JPH0127972Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a safe driving assist device for vehicles, particularly automobiles equipped with an autotransmission.

Various proposals have been made in the past to ensure safe driving of vehicles, and the present applicant first proposed a practical application in 1983.
One such example is the ``Vehicle Safe Driving Assist Device'' filed under No. 78918. The purpose of this is to automatically control the detection area of dangerous objects from the outputs of direction indicating means, steering means, transmission means, vehicle speed detection means, etc., and to accurately detect dangerous objects to the vehicle. It is something.

However, in the case of such conventional safety driving assist devices, when a dangerous object is detected, most of them use the foot brake device to apply braking to avoid danger. There is a problem in that there is a risk that the braking force will become excessive when something such as the like enters the vehicle.

This idea was made in view of the above circumstances.
When it is determined that braking is necessary based on the outputs from the inter-vehicle distance sensor and vehicle speed sensor, the necessary deceleration is calculated based on the inter-vehicle distance at that time, and is based on the vehicle speed and deceleration stored in advance. There are three stages depending on the deceleration calculated based on the control gator and the vehicle speed at that time: the first stage is engine braking, the second stage is engine braking and exhaust braking is also activated, and the third stage is engine braking and exhaust braking. By controlling vehicle braking in stages by adding a foot brake to the brake, vehicle safety can be achieved by obtaining smooth and appropriate braking force without increasing costs using conventional braking means installed in vehicles. The purpose is to provide driving assistance devices.

Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

FIG. 1 is a block circuit diagram showing one embodiment of the present invention.

In the figure, 2 is a vehicle speed sensor that detects vehicle speed;
4 is an inter-vehicle distance sensor that detects the inter-vehicle distance to the vehicle ahead. Vehicle speed sensor 2 and inter-vehicle distance sensor 4
The outputs from the circuits are respectively input to the discrimination circuit 6, and are also input to the AND gates 8 and 10, respectively. The output from the discrimination circuit 6 is also input to the AND gates 8 and 10. As shown in FIG. 2, the determination circuit 6 determines whether or not the relationship between the two is dangerous based on a graph showing a safe range A, a caution range B, and a danger range C set based on the inter-vehicle distance 1 and the vehicle speed V. When it is in range B and danger range C, it is determined to be dangerous and a danger determination signal is output to AND gates 8 and 10. When the danger determination signal from the determination circuit 6 is input to the AND gates 8 and 10, since the vehicle speed signal and the inter-vehicle distance signal have already been input to the AND gates 8 and 10, respectively,
The outputs of AND gates 8 and 10 rise. The rising output of the AND gate 8 is input to a control circuit 14, which will be described later. Further, the rising output of the AND gate 10 is inputted to an arithmetic circuit 12 which inputs the inter-vehicle distance detection signal from the inter-vehicle distance sensor 4 and calculates the target deceleration necessary for stopping the vehicle safely at that time. An output corresponding to the target deceleration calculated by the circuit 12 based on the amount of change Δ1 of the inter-vehicle distance 1 is input from the calculation circuit 12 to the control circuit 14 .

The control circuit 14 has a memory in which control data based on the deceleration α and the vehicle speed V shown in FIG. According to the vehicle speed signal from the vehicle speed sensor 2 and the output corresponding to the target deceleration from the arithmetic circuit 12, operation command signals for three types of braking means, namely, an engine brake, an exhaust brake, and a foot brake, are appropriately combined and output.

Now, to explain the graph in Figure 3,
This figure shows the relationship between deceleration α and vehicle speed V at each shift, and shows the deceleration α obtained when only engine brake is applied and when both engine brake and exhaust brake are applied at each shift. , are shown by curves D and E, respectively, in relation to the vehicle speed V (3rd and 5th speeds are not shown). That is, when the desired deceleration α is located below curve D (deceleration α ₁ ), only engine braking is applied, and when it is located between curves D and E (deceleration α ₂ ), engine braking is applied. and the exhaust brake is applied, and when the vehicle is located above curve E (deceleration α ₃ ), all of the engine brake, exhaust brake, and foot brake are applied. Therefore, in the control circuit 14, the following determination is made according to the input vehicle speed V signal from the vehicle speed sensor 2 and the target deceleration signal from the arithmetic circuit 12 based on the memorized data. That is, 1) When an exhaust brake is not necessary but an engine brake is necessary (when a relatively small deceleration α ₁ is desired) 2) When a foot brake is not necessary but an engine brake and an exhaust brake are necessary time (moderate deceleration α ₂
3) When all of the engine brake, exhaust brake, and foot brake are required (when it is desired to obtain a relatively large deceleration _α3 ).

Then, in response to the determination result, the drive control circuit 1
5 outputs an engine brake activation signal 16, an exhaust brake activation signal 18, and a footbrake activation signal 20 in stages.

Next, the operation will be explained with reference to the flowchart shown in FIG.

The vehicle speed and inter-vehicle distance are detected by a vehicle speed sensor 2 and an inter-vehicle distance sensor 4 (corresponding to 100 in FIG. 4),
Each output corresponding to this is input to the determination circuit 6, and it is determined whether or not it is safe based on the graph in FIG. 2 (corresponding to 101 in FIG. 4).

As a result of the above determination, if it is determined that the vehicle is safe, the vehicle will continue to run in that state for a while, and the same determination will be made again later. On the other hand, when it is determined that it is unsafe, each AND gate 8 and 10 outputs an output based on the output from the discrimination circuit 6, and the output of the AND gate 10 is used as a trigger to input the inter-vehicle distance from the inter-vehicle distance sensor 4. The calculation circuit 12 calculates the target deceleration based on the detection signal (1 in Fig. 4).
02). The result is input to the control circuit 14 together with the output of the AND gate 8.

Then, in this control circuit 14, using the output of the AND gate 8 as a trigger, the exhaust brake is first applied in accordance with the vehicle speed detection signal input based on the stored control data and the current deceleration based on the target deceleration. It is determined whether or not the exhaust brake is necessary (corresponding to 103 in Figure 4), and if the exhaust brake is not required, the engine brake activation signal 1 is output.
Braking is performed by outputting only 6 (corresponding to 107 in FIG. 4). If the exhaust brake is required, then it is determined whether or not the foot brake is required (corresponding to 104 in Fig. 4), and if the foot brake is not required, the exhaust brake activation signal 18 is activated.
and outputs an engine brake activation signal 16 to perform braking (corresponding to 106 and 107 in FIG. 4). When it is determined that the foot brake is also required, each activation signal 1 of the exhaust brake and engine brake is activated.
In addition to signals 6 and 18, a foot brake activation signal 20 is also output (corresponding to 105 in FIG. 4), and braking is performed using three brakes.

In the above embodiment, the foot brake is automatically operated when the foot brake is necessary based on the judgment result of the control circuit, but this warning can only be issued by a buzzer, lamp, etc. The driver may step on the brake pedal when the brake pedal is heated.

As described above, according to the present invention, when the relationship between the following distance and vehicle speed is dangerous, only the engine brake is activated according to the necessary deceleration and vehicle speed at that time calculated based on the following distance. In addition, it has a three-stage braking control structure that operates both the engine brake and exhaust brake, and when necessary, operates the foot brake in addition to the engine brake and exhaust brake, so it can provide reasonable and appropriate braking force. and the vehicle can be driven safely. Furthermore, since the braking means already installed in the vehicle is used as is without adding a new device, it is highly reliable and inexpensive.

[Brief explanation of drawings]

Fig. 1 is a block circuit diagram showing an embodiment of the present invention, Fig. 2 is a graph showing the relationship between inter-vehicle distance and vehicle speed, Fig. 3 is a graph showing the relationship between deceleration and vehicle speed, and Fig. 4 is a graph showing the relationship between vehicle speed and deceleration. A flowchart of the control method is shown. 2... Vehicle speed sensor, 4... Inter-vehicle distance sensor, 6
...Discrimination circuit, 8, 10...And gate, 12
...Arithmetic circuit, 14...Control circuit.

Claims (1)

[Scope of utility model registration request] A vehicle distance sensor that detects the distance between the vehicle in front of the vehicle ahead, a vehicle speed sensor that detects the vehicle speed, and a determination that determines whether or not the vehicle is dangerous based on the vehicle distance detected by the vehicle distance sensor and the vehicle speed detected by the vehicle speed sensor. a circuit, an arithmetic circuit that calculates deceleration based on the inter-vehicle distance detection signal from the inter-vehicle distance sensor when a danger discrimination signal is input from the discrimination circuit, and control data based on the vehicle speed and deceleration, which are stored in advance. It has a memory, and when a danger signal from the discrimination circuit is input, engine braking is performed in the first stage according to the deceleration calculated by the calculation circuit based on the memorized control data and the vehicle speed detection signal from the vehicle speed sensor. In the second stage, the exhaust brake is activated in addition to the engine brake.
The third stage is characterized by being equipped with a control circuit that controls the operation of three types of braking means, the engine brake, the exhaust brake, and the foot brake, in a stepwise manner so as to operate the foot brake in addition to the engine brake and the exhaust brake. A safe driving aid device for vehicles.