present invention.

FIG. 8 is a diagram showing a state of a relationship between a command output process and vehicle running according to the embodiment of the present invention.

FIG. 9 shows an overall state between stop points of vehicle running according to the embodiment of the present invention.

[Explanation of symbols]

1.01: driving support device, 1.02: maximum approach command selection means, 1.03: vehicle body command selection means, 2.02: predicted speed calculation means, 2.03: maximum approach command determination means, 3.0
2. Predicted trajectory calculating means 3.03 ... Route condition data holding means 3.04 ... Vehicle condition data holding means

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5H115 PG01 QE08 QE10 QN03 QN06 QN12 SF06 SJ12 SJ13 SL01 SL06 SL07 TB01 TO07 TO09 5H161 BB02 BB06 CC04 CC13 EE07 JJ22 JJ40

Claims (3)

[Claims] 1. A driving assistance system for a vehicle, which receives input of a current speed, a current position, a speed limit, and an operation command from a driver and outputs a body command given to a drive system of a vehicle body of the vehicle. A position, a predicted trajectory corresponding to a plurality of assumed commands at a future point in time at a certain time from the current speed is calculated, and the predicted speed on the predicted trajectory does not exceed the speed limit and is assumed to be the closest. A driving assistance device for a vehicle, wherein the command is recognized as a maximum approach command, and the maximum approach command is output as the vehicle body command when traveling of the vehicle according to the operation command exceeds the speed limit. 2. The vehicle according to claim 1, wherein the traveling of the vehicle according to the operation command does not exceed the speed limit.
A vehicle driving assistance device, wherein the vehicle body command is set at the same level as the operation command. 3. A driving assistance system for a vehicle, which receives an input of a current speed, a current position, a speed limit, and an operation command from a driver and outputs a body command given to a drive system of a vehicle body of the vehicle. A position, a predicted trajectory corresponding to a plurality of assumed commands at a future point in time at a certain time from the current speed is calculated, and the predicted speed on the predicted trajectory does not exceed the speed limit and is assumed to be the closest. A maximum approach command selecting unit that outputs a command as a maximum approach command, and a vehicle command selecting unit that compares the operation command and the maximum approach command and sets a lower command as the vehicle command. Driving support device for a vehicle.