Driving assistance systems

Abstract

In vehicles capable of towing trailers, the system aims to mitigate the decrease in passenger comfort when it mistakenly detects that the vehicle is not coupled to a trailer. [Solution] In the first state, when the vehicle V0 and trailer T are not connected, the driver assistance device 1 assigns a predetermined first speed change rate as the target value for the rate of change of speed when accelerating or decelerating the vehicle, and a predetermined first distance as the target value for the distance between vehicles. In the second state, when the vehicles are connected, the driver assistance device assigns a predetermined second speed change rate that is slower than the first speed change rate as the target value for the rate of change of speed, and a second distance that is greater than the first distance between vehicles as the target value for the distance between vehicles. When the driver assistance device transitions from the second state to the first state while driving, it assigns a value that is slower than the first speed change rate as the target value for the rate of change of speed, and assigns a value that is greater than the first distance between vehicles as the target value for the distance between vehicles.

Description

Technical Field

[0004]

[0001] The present invention relates to a driving support device that supports a driving operation for adjusting the speed of a vehicle capable of towing a trailer.

Background Art

[0002] A driving support device that supports a driving operation for adjusting the speed of a vehicle (host vehicle) capable of towing a trailer has been proposed (see, for example, Patent Document 1 below). The processor of this driving support device (hereinafter referred to as the "conventional device") executes a constant-speed driving process for controlling the driving device and / or braking device of the host vehicle so that the speed (measured value) of the host vehicle matches the speed preset by the driver. However, when there is a preceding vehicle in front of the host vehicle, a vehicle-to-vehicle distance holding process is performed to control the driving device and / or braking device of the host vehicle so that the vehicle-to-vehicle distance between the preceding vehicle and the host vehicle matches a predetermined target vehicle-to-vehicle distance. In the constant-speed driving process and the vehicle-to-vehicle distance holding process, when it is necessary to temporarily accelerate the host vehicle, the processor determines a target value (target acceleration) of the acceleration of the host vehicle and controls the driving device so that the acceleration (measured value) of the host vehicle matches the target acceleration. Here, the processor determines whether a trailer is connected to the host vehicle, and based on the result, determines the target acceleration and the target vehicle-to-vehicle distance. That is, when the processor determines that no trailer is connected to the vehicle, the processor assigns the optimum values in the case where the vehicle weight is relatively small to the target acceleration and the target vehicle-to-vehicle distance, respectively. On the other hand, when the processor determines that a trailer is connected to the host vehicle, the processor assigns the optimum value of the acceleration of the vehicle in the case where the vehicle weight is relatively large to the target acceleration.

Prior Art Documents

Patent Documents

[0005] One of the objectives of the present invention is to provide a driving assistance device that can suppress a decrease in occupant comfort in a vehicle capable of towing a trailer when it is mistakenly determined that the two are not connected.

[0006] To achieve the above objective, the driving assistance device (1) of the present invention is: An automatic speed adjustment process is possible which controls the drive unit (30) and / or brake unit (40) of the vehicle (V0) capable of towing a trailer (T) so as to automatically adjust the speed (sp0) of the vehicle, the process includes controlling the drive unit and / or the brake unit so that the rate of change of speed (α0) when accelerating or decelerating the vehicle matches a predetermined target value (αat, αdt), and when a preceding vehicle (V1) is present in front of the vehicle, the process includes controlling the drive unit and / or the brake unit so that the distance between the vehicle and the preceding vehicle matches a predetermined target value (Dt), and further, a predetermined electronic circuit comprising a first electronic circuit (Ea) provided in the vehicle and a second electronic circuit (Eb) provided in the trailer, and the first electronic circuit and The processor is configured to detect the coupling state between the vehicle and the trailer based on an electrical signal input from an electronic circuit including an electrical signal line (C) connecting to the second electronic circuit, assign a predetermined first speed change rate (αa1, αd1) as the target value of the speed change rate and assign a predetermined first inter-vehicle distance (D1) as the target value of the inter-vehicle distance, and assign a predetermined second speed change rate (αa2, αd2) that is slower than the first speed change rate to the target value of the speed change rate and assign a second inter-vehicle distance (D2) that is greater than the first inter-vehicle distance to the target value of the inter-vehicle distance. The processor is configured such that, in a specific scene in which it detects that the vehicle has transitioned from the second state to the first state based on the electrical signal while it is in motion, it assigns a value that is less gradual than the first rate of change to the target value of the rate of change of speed, and assigns a value that is greater than the first distance between vehicles to the target value of the distance between vehicles.

[0007] It is rare for a trailer to be intentionally detached from a vehicle while it is traveling with the trailer attached. Therefore, when the processor of the driver assistance system according to the present invention detects a transition from the second state (attached state) to the first state (unattached state) during travel, it controls the vehicle so that the rate of change of the vehicle's speed is relatively gradual, and also controls the vehicle so that the distance between vehicles is relatively large. Thus, there is little need for the driver to manually correct the rate of change of speed and the distance between vehicles. In addition, an increase in occupant anxiety regarding the vehicle's behavior is suppressed. Thus, a decrease in the comfort of the vehicle's occupants is suppressed.

[0008] In a driving support device according to one aspect of the present invention, The processor assigns the second speed change rate to the target value of the speed change rate and the second inter-vehicle distance to the target value of the inter-vehicle distance in the specific scene.

[0009] According to this system, if the system mistakenly determines that the vehicle and trailer are not connected while the vehicle is in motion, the same automatic speed adjustment process as before the misdetermination occurred will continue. This helps maintain a high level of passenger comfort.

[0010] In another aspect of the present invention, a driving support device, The aforementioned electrical signal line is a wire, one end of which can be connected to a first connector provided in the first electronic circuit, and the other end of which can be connected to a second connector provided in the second electronic circuit. With one end of the electric wire connected to the first connector and the other end of the electric wire connected to the second connector, the voltage of the electrical signal reaches a predetermined first level. The system is configured such that the voltage of the electrical signal becomes a predetermined second voltage if one end of the electric wire becomes detached from the first connector, if the other end of the electric wire becomes detached from the second connector, or if the electric wire is broken.

[0011] According to this, the configuration (electronic circuit) for detecting the coupling status between the vehicle and the trailer. Because it is relatively simple, component costs can be reduced. [Brief explanation of the drawing]

[0012] [Figure 1] Figure 1 is a block diagram of a driver assistance device according to one embodiment of the present invention. [Figure 2] Figure 2 is a circuit diagram of an electronic circuit installed to send and receive electrical signals between the vehicle and the trailer. [Figure 3] Figure 3 is a flowchart of the program executed by the CPU to realize a predetermined function of the driver assistance system.

[0013] (Summary) A driver assistance device 1 according to one embodiment of the present invention is applied to a vehicle V0 equipped with an autonomous driving function (hereinafter referred to as "the vehicle"). The driver assistance device 1 includes an automatic speed adjustment function that assists the driver's operation by automatically adjusting the speed of the vehicle when the autonomous driving function of the vehicle is disabled. The driver assistance device 1 may be configured so that this automatic speed adjustment function operates as part of the autonomous driving function.

[0014] As shown in Figure 1, the vehicle is capable of towing trailer T. The vehicle can also travel without trailer T attached (as a standalone vehicle).

[0015] (Specific configuration) Next, the configuration of the driver assistance system 1 will be described in detail. As shown in Figure 1, the driver assistance system 1 includes an ECU 10, an on-board sensor 20, a drive unit 30, and a braking unit 40.

[0016] The ECU10 includes a microcomputer equipped with a CPU10a, ROM10b, RAM10c, timer10d, etc., and this microcomputer and other electronic components are mounted on a printed circuit board PWBa (see Figure 2).

[0017] The in-vehicle sensor 20 includes a millimeter-wave radar 21, a sonar 22, a camera 23, and a speed sensor 24.

[0018] The millimeter-wave radar 21 includes a transmitting / receiving unit and a signal processing unit (not shown). The transmitting / receiving unit emits millimeter-wave radio waves (hereinafter referred to as "millimeter waves") around the vehicle and receives millimeter waves (reflected waves) reflected by three-dimensional objects located within the radiation range. The signal processing unit calculates the distance between the vehicle and the three-dimensional object, the direction of the three-dimensional object relative to the vehicle, and the velocity of the three-dimensional object relative to the vehicle, based on the time from when the transmitting / receiving unit emits the millimeter waves until the reflected waves are received, the phase difference between the transmitted millimeter waves and the received reflected waves, and the attenuation level of the reflected waves, and provides the calculation results (target information) to the ECU 10.

[0019] The sonar 22 intermittently emits ultrasonic waves into the area surrounding the vehicle and receives ultrasonic waves (reflected waves) reflected by three-dimensional objects. Based on the time from the emission of ultrasonic waves to the reception of reflected waves, the sonar 22 calculates the distance between the vehicle and the three-dimensional object, the direction of the three-dimensional object relative to the vehicle, etc., and provides the calculation results (object information) to the ECU 10.

[0020] Camera 23 includes a plurality of imaging devices. Each imaging device incorporates an imaging element such as a CCD (charge coupled device) or a CIS (CMOS image sensor), for example. Each imaging device is installed, for example, on the front part, the right side part, the left side part, and the rear part of the host vehicle. Each imaging device captures the surrounding area of the host vehicle at a predetermined frame rate to acquire image data. Camera 23 further includes an image analysis device. The image analysis device sequentially acquires image data from each imaging device. The image analysis device analyzes the acquired image data to obtain information regarding a target located around the host vehicle from the image. For example, the image analysis device identifies (recognizes) the type of the target located around the host vehicle (e.g., other vehicles and other targets), and provides the identification result (target information) to ECU 10.

[0021] The speed sensor 24 detects the rotational speed (wheel speed) of each wheel, and calculates the speed sp0 (measured value) of the host vehicle based on each wheel speed. The speed sensor 24 provides the calculation result to ECU 10.

[0022] The drive device 30 applies a driving force to the drive wheels. The drive device 30 includes an engine ECU, an internal combustion engine, a transmission, a driving force transmission mechanism that transmits the driving force to the wheels, and the like. The engine ECU acquires information (target value) representing a target driving force from another ECU (ECU 10). The engine ECU drives the throttle valve of the internal combustion engine to make the driving force applied to the drive wheels match the target value.

[0023] When the vehicle to which the driving support device 1 is applied is a hybrid vehicle (HEV), the engine ECU can adjust the output (driving force) of either one or both of the "internal combustion engine and the electric motor" as the vehicle drive source. When the vehicle to which the driving support device 1 is applied is a battery electric vehicle (BEV), instead of the engine ECU, a motor ECU that adjusts the output (driving force) of the "electric motor" as the vehicle drive source is used.

[0024] The braking system 40 applies braking force to the wheels (brake discs). The braking system 40 includes a brake ECU 41, a brake caliper 42, and the like. The brake caliper includes an actuator that presses the brake pads against the brake disc. The brake ECU 41 obtains information (target value) representing the target braking force from another ECU (ECU 10). The brake ECU 41 controls the brake caliper 42 to match the braking force applied to the vehicle's wheels (brake discs) to the target value.

[0025] As mentioned above, the vehicle is capable of towing trailer T. As shown in Figure 2, trailer T is equipped with a braking device 50 that applies braking force to its wheels. The braking device 40, like the braking device 40, includes a brake ECU 51, brake calipers 52, etc. The electronic components constituting the brake ECU 51 are mounted on a printed circuit board PWBb. When trailer T is coupled to the vehicle, ECU 10 is connected to brake ECU 51 via cable C. Brake ECU 51 obtains a target value for braking force from ECU 10 via cable C and controls brake calipers 52 so that the braking force applied to the wheels of trailer T matches the target value.

[0026] Here, as shown in Figure 2, the vehicle and trailer T include electronic circuits Ea and Eb for detecting the coupling state (coupled / uncoupled) of the two. Electronic circuit Ea is mounted on a printed circuit board PWBa. Electronic circuit Ea is connected to the input port IN of the CPU 10a. Electronic circuit Ea includes an electrical resistor R and a socket Sa. One end of the electrical resistor R is connected to the input port IN, and the other end is connected to the positive terminal line (e.g., +5V) of the power supply of the ECU 10. In other words, the electrical resistor R is a pull-up resistor. The socket Sa also includes multiple terminals San (n=1,2,3...). One end of the electrical resistor R and the input port IN are connected to terminal Sa1. The negative terminal line (0V (reference potential)) of the power supply of the ECU 10 is connected to terminal Sa2. Furthermore, the signal lines used to transmit the target braking force value to the trailer T (such as the CAN port (differential signal port) of CPU 10a, the positive line, and the negative line) are connected to terminals Sa3 to Sa6. Note that the input impedance of input port IN is very large compared to the resistance value of the electrical resistor R.

[0027] The electronic circuit Eb is mounted on the printed circuit board PWBb of the brake system 50 of the trailer T. The electronic circuit Eb includes socket Sb, which is the same as socket Sa. Terminals Sb1 and Sb2 of socket Sb are connected to the negative terminal line of the power supply of the brake ECU 51. Terminals Sb3 to Sb6 are connected to the CAN port, positive terminal line, and negative terminal line of the power supply of the brake ECU 51, respectively.

[0028] Cable C contains multiple wires Wn (n=1,2,...) corresponding to terminals San and Sbn of sockets Sa and Sb, respectively. Plugs Pa and Pb are provided at both ends of cable C. Plugs Pa and Pb contain terminals Pan and Pbn corresponding to terminals San and Sbn. Both ends of each wire Wn are connected to terminals Pan and Pbn of plugs Pa and Pb, respectively. When the vehicle and trailer T are coupled, plugs Pa and Pb are fitted into sockets Sa and Sb. As a result, terminals Pan and San make contact (conductivity), and terminals Pbn and Sbn make contact (conductivity). In this state, the target value of the braking force can be transmitted from ECU 10 to brake ECU 51. Also in this state, current flows from the positive line connected to the other end of the electrical resistor R through the electrical resistor R and cable C to the negative line of the printed circuit board PWBb. In other words, the voltage applied to input port IN (voltage of the electrical signal) is "0V". Therefore, the logic level of input port IN of CPU 10a is "L". On the other hand, when the connection between the vehicle and trailer T is released, plugs Pa and Pb are removed from sockets Sa and Sb. In this state, current flows from the positive line connected to the other end of the electrical resistor R through the electrical resistor R to input port IN. In other words, the voltage applied to input port IN (voltage of the electrical signal) is "+5V". Therefore, the logic level of input port IN is "H". CPU 10a is configured to determine that trailer T is connected to the vehicle when the logic level of input port IN is "L", and to determine that trailer T is not connected to the vehicle when the logic level of input port IN is "H".

[0029] (Operation) When the ignition switch is ON, the ECU 10 sequentially determines the presence or absence of a preceding vehicle V1 and, based on the determination result, executes an automatic speed adjustment process to control the drive system, etc. (drive system 30 and / or brake system 40). This function (automatic speed adjustment function) is also called adaptive cruise control (ACC). This function includes a constant speed driving function and a distance keeping function. In the automatic speed adjustment process, the ECU 10 assigns a predetermined value to the target value of the vehicle's acceleration α0 when accelerating the vehicle (target acceleration αat). On the other hand, in the automatic speed adjustment process, the ECU 10 assigns a predetermined value to the target value of the vehicle's acceleration α0 when decelerating the vehicle (target value of backward acceleration (target deceleration αdt)). In this embodiment, the magnitude (absolute value) of the target acceleration αat and the magnitude (absolute value) of the target deceleration αdt are the same. However, their magnitudes may be different.

[0030] (Constant speed driving function) The ECU 10 determines the presence or absence of a preceding vehicle V1 based on information acquired from forward sensors (millimeter-wave radar 21, sonar 22, and camera 23). If no preceding vehicle V1 exists, the ECU 10 executes a constant-speed driving process. Specifically, the ECU 10 assigns an upper limit spmax set by the driver to the target value of the vehicle's speed sp0 (target speed spt). The ECU 10 then controls the drive system, etc., so that the speed sp0 matches the target speed spt. For example, if the vehicle's speed sp0 is lower than the target speed spt, the ECU 10 controls the drive system, etc., so that the vehicle's acceleration α0 matches the target acceleration αat. Hereinafter, this process will be referred to as the "automatic acceleration process". On the other hand, for example, if the vehicle's speed sp0 is higher than the target speed spt, the ECU 10 controls the drive system, etc., so that the vehicle's acceleration α0 (deceleration) matches the target deceleration αdt. Hereinafter, this process will be referred to as the "automatic deceleration process". This causes the vehicle's speed sp0 to approach the target speed spt (=spmax). Furthermore, even if a preceding vehicle V1 exists, if its speed sp1 is greater than the upper limit spmax, the ECU 10 will execute constant speed driving control.

[0031] (Distance keeping control) On the other hand, if the ECU 10 determines that a preceding vehicle V1 exists and the speed sp1 of the preceding vehicle V1 is less than the upper limit spmax, it executes the following distance maintenance process. Specifically, the ECU 10 obtains the following distance D between the preceding vehicle V1 and its own vehicle based on the information obtained from the on-board sensor 20. The ECU 10 also assigns a predetermined value to the target value (target following distance Dt) of the following distance D. The ECU 10 controls the drive system and the like so that the following distance D matches the target value (target following distance Dt).

[0032] When the speed sp1 of the preceding vehicle V1 relative to the speed sp0 of the own vehicle (relative speed spr = sp1 - sp0) is greater than "0", the distance between vehicles D increases. When the distance between vehicles D is greater than the target distance between vehicles Dt, the ECU 10 accelerates the own vehicle so that the speed sp0 of the own vehicle is greater than the speed sp1 of the preceding vehicle V1. That is, the ECU 10 assigns a predetermined value to the target acceleration αat. The ECU 10 then controls the drive system etc. so that the acceleration α0 of the own vehicle matches the target acceleration αat (automatic acceleration processing). As a result, the distance between vehicles D decreases and approaches the target distance between vehicles Dt. From the point when the distance between vehicles D matches the target distance between vehicles Dt, the ECU 10 controls the drive system etc. so that the own vehicle travels at the same speed as the preceding vehicle V1.

[0033] On the other hand, when the relative velocity spr is less than "0", the distance between vehicles D decreases. When the distance between vehicles D is less than the target distance between vehicles Dt, the ECU 10 decelerates its own vehicle. That is, the ECU 10 assigns a predetermined value to the target deceleration αdt. The ECU 10 then controls the drive system and other components so that the acceleration α0 (measured value) of its own vehicle matches the target deceleration αdt (automatic deceleration process). As a result, the distance between vehicles D increases and approaches the target distance between vehicles Dt. From the point when the distance between vehicles D matches the target distance between vehicles Dt, the ECU 10 controls the drive system and other components so that its own vehicle travels at the same speed as the preceding vehicle V1.

[0034] The target following distance Dt is related to the speed sp0 of the vehicle itself and the speed sp1 of the preceding vehicle V1. For example, the target following distance Dta when speeds sp0 and sp1 are relatively small is smaller than the target following distance Dtb when speeds sp0 and sp1 are relatively large. A database (table) representing the relationship between speeds sp0, sp1 and the target following distance Dt, or a calculation formula for determining the target following distance Dt, is stored in the ROM 10b. The ECU 10 determines the target following distance Dt based on the above database or calculation formula.

[0035] Incidentally, when a trailer T is attached to the vehicle, the overall weight of the vehicle is relatively large. Generally, the inertial force acting on the vehicle (the vehicle and trailer T) is larger when the vehicle weight is large (when a trailer T is attached to the vehicle) compared to when the vehicle weight is small (when a trailer T is not attached to the vehicle). Therefore, when the vehicle is accelerated by the automatic speed adjustment process while the vehicle and trailer T are attached, and the acceleration of the vehicle is relatively large, there is a risk of overshoot, where the speed sp0 temporarily exceeds the target speed spt after reaching the target speed spt. Conversely, when the vehicle is decelerated by the automatic speed adjustment process, and the deceleration (absolute value) of the vehicle is relatively large, there is a risk of undershoot, where the speed sp0 temporarily falls below the target speed spt after reaching the target speed spt. Such overshoot or undershoot of speed sp0 relative to the target speed spt (repeated acceleration and deceleration within a short period) can impair the comfort of the occupants.

[0036] Furthermore, if the vehicle is accelerated by the automatic speed adjustment process while the vehicle is coupled with trailer T, and the acceleration of the vehicle is relatively large, there is a risk of undershoot, where the distance D between vehicles decreases and temporarily falls below the target distance Dt after reaching it. In this case, the vehicle may approach the preceding vehicle V1 excessively closely, potentially increasing the occupants' anxiety and compromising their comfort.

[0037] Also, when the vehicle weight is relatively large, a larger driving force is required to accelerate the vehicle, so the engine speed may become relatively high. In this case, the engine noise is large, and the comfort of the passengers is impaired.

[0038] Therefore, the ECU 10 determines whether a trailer T is connected to the host vehicle (whether the vehicle weight is large), and determines values to be assigned to the target acceleration αat, the target deceleration αdt, and the target inter-vehicle distance Dt according to the determination result. Specifically, the ECU 10 (CPU 10a) monitors the logic level of the input port IN. When the logic level of the input port IN is "H" (when the trailer T is not connected to the host vehicle (first state)), a predetermined value αa1 (>αa2) with a relatively large absolute value is assigned to the target acceleration αat, and a predetermined value αd1 (=−αa1) with a relatively large absolute value is assigned to the target deceleration αdt. Also, in this case, the ECU 10 assigns a relatively small predetermined value D1 (<D2) to the target inter-vehicle distance Dt. On the other hand, when the logic level of the input port IN is "L" (when the trailer T is connected (second state)), the ECU 10 assigns a predetermined value αa2 (<αa1) with a relatively small absolute value to the target acceleration αat, and a predetermined value αd2 (=−αa2) with a relatively small absolute value to the target deceleration αdt. Also, in this case, the ECU 10 assigns a relatively large predetermined value D2 (>D 1) to the target inter-vehicle distance Dt.

[0039] Here, due to vibrations during the movement of the vehicle and trailer T, one or both of the plugs Pa and Pb may detach from the sockets Sa and Sb. Also, due to the same vibrations, the wire W1 may break. In this case, the logic level of input port IN will transition from "L" to "H". Therefore, ECU 10 will determine that trailer T is not connected to the vehicle, even though it is. In this scenario, if ECU 10 were to assign predetermined values ​​αa1 and αd1 to the target acceleration αat and target deceleration αdt, respectively, and assign a predetermined value D1 to the target inter-vehicle distance Dt, then an overshoot or undershoot of the speed sp0 (measured value) relative to the target speed spt would occur. Also, in this case, there is a risk of an overshoot or undershoot of the inter-vehicle distance D (measured value) relative to the target inter-vehicle distance Dt. Furthermore, there is a risk that the engine speed of the vehicle will become relatively high. Furthermore, there is a risk that the driver may need to manually adjust the acceleration α0 and the distance D between vehicles.

[0040] Therefore, the ECU 10 acquires the logic level of input port IN immediately after the ignition switch of its own vehicle transitions from the off state to the on state, and before the own vehicle starts moving. If the logic level is "L", and then transitions to "H" after the own vehicle and trailer T start moving, it is highly likely that plugs Oa and Pb have fallen out of sockets Sa and Sb, or that wire W1 has been broken. In this case, the ECU 10 assigns a predetermined value αa3 (<αa1) with a relatively small absolute value to the target acceleration αat and target deceleration αdt, and assigns a predetermined value αd3 (=-αa3) with a relatively small absolute value to the target deceleration αdt. In other words, the ECU 10 controls its own vehicle so that the rate of change of vehicle speed is relatively gradual. Also in this case, the ECU 10 assigns a predetermined value D3 (>D1) with a relatively large absolute value to the target inter-vehicle distance Dt. Here, it is desirable that the absolute values ​​of predetermined values ​​αa3 and αd3 are equal to the absolute values ​​of predetermined values ​​αa2 and αd2. Also, it is desirable that predetermined value D3 is equal to predetermined value D2. The ECU 10 determines that the vehicle has not yet started moving if the vehicle's shift position is "P (parking position)" immediately after the ignition switch transitions to the ON state. Subsequently, it determines that the vehicle has started moving when the shift position transitions to "D (forward position)" or "R (reverse position)".

[0041] Next, referring to Figure 3, we will describe the program PR1 executed by the CPU 10a of the ECU 10 (hereinafter simply referred to as "CPU") to realize the function of the driver assistance device 1, which determines the values ​​to be assigned to the target acceleration αat, target deceleration αdt, and target inter-vehicle distance Dt according to the determination result of the coupling state between the vehicle and the trailer T. The CPU starts executing program PR1 when the ignition switch of the vehicle transitions from the off state to the on state.

[0042] (Program PR1) The CPU starts executing program PR1 from step 100 and proceeds to step 101.

[0043] In step 101, the CPU determines whether the ignition switch has been turned ON but the vehicle has not yet started moving (i.e., whether the shift position is "P"). If the CPU determines that the vehicle has not yet started moving (101: Yes), it proceeds to step 102. On the other hand, if the CPU does not determine that the vehicle has not yet started moving (101: No), it proceeds to step 105, which will be described later.

[0044] In step 102, the CPU determines whether the logical level of input port IN is "H". If the CPU determines that the logical level of input port IN is "H" (102: Yes), it proceeds to step 103. On the other hand, if the CPU does not determine that the logical level of input port IN is "H" (102: No), it proceeds to step 104.

[0045] In step 103, the CPU assigns predetermined values ​​αa1 and αd1 to the target acceleration αat and target deceleration αdt, respectively, and assigns a predetermined value D1 to the target inter-vehicle distance Dt. The CPU then returns to step 101.

[0046] In step 104, the CPU assigns predetermined values ​​αa2 and αd2 to the target acceleration αat and target deceleration αdt, respectively, and assigns a predetermined value D2 to the target inter-vehicle distance Dt. The CPU then returns to step 101.

[0047] In step 105, the CPU determines whether the logical level of input port IN has transitioned from "L" to "H". If the CPU determines that the logical level of input port IN has transitioned from "L" to "H" (105: Yes), it proceeds to step 106. On the other hand, if the CPU does not determine that the logical level of input port IN has transitioned from "L" to "H" (105: No), it returns to step 101.

[0048] In step 106, the CPU assigns predetermined values ​​αa3 and αd3 to the target acceleration αat and target deceleration αdt, respectively, and assigns a predetermined value D3 to the target inter-vehicle distance Dt. The CPU then returns to step 101.

[0049] (effect) It is rare for a trailer T to be intentionally detached from a vehicle while it is traveling with the trailer T attached. Therefore, when the ECU 10 of the driver assistance device 1 according to this embodiment detects a transition from the second state (attached state) to the first state (unattached state) while traveling, it controls the vehicle (drive unit 30) so that the acceleration α0 of the vehicle becomes relatively gentle (equivalent to the second state), and also controls the vehicle (drive unit 30 and / or braking unit 40) so that the distance between vehicles D becomes relatively large (equivalent to the second state). As a result, there is little need for the driver to manually adjust the speed and distance between vehicles. In addition, an increase in occupant anxiety regarding the vehicle's behavior is suppressed. As a result, a decrease in the comfort of the vehicle's occupants is suppressed.

[0050] (modified version) The configuration for determining the connection status between the vehicle and trailer T is not limited to the above configuration. For example, the ECU 10 may determine that the vehicle and trailer T are not connected if the duration of the interrupted communication with the brake ECU 51 via the CAN port exceeds a threshold. [Explanation of Symbols]

[0051] 1...Vehicle control unit, 10...ECU, 20...On-board sensor, 30...Drive system, 40...Brake system, T...Trailer, V0...Vehicle (own vehicle)

Claims

1. An automatic speed adjustment process that controls the drive and / or braking systems of a vehicle so that the speed of the vehicle capable of towing a trailer is automatically adjusted, the process includes controlling the drive and / or braking systems so that the rate of change of speed when accelerating or decelerating the vehicle matches a predetermined target value, and, when there is a preceding vehicle in front of the vehicle, controlling the drive and / or braking systems so that the distance between the vehicle and the preceding vehicle matches a predetermined target value, and further, a predetermined electronic circuit comprising a first electronic circuit provided in the vehicle and a second electronic circuit provided in the trailer, and the first electronic circuit and the second electronic circuit The system includes a processor that can detect the coupling state between the vehicle and the trailer based on electrical signals input from an electronic circuit including connected electrical signal lines, and is configured to assign a predetermined first rate of change to the target value of the rate of change of speed and a predetermined first distance to the target value of the distance between vehicles in a first state where the vehicle and the trailer are not coupled, and to assign a predetermined second rate of change that is slower than the first rate of change to the target value of the rate of change of speed and a predetermined second distance that is greater than the first distance between vehicles to the target value of the distance between vehicles in a second state where the vehicle and the trailer are coupled. The aforementioned processor is configured to, in a specific scene where it detects that the vehicle has transitioned from the second state to the first state based on the electrical signal while it is in motion, assign a value less gradual than the first rate of change to the target value of the rate of change of speed, and assign a value greater than the first distance between vehicles to the target value of the distance between vehicles.

2. In the driving support device according to claim 1, The processor is configured to assign the second speed change rate to the target value of the speed change rate and the second inter-vehicle distance to the target value of the inter-vehicle distance in the specific scene.

3. In the driving support device according to claim 1 or claim 2, The aforementioned electrical signal line is a wire, one end of which can be connected to a first connector provided in the first electronic circuit, and the other end of which can be connected to a second connector provided in the second electronic circuit. With one end of the electric wire connected to the first connector and the other end of the electric wire connected to the second connector, the voltage of the electrical signal reaches a predetermined first level. A driving support device configured such that the voltage of the electrical signal becomes a predetermined second voltage when one end of the electric wire becomes detached from the first connector, when the other end of the electric wire becomes detached from the second connector, or when the electric wire is broken.

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