Driving assistance device

Abstract

The present application provides a kind of driving assistance device, in the vehicle that can tow trailer, in the case where misjudgment is not linked, passenger's comfort can be inhibited to reduce.The driving assistance device in the state that the vehicle is not linked with trailer, i.e. first state, the target value of the speed change rate when making the vehicle accelerate or decelerate is assigned to the first speed change rate specified, and the target value of the inter-vehicle distance is assigned to the first inter-vehicle distance specified, in the state that the vehicle is linked with trailer, i.e. second state, the target value of the speed change rate is assigned to the second speed change rate specified slower than the first speed change rate, and the target value of the inter-vehicle distance is assigned to the second inter-vehicle distance greater than the first inter-vehicle distance.

Description

Technical Field

[0001] This invention relates to a driving assistance device that assists in adjusting the speed of a vehicle capable of towing a trailer. Background Technology

[0002] A driving assistance device is proposed that assists in adjusting the speed of a vehicle capable of towing a trailer (see, for example, Patent Document 1 below). The processor of this driving assistance device (hereinafter referred to as the "conventional device") performs a constant-speed driving process, which controls the vehicle's drive and / or braking devices to ensure that the vehicle's speed (measured value) matches a speed preset by the driver. When a preceding vehicle is present, a distance-keeping process is performed, which controls the vehicle's drive and / or braking devices to ensure that the distance between the preceding vehicle and the vehicle matches a predetermined target distance. In both the constant-speed driving process and the distance-keeping process, when a temporary acceleration of the vehicle is required, the processor determines a target value for the vehicle's acceleration (target acceleration) and controls the drive to ensure that the vehicle's acceleration (measured value) matches the target acceleration. Here, the processor determines whether a trailer is attached to the vehicle and determines the target acceleration and target distance based on the result. That is, when the processor determines that the trailer is not connected to the vehicle, it allocates the optimal values ​​for the target acceleration and the target inter-vehicle distance when the vehicle weight is relatively small. On the other hand, when the processor determines that the trailer is connected to the vehicle, it allocates the optimal values ​​for the vehicle acceleration when the vehicle weight is relatively large to the target acceleration.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2021-133890 Summary of the Invention

[0004] The processor of the existing device is connected to the electronic circuitry on the trailer side via an electrical signal line located between the vehicle and the trailer, and detects the connection status between the vehicle and the trailer based on the electrical signal input from this signal line. However, during the operation of the vehicle and trailer using this existing device, malfunctions may occur in the aforementioned electrical communication line. For example, vibrations generated by the vehicle and trailer during operation may cause the electrical communication line to break. Furthermore, the connection between the electrical communication line and the processor (connector) and / or the connection between the electrical communication line and the electronic circuitry on the trailer side (connector) may change from a conductive state to a non-conductive state (the connector plug may detach from the socket). In these cases, even if the vehicle and trailer are connected, the processor may incorrectly determine (mistakenly determine) that the vehicle and trailer are not connected, and thus allocate the optimal values ​​for the target acceleration and target inter-vehicle distance, respectively, based on the vehicle weight. Therefore, the acceleration of the vehicle (vehicle and trailer) is not optimized during constant speed driving and inter-vehicle distance maintenance. Furthermore, the inter-vehicle distance is not optimized during inter-vehicle distance maintenance. If the vehicle's acceleration and inter-vehicle distance become inappropriate due to the aforementioned misjudgments, the driver may need to manually correct these parameters. Furthermore, occupants' anxiety regarding the automatic speed adjustment function of the driver assistance system may increase. Thus, if acceleration (deceleration) and inter-vehicle distance are not optimized due to the aforementioned misjudgments related to the connection status between the vehicle and the trailer, occupant comfort may be compromised.

[0005] One of the objectives of this invention is to provide a driving assistance device that, in a vehicle capable of towing a trailer, can suppress a decrease in occupant comfort when the vehicle is mistakenly determined to be disconnected from the trailer.

[0006] To achieve the above objectives, the driving assistance device 1 of the present invention includes a processor.

[0007] The processor is configured to perform automatic speed adjustment processing, which controls the drive unit 30 and / or braking unit 40 of the vehicle to automatically adjust the speed sp0 of the vehicle V0 capable of towing the trailer T. The automatic speed adjustment processing includes: controlling the drive unit and / or the braking unit to ensure that the rate of change of speed α0 of the vehicle during acceleration and deceleration is consistent with predetermined target values ​​αat and αdt; and, when a preceding vehicle V1 is in front of the vehicle, controlling the drive unit and / or the braking unit to ensure that the distance between the vehicle and the preceding vehicle is consistent with a predetermined target value Dt. Furthermore, the processor can detect the connection status between the vehicle and the trailer based on an electrical signal input from an electronic circuit. The circuit is a defined electronic circuit, comprising: a first electronic circuit Ea, disposed in the vehicle; a second electronic circuit Eb, disposed in the trailer; and an electrical signal line C, connecting the first electronic circuit and the second electronic circuit. In the first state, where the vehicle and the trailer are not connected, a defined first speed change rate αa1 and αd1 are assigned to the target value of the speed change rate, and a defined first inter-vehicle distance D1 is assigned to the target value of the inter-vehicle distance. In the second state, where the vehicle and the trailer are connected, a defined second speed change rate αa2 and αd2, which are slower than the first speed change rate, are assigned to the target value of the speed change rate, and a second inter-vehicle distance D2, which is larger than the first inter-vehicle distance, is assigned to the target value of the inter-vehicle distance.

[0008] The processor is configured as follows: during the vehicle's operation, in a specific scenario where the vehicle transitions from the second state to the first state based on the electrical signal, a value slower than the first rate of change of speed is assigned to the target value of the rate of change of speed, and a value larger than the first inter-vehicle distance is assigned to the target value of the inter-vehicle distance.

[0009] While the vehicle is traveling with a trailer attached, the trailer is rarely intentionally detached from the vehicle. Therefore, when the processor of the driving assistance device according to this invention detects a transition from a second state (attached state) to a first state (disattached state) during travel, it controls the vehicle to make the rate of change of speed relatively slow and to make the inter-vehicle distance relatively increase. Therefore, the need for the driver to manually correct the rate of change of speed and inter-vehicle distance is low. Furthermore, it suppresses the increase in passenger anxiety regarding vehicle behavior. Therefore, it suppresses the reduction in passenger comfort.

[0010] In a driving assistance device according to one aspect of the present invention,

[0011] In the specific scenario, the processor assigns the second rate of change of speed to a target value of the rate of change of speed, and assigns the second workshop distance to a target value of the workshop distance.

[0012] Therefore, when the vehicle is connected to the trailer, if it is mistakenly determined that the vehicle and trailer are not connected, the automatic speed adjustment process continues as before the mistaken determination occurred. As a result, the comfort of the occupants is maintained at a high level.

[0013] In another aspect of the present invention, the driving assistance device is configured as follows:

[0014] The 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.

[0015] With one end of the wire connected to the first connector and the other end connected to the second connector, the voltage of the electrical signal reaches a predetermined first level.

[0016] In the event that one end of the wire is detached from the first connector, the other end of the wire is detached from the second connector, or the wire is broken, the voltage of the electrical signal becomes a predetermined second voltage.

[0017] Therefore, the structure (electronic circuit) used to detect the connection status between the vehicle and the trailer is relatively simple, thus reducing the cost of parts. Attached Figure Description

[0018] Figure 1 This is a block diagram of a driving assistance device according to one embodiment of the present invention.

[0019] Figure 2 It is a circuit diagram of an electronic circuit used for receiving and transmitting signals between the vehicle and the trailer.

[0020] Figure 3 It is a flowchart of the program executed by the CPU to implement the specified functions of the driving assistance device. Detailed Implementation

[0021] (roughly)

[0022] One embodiment of the present invention relates to a driving assistance device 1, which is applied, for example, to a vehicle V0 (hereinafter referred to as "the vehicle") equipped with an autonomous driving function. The driving assistance device 1 includes an automatic speed adjustment function that assists the driver's driving operation by automatically adjusting the vehicle's speed when the vehicle's autonomous driving function is disabled. Alternatively, the driving assistance device 1 may be configured such that the automatic speed adjustment function operates as part of the autonomous driving function.

[0023] like Figure 1 As shown, this vehicle is capable of towing trailer T. Additionally, this vehicle can travel independently without being attached to trailer T (as a standalone vehicle).

[0024] (Specific structure)

[0025] Next, the structure of the driving assistance device 1 will be described in detail. For example... Figure 1 As shown, the driving assistance device 1 includes an ECU 10, an on-board sensor 20, a drive unit 30, and a braking device 40.

[0026] ECU10 includes a microcomputer with CPU10a, ROM10b, RAM10c, timer10d, etc., which, along with other electronic components, is mounted on a printed circuit board PWBa (reference). Figure 1 ).

[0027] The vehicle-mounted sensors 20 include millimeter-wave radar 21, sonar 22, camera 23 and speed sensor 24.

[0028] The millimeter-wave radar 21 includes a transceiver unit and a signal processing unit (not shown). The transceiver unit radiates millimeter-wave radio waves (hereinafter referred to as "millimeter waves") into the vicinity of 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 speed of the three-dimensional object relative to the vehicle, based on the time from the time the transceiver unit radiates the millimeter waves to the time it receives the reflected waves, the phase difference between the transmitted millimeter waves and the received reflected waves, and the attenuation degree of the reflected waves, and provides the calculation results (target information) to the ECU 10.

[0029] Sonar 22 intermittently radiates ultrasonic waves into the area surrounding the vehicle and receives ultrasonic waves reflected by three-dimensional objects (reflected waves). Based on the time from radiating ultrasonic waves to receiving reflected waves, 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 (target information) to ECU 10.

[0030] Camera 23 includes multiple imaging devices. Each imaging device incorporates an imaging element such as a charge-coupled device (CCD) or a CMOS image sensor (CIS). Each imaging device is positioned, for example, on the front, right, left, and rear surfaces of the vehicle. Each imaging device captures image data of the vehicle's surrounding area at a predetermined frame rate. Camera 23 also 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 and extracts information related to targets located around the vehicle. For example, the image analysis device identifies the types of targets located around the vehicle (e.g., other vehicles and other targets) and provides this identification result (target information) to ECU 10.

[0031] Speed ​​sensor 24 detects the rotational speed (wheel speed) of each wheel and calculates the vehicle's speed sp0 (measured value) based on the wheel speed. Speed ​​sensor 24 then provides the calculation result to ECU 10.

[0032] The drive unit 30 applies driving force to the drive wheels. The drive unit 30 includes an engine ECU, an internal combustion engine, a transmission, and a drive force transmission mechanism that transmits driving force to the wheels. The engine ECU obtains information (target value) representing the target driving force from other ECUs (ECU 10). The engine ECU drives the throttle valve of the internal combustion engine to ensure that the driving force applied to the drive wheels matches the target value.

[0033] Furthermore, when the vehicle using driver assistance device 1 is a hybrid electric vehicle (HEV), the engine ECU can adjust the output (driving force) of any one or both of the "internal combustion engine and electric motor" that serve as the vehicle's drive source. And, when the vehicle using driver assistance device 1 is a battery electric vehicle (BEV), instead of the engine ECU, an electric motor ECU is used to adjust the output (driving force) of the "electric motor" that serves as the vehicle's drive source.

[0034] The braking device 40 applies braking force to the wheels (brake discs). The braking device 40 includes a brake ECU 41, brake calipers 42, etc. The brake calipers include actuators that press the brake pads onto the brake discs. The brake ECU 41 obtains information (target value) indicating the target braking force from other ECUs (ECU 10). The brake ECU 41 controls the brake calipers 42 to ensure that the braking force applied to the wheels (brake discs) of the vehicle matches the target value.

[0035] As stated above, this vehicle is capable of towing trailer T. Figure 2As shown, the trailer T is equipped with a braking device 50 that applies braking force to its wheels. Similar to the braking device 40, the braking device 50 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 the trailer T is connected to the vehicle, the ECU 10 is connected to the brake ECU 51 via cable C. The brake ECU 51 obtains the target value of the braking force from the ECU 10 via cable C and controls the brake calipers 52 to ensure that the braking force applied to the wheels of the trailer T matches the target value.

[0036] Here, as Figure 2 As shown, the vehicle and trailer T include electronic circuits Ea and Eb for detecting their connection status (connected / disconnected). Electronic circuit Ea is mounted on the printed circuit board PWBa. Electronic circuit Ea is connected to the input port IN of CPU10a. Electronic circuit Ea includes a resistor R and a socket Sa. One end of resistor R is connected to the input port IN, and the other end is connected to the positive line (e.g., +5V) of the power supply of ECU10. That is, resistor R is a pull-up resistor. Socket Sa includes multiple terminals San (n=1,2,3...). One end of resistor R and the input port IN are connected to terminal Sa1. The negative line (0V (reference potential)) of the power supply of ECU10 is connected to terminal Sa2. In addition, signal lines (the CAN port (differential signal port) of CPU10a, the positive line, the negative line, etc.) for sending the target value of braking force to trailer T are connected to terminals Sa3 to Sa6. In addition, the input impedance of the input port IN is very large compared to the resistance value of the resistor R.

[0037] Electronic circuit Eb is mounted on the printed circuit board PWBb of the braking device 50 of trailer T. 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 power line of the braking ECU 51. In addition, terminals Sb3 to Sb6 are connected to the CAN port, the positive power line, and the negative power line of the braking ECU 51, respectively.

[0038] Cable C includes 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 include terminals Pan and Pbn corresponding to terminals San and Sbn, respectively. The two ends of each wire Wn are connected to terminals Pan and Pbn of plugs Pa and Pb, respectively. When the vehicle is connected to the trailer T, plugs Pa and Pb are engaged in sockets Sa and Sb. Thus, terminal Pan contacts (conducts) terminal San, and terminal Pbn contacts (conducts) terminal Sbn. In this state, the target value of braking force can be sent from ECU10 to braking ECU51. Furthermore, in this state, current flows from the positive line connected to the other end of resistor R through resistor R and cable C to the negative line of printed circuit board PWBb. That is, the voltage (electrical signal voltage) applied to input port IN is "0V". Therefore, the logic level of input port IN of CPU10a is "L". On the other hand, when disconnecting the vehicle from the trailer T, plugs Pa and Pb are pulled out of sockets Sa and Sb. In this state, current flows from the positive line connected to the other end of resistor R through resistor R to input port IN. That is, the voltage applied to input port IN (the voltage of the electrical signal) is "+5V". Therefore, the logic level of input port IN is "H". CPU 10a is configured to determine that the trailer T is connected to the vehicle when the logic level of input port IN is "L", and to determine that the trailer T is not connected to the vehicle when the logic level of input port IN is "H".

[0039] (Work)

[0040] With the ignition switch on, the ECU 10 sequentially determines the presence or absence of the preceding vehicle V1 and executes automatic speed adjustment processing to control the drive unit (drive unit 30 and / or braking unit 40) based on the determination result. This function (automatic speed adjustment function) is also called adaptive cruise control (ACC). This function includes constant speed driving function and distance keeping function. The ECU 10 assigns a predetermined value to the target value (target acceleration αat) of the vehicle's acceleration α0 when accelerating during the automatic speed adjustment processing. On the other hand, the ECU 10 assigns a predetermined value to the target value (target deceleration αdt) of the vehicle's acceleration α0 when decelerating during the automatic speed adjustment processing. In this embodiment, the magnitude (absolute value) of the target acceleration αat and the magnitude (absolute value) of the target deceleration αdt are set to be the same. However, the magnitudes of the two can be different.

[0041] (Cruise control function)

[0042] The ECU 10 determines the presence of a preceding vehicle V1 based on information obtained from front sensors (millimeter-wave radar 21, sonar 22, and camera 23). If the preceding vehicle V1 is not present, the ECU 10 performs constant speed driving. Specifically, the ECU 10 assigns a target value (target speed spt) to the vehicle's speed sp0, set by the driver as the upper limit value spmax. Furthermore, the ECU 10 controls the drive system to match the speed sp0 with 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 to match the vehicle's acceleration α0 with the target acceleration αat. This process is referred to as "automatic acceleration processing." On the other hand, if the vehicle's speed sp0 is higher than the target speed spt, the ECU 10 controls the drive system to match the vehicle's acceleration α0 (deceleration) with the target deceleration αdt. This process is referred to as "automatic deceleration processing." Thus, the vehicle's speed sp0 approaches the target speed spt (= spmax). In addition, even if there is a preceding vehicle V1, if its speed sp1 is greater than the upper limit value spmax, ECU10 will perform constant speed driving control.

[0043] [Workshop Distance Maintenance Control]

[0044] On the other hand, when ECU 10 determines that a preceding vehicle V1 exists and the speed sp1 of the preceding vehicle V1 is less than the upper limit value spmax, it performs a vehicle-to-vehicle distance maintenance process. Specifically, ECU 10 obtains the vehicle-to-vehicle distance D between the preceding vehicle V1 and its own vehicle based on information acquired from the on-board sensor 20. Furthermore, ECU 10 assigns a predetermined value to a target value (target vehicle-to-vehicle distance Dt) for the vehicle-to-vehicle distance D. ECU 10 controls the drive unit, etc., to make the vehicle-to-vehicle distance D consistent with the target value (target vehicle-to-vehicle distance Dt).

[0045] When the speed sp1 of the preceding vehicle V1 (relative speed spr = sp1 - sp0) is greater than 0 relative to the speed sp0 of the current vehicle, the inter-vehicle distance D increases. When the inter-vehicle distance D is greater than the target inter-vehicle distance Dt, the ECU 10 accelerates the current vehicle so that its speed sp0 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. Furthermore, the ECU 10 controls the drive system, etc., to make the current vehicle's acceleration α0 match the target acceleration αat (automatic acceleration processing). As a result, the inter-vehicle distance D decreases, approaching the target inter-vehicle distance Dt. The ECU 10 controls the drive system, etc., to make the current vehicle travel at the same speed as the preceding vehicle V1 from the moment the inter-vehicle distance D matches the target inter-vehicle distance Dt.

[0046] On the other hand, when the relative speed spr is less than 0, the vehicle distance D decreases. When the vehicle distance D is less than the target vehicle distance Dt, the ECU 10 decelerates the vehicle. That is, the ECU 10 assigns a predetermined value to the target deceleration αdt. Furthermore, the ECU 10 controls the drive system (automatic deceleration processing) to make the vehicle's acceleration α0 (measured value) match the target deceleration αdt. As a result, the vehicle distance D increases, approaching the target vehicle distance Dt. Moreover, the drive system is controlled to ensure that the vehicle travels at the same speed as the preceding vehicle V1 from the moment the vehicle distance D matches the target vehicle distance Dt.

[0047] Furthermore, the target inter-vehicle distance Dt is related to the speed sp0 of this vehicle and the speed sp1 of the preceding vehicle V1. For example, the target inter-vehicle distance Dta is smaller when sp0 and sp1 are smaller than when sp0 and sp1 are larger. A database (table) representing the relationship between speeds sp0, sp1 and the target inter-vehicle distance Dt, or an expression used to calculate the target inter-vehicle distance Dt, is stored in ROM10b. ECU10 determines the target inter-vehicle distance Dt based on the aforementioned database or expression.

[0048] When a trailer T is attached to the vehicle, the overall vehicle weight is relatively large. Generally, the inertial force acting on the vehicle (both the vehicle and the trailer T) is greater when the vehicle is heavy (attached to the trailer T) compared to when the vehicle is light (without the trailer T attached). Therefore, when the vehicle is connected to the trailer T and the automatic speed control accelerates the vehicle, if the acceleration is large, an overshoot may temporarily occur after the speed sp0 reaches the target speed spt. Conversely, when the vehicle is decelerated by the automatic speed control, if the deceleration (absolute value) is large, an undershoot may temporarily occur after the speed sp0 reaches the target speed spt. This overshoot or undershoot of speed sp0 relative to the target speed spt (due to repeated acceleration and deceleration within a short period) impairs passenger comfort.

[0049] Furthermore, when the vehicle is connected to the trailer T, automatic speed adjustment accelerates the vehicle. If the vehicle's acceleration is relatively large, under-adjustment may occur, where the vehicle's distance to the trailer decreases and reaches the target distance Dt, but then temporarily falls below the target distance Dt. In this situation, the vehicle approaches the preceding vehicle V1 excessively, increasing passenger anxiety and potentially compromising passenger comfort.

[0050] Furthermore, when the vehicle is heavy, greater driving force is required to accelerate it, which sometimes results in higher engine speeds. In this situation, the engine noise is loud, compromising passenger comfort.

[0051] Therefore, ECU10 determines whether the trailer T is connected to the vehicle (whether the vehicle weight is high), and determines the values ​​to be allocated to the target acceleration αat, target deceleration αdt, and target inter-vehicle distance Dt based on this determination. Specifically, ECU10 (CPU10a) monitors the logic level of input port IN. When the logic level of input port IN is "H" (when no trailer T is connected to the vehicle (first state)), it allocates the larger absolute value αa1 (>αa2) to the target acceleration αat and the larger absolute value αd1 (=-αa1) to the target deceleration αdt. In this case, ECU10 allocates the smaller absolute 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" (in the case of trailer T connection (second state)), ECU10 assigns the smaller absolute value αa2 (< αa1) to the target acceleration αat, and assigns the smaller absolute value αd2 (= -αa2) to the target deceleration αdt. Furthermore, in this case, ECU10 assigns the larger absolute value D2 (> D1) to the target inter-vehicle distance Dt.

[0052] 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. Furthermore, the wire W1 may break due to this vibration. In this case, the logic level of the input port IN transitions from "L" to "H". Therefore, ECU 10 determines that although the trailer T is connected to the vehicle, it is not actually connected. In this scenario, assuming that ECU 10 assigns the specified values ​​αa1 and αd1 to the target acceleration αat and target deceleration αdt respectively, and assigns the specified value D1 to the target inter-vehicle distance Dt, an overshoot or undershoot occurs in the speed sp0 (measured value) relative to the target speed spt. Furthermore, in this case, an overshoot or undershoot occurs in the inter-vehicle distance D (measured value) relative to the target inter-vehicle distance Dt. Also, the engine speed of the vehicle may become relatively high. Furthermore, the driver may need to manually correct the acceleration α0 and the inter-vehicle distance D.

[0053] Therefore, ECU10 acquires the logic level of input port IN after the ignition switch of the vehicle transitions from the off state to the on state and before the vehicle starts moving. If the logic level is "L" and then transitions to "H" after the vehicle and trailer T start moving, there is a high probability that connectors Pa and Pb will detach from sockets Sa and Sb, or that wire W1 will break. Therefore, in this case, ECU10 assigns a smaller absolute value αa3 (< αa1) to the target acceleration αat and target deceleration αdt, and a smaller absolute value αd3 (=-αa3) to the target deceleration αdt. That is, ECU10 controls the vehicle to make the rate of change of vehicle speed relatively slow. Furthermore, in this case, ECU10 assigns a larger absolute value D3 (> D1) to the target inter-vehicle distance Dt. Here, the absolute values ​​of the absolute values ​​αa3 and αd3 can be equal to the absolute values ​​of the absolute values ​​αa2 and αd2. Also, the absolute value D3 can be equal to the absolute value D2. Additionally, if the ECU10 determines that the vehicle is about to start when the ignition switch is just turned on and the gear position is "P (Park)". Then, if the gear position is turned to "D (Drive)" or "R (Reverse)", it determines that the vehicle has started.

[0054] Next, refer to Figure 3 The program PR1 executed by the CPU10a (hereinafter referred to as "CPU") of the ECU10 in order to realize the function of the driving assistance device 1, namely, to determine the values ​​of the target acceleration αat, target deceleration αdt, and target inter-vehicle distance Dt based on the determination result of the connection state between the vehicle and the trailer T, will be described. The CPU starts executing program PR1 when the ignition switch of the vehicle transitions from the off state to the on state.

[0055] (Program PR1)

[0056] The CPU starts executing program PR1 from step 100 and proceeds to step 101.

[0057] In step 101, the CPU determines whether the vehicle is in a state after the ignition switch has transitioned to the ON state and before it starts moving (whether the gear shift position is "P"). If the CPU determines that the vehicle is in a state before it starts moving (101: Yes), it proceeds to step 102. On the other hand, if the CPU does not determine that the vehicle is in a state before it starts moving (101: No), it proceeds to step 105, which will be described later.

[0058] In step 102, the CPU determines whether the logic level of input port IN is "H". If the CPU determines that the logic 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 logic level of input port IN is "H" (102: No), it proceeds to step 104.

[0059] In step 103, the CPU assigns the predetermined values ​​αa1 and αd1 to the target acceleration αat and target deceleration αdt, respectively, and assigns the predetermined value D1 to the target inter-vehicle distance Dt. Then, the CPU returns to step 101.

[0060] In step 104, the CPU assigns the specified values ​​αa2 and αd2 to the target acceleration αat and target deceleration αdt, respectively, and assigns the specified value D2 to the target inter-vehicle distance Dt. Then, the CPU returns to step 101.

[0061] In step 105, the CPU determines whether the logic level of input port IN has transitioned from "L" to "H". If the CPU determines that the logic 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 logic level of input port IN has transitioned from "L" to "H" (105: No), it returns to step 101.

[0062] In step 106, the CPU assigns the specified values ​​αa3 and αd3 to the target acceleration αat and target deceleration αdt, respectively, and assigns the specified value D3 to the target inter-vehicle distance Dt. Then, the CPU returns to step 101.

[0063] (Effect)

[0064] While the vehicle is traveling with a trailer T attached to it, the trailer T is rarely intentionally disconnected from the vehicle. Therefore, when the ECU 10 of the driving assistance device 1 according to this embodiment detects a transition from the second state (attached state) to the first state (disconnected state) during travel, it controls the vehicle (drive unit 30) to make the vehicle's acceleration α0 relatively slow (in the same manner as in the second state), and controls the vehicle (drive unit 30 and / or braking device 40) to make the inter-vehicle distance D relatively large (in the same manner as in the second state). Therefore, the need for the driver to manually correct speed and inter-vehicle distance is low. Furthermore, the increase in occupant anxiety about vehicle behavior is suppressed. Therefore, the decrease in occupant comfort is suppressed.

[0065] (Variation example)

[0066] The structure used to determine the connection status between the vehicle and the trailer T is not limited to the structure described above. For example, if the communication interruption between the ECU10 and the brake ECU51 via the CAN port lasts for more than a threshold time, it can be determined that the vehicle and the trailer T are not connected.

[0067] Symbol Explanation

[0068] 1-Driver assistance device, 10-ECU, 20-On-board sensor, 30-Drive device, 40-Brake device, T-Trailer, V0-Vehicle (this vehicle).

Claims

1. A driving assistance device, characterized in that, The system includes a processor configured to perform automatic speed adjustment processing, which controls the drive and / or braking devices of the vehicle to automatically adjust the speed of the vehicle capable of towing a trailer. The automatic speed adjustment processing includes: controlling the drive and / or braking devices to ensure that the rate of change of speed of the vehicle during acceleration and deceleration matches a predetermined target value; and, when a preceding vehicle is present, controlling the drive and / or braking devices to ensure that the distance between the vehicle and the preceding vehicle matches a predetermined target value. Furthermore, the system can detect the connection status between the vehicle and the trailer based on electrical signals input from electronic circuitry. The electronic circuit is a defined electronic circuit comprising: a first electronic circuit disposed in the vehicle; a second electronic circuit disposed in the trailer; and an electrical signal line connecting the first electronic circuit and the second electronic circuit. In a first state, where the vehicle and the trailer are not connected, a defined first speed change rate is assigned to a target value of the speed change rate, and a defined first inter-vehicle distance is assigned to a target value of the inter-vehicle distance. In a second state, where the vehicle and the trailer are connected, a defined second speed change rate, slower than the first speed change rate, is assigned to the target value of the speed change rate, and a second inter-vehicle distance, larger than the first inter-vehicle distance, is assigned to the target value of the inter-vehicle distance. Furthermore, the processor is configured such that, during the vehicle's operation, in a specific scenario where the transition from the second state to the first state is detected based on the electrical signal, a value slower than the first rate of change of speed is assigned to the target value of the rate of change of speed, and a value larger than the first inter-vehicle distance is assigned to the target value of the inter-vehicle distance.

2. The driving assistance device according to claim 1, characterized in that, The processor is configured to: in the specific scenario, assign the second rate of change of speed to a target value of the rate of change of speed, and assign the second workshop distance to a target value of the workshop distance.

3. The driving assistance device according to claim 1 or 2, characterized in that, The structure is as follows: The 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 wire connected to the first connector and the other end connected to the second connector, the voltage of the electrical signal reaches a predetermined first level. In the event that one end of the wire detaches from the first connector, the other end of the wire detaches from the second connector, or the wire breaks, the voltage of the electrical signal becomes a predetermined second voltage.

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