Control device and vehicle control system

Abstract

To provide a control device and a vehicle control system which highly accurately correct a temperature characteristic error of an acceleration sensor and calculate an inclination angle with improved accuracy.SOLUTION: A control device comprises: an acquisition section which is installed in the control device and acquires a sensing result of an acceleration sensor detecting acceleration of a vehicle; a calculation section which calculates an inclination angle on the basis of the sensing result; an estimation section which estimates a temperature around the acceleration sensor; an identification sensor which identifies a temperature characteristic error at the temperature on the basis of the estimated temperature around the acceleration sensor and temperature characteristic error information indicating a correspondence relation between the temperature around the acceleration sensor and the temperature characteristic error of individual acceleration sensor; a correction section which calculates a corrected inclination angle with an error of the inclination angle corrected on the basis of the identified temperature characteristic error; and an output section which outputs the corrected inclination angle to another device.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a control device and a vehicle control system. [Background technology]

[0002] 2. Description of the Related Art A conventional technique is known in which the inclination angle of the road on which the vehicle is traveling is calculated based on the output value of the vehicle's acceleration sensor, and control such as adjustment of the drive torque is performed in accordance with the calculated inclination angle. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-47626 Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, it is known that the measurement values ​​of the above-mentioned acceleration sensors contain measurement error (hereinafter also referred to as temperature characteristic error) that occurs due to changes in the ambient temperature of the acceleration sensor. It is empirically known that this temperature characteristic error differs for each individual acceleration sensor, and it is difficult to absorb the error by a method of correcting the measurement values ​​by setting a fixed correction coefficient.

[0005] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a control device and a vehicle control system that corrects the temperature characteristic error of an acceleration sensor with high precision and calculates the tilt angle more accurately. [Means for solving the problem]

[0006] In order to achieve the above-mentioned object, the control device of the present invention is provided with an acquisition unit that is provided in the control device and acquires sensing results from an acceleration sensor that detects vehicle acceleration, a calculation unit that calculates a tilt angle based on the sensing results, an estimation unit that estimates the ambient temperature of the acceleration sensor, an identification unit that identifies the temperature characteristic error at the estimated ambient temperature of the acceleration sensor based on temperature characteristic error information that represents the correspondence between the ambient temperature of the acceleration sensor and the temperature characteristic error of each individual acceleration sensor, a correction unit that calculates a corrected tilt angle by correcting the tilt angle error based on the identified temperature characteristic error, and an output unit that outputs the corrected tilt angle to another device. [Effects of the Invention]

[0007] According to the present invention, the temperature characteristic error of the acceleration sensor can be corrected with high precision, and the tilt angle can be calculated more accurately. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a block diagram showing an example of the configuration of the main parts of a vehicle equipped with a control device according to one embodiment of the present invention. [Figure 2] FIG. 2 is a block diagram showing an example of a functional configuration of a control device according to an embodiment of the present invention. [Figure 3] FIG. 3 is a diagram showing an example of temperature characteristic error information of the acceleration sensor according to one embodiment of the present invention. [Figure 4] FIG. 4 is a diagram illustrating an example of a method for generating temperature characteristic error information of an acceleration sensor according to an embodiment of the present invention. [Figure 5] FIG. 5 is a flowchart showing an example of processing executed by the control device according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0010] <Vehicle control system configuration> 1 is a block diagram showing an example of the configuration of a vehicle control system S. The vehicle control system S is a system that calculates the inclination angle of the road on which the vehicle is traveling and controls each part of the vehicle in accordance with the inclination angle. The vehicle control system S is mounted on a vehicle (not shown).

[0011] As shown in FIG. 1, the vehicle control system S includes a VSC (Vehicle Stability Control) ECU 1, a wheel speed sensor 2, an EFI (Electronic Fuel Injection) ECU 3, and a stereo camera ECU 4.

[0012] The VSCECU1, EFIECU3, and stereo camera ECU4 are connected to each other via a CAN (Controller Area Network) communication protocol to enable two-way communication. Note that the vehicle control system S may include ECUs other than the EFIECU3 and stereo camera ECU4.

[0013] The VSCECU1 is an example of a control device. The VSCECU1 is an ECU (Electronic Control Unit) that executes brake control of a vehicle (hereinafter also referred to as the host vehicle) equipped with the VSCECU1. For example, the VSCECU1 calculates the inclination angle of the road on which the host vehicle is traveling, and executes brake control according to the inclination angle. Furthermore, for example, the VSCECU1 transmits the calculated inclination angle to the EFIECU3 and the stereo camera ECU4.

[0014] The VSCECU1 is composed of a microcomputer including a CPU 10, RAM (not shown), ROM (not shown), and I / O (not shown), and a front-rear G sensor 11. The microcomputer may have a built-in nonvolatile memory such as a flash memory. The VSCECU1 may also have a G sensor other than the front-rear G sensor 11. The VSCECU1 may also have a temperature sensor that measures the temperature inside the VSCECU1.

[0015] The CPU 10 performs overall control of the operation of the VSCECU 1. The CPU 10 also executes a control program to realize each functional unit of the VSCECU 1. Each functional unit of the VSCECU 1 will be described later.

[0016] The longitudinal G sensor 11 is an example of an acceleration sensor. The longitudinal G sensor 11 detects acceleration in the longitudinal direction. The longitudinal G sensor 11 outputs a detection signal corresponding to the acceleration in the longitudinal direction to the CPU 10. The detection signal is used by the CPU 10 to calculate the inclination angle of the road on which the host vehicle is traveling. Note that the longitudinal G sensor 11 may be configured to include a first G sensor that detects acceleration in the forward direction of the host vehicle and a second G sensor that detects acceleration in the backward direction of the host vehicle.

[0017] The wheel speed sensors 2 detect the rotation speed of the wheels. A wheel speed sensor 2 is provided for each wheel. The wheel speed sensors 2 output detection signals (pulse signals synchronized with the rotation of the wheels) corresponding to the rotation speed of the wheels to the VSCECU1. The detection signals are used by the CPU 10 of the VSCECU1 to calculate the inclination angle of the road on which the vehicle is traveling.

[0018] An EFI (Electronic Fuel Injection) ECU 3 is an example of a vehicle control device. The EFI ECU 3 is a control device that controls the opening and closing of an engine throttle via an electronic throttle (not shown) in order to output a driving torque corresponding to an accelerator operation amount (accelerator opening) detected by an accelerator sensor (not shown). The EFI ECU 3 is configured by a microcomputer including a CPU, RAM, ROM, and I / O (none of which are shown).

[0019] For example, the EFIECU 3 receives the tilt angle calculated by the VSCECU 1 from the VSCECU 1 and performs control to adjust the drive torque according to the tilt angle. Also, for example, the EFIECU 3 receives a control signal based on the detection signal of the stereo camera from the stereo camera ECU 4.

[0020] The stereo camera ECU 4 is an example of a vehicle control device. The stereo camera ECU 4 is an ECU that controls the stereo camera provided in the host vehicle. Further, the stereo camera ECU 4 transmits a control signal based on the inclination angle of the traveling road of the host vehicle received from the VSC ECU 1 and the detection signal of the stereo camera to the EFI ECU 3.

[0021] The stereo camera ECU 4 is composed of a microcomputer including a CPU, a RAM, a ROM, and an I / O (none of which are shown). Further, the stereo camera ECU 4 is communicably connected to a stereo camera (not shown) provided in the host vehicle. The stereo camera is a distance measurement sensor composed of two cameras.

[0022] For example, the stereo camera ECU 4 detects the distance between the host vehicle and an obstacle existing in the traveling direction of the host vehicle based on the detection signal of the stereo camera. Further, for example, the stereo camera ECU 4 determines the possibility of a collision between the host vehicle and the obstacle based on the distance between the host vehicle and the obstacle.

[0023] When it is determined that there is a possibility of a collision between the host vehicle and the obstacle, the stereo camera ECU 4 outputs a control signal to cause the EFI ECU 3 to perform control to suppress the output of the driving torque with respect to the accelerator operation amount. Further, for example, when the inclination angle of the traveling road of the host vehicle received from the VSC ECU 1 is equal to or greater than a predetermined value, the stereo camera ECU 4 outputs a control signal to the EFI ECU 3 to cancel the control to suppress the output of the driving torque described above.

[0024] <Functional Configuration of VSC ECU> Next, the functional configuration of the VSC ECU 1 will be described. FIG. 2 is a block diagram showing an example of the functional configuration of the CPU 10 of the VSC ECU 1. The CPU 10 realizes each functional unit of the acquisition unit 101, the calculation unit 102, the estimation unit 103, the specification unit 104, the correction unit 105, and the output unit 106 by executing a control program stored in a ROM or the like.

[0025] The acquisition unit 101 acquires sensing results from various sensors provided in the vehicle. For example, the acquisition unit 101 acquires, as the sensing result, a detection signal corresponding to the rotation speed of the wheels from the wheel speed sensor 2. Also, for example, the acquisition unit 101 acquires, as the sensing result, a measurement value of the front / rear G sensor 11.

[0026] If the front-rear G sensor 11 is configured to include a first G sensor and a second G sensor, the acquisition unit 101 may acquire sensing results from each of the first G sensor and the second G sensor.

[0027] The calculation unit 102 calculates the inclination angle based on the sensing results of the wheel speed sensor 2 and the longitudinal G sensor 11. Specifically, the calculation unit 102 first calculates the vehicle speed of the host vehicle based on the sensing result of the wheel speed sensor 2. Then, the calculation unit 102 calculates the inclination angle of the road on which the host vehicle is traveling using the formula: inclination angle = measured value of the longitudinal G sensor 11 - d (vehicle speed) / dt.

[0028] In addition, if the front / rear G sensor 11 is configured to consist of a first G sensor and a second G sensor, the calculation unit 102 may calculate a first tilt angle based on the sensing result of the first G sensor and a second tilt angle based on the sensing result of the second G sensor.

[0029] The estimation unit 103 estimates the temperature around the longitudinal G sensor 11. For example, the estimation unit 103 estimates the temperature around the longitudinal G sensor 11 provided in the VSCECU1 based on the sensing result of a temperature sensor provided to measure the environmental temperature of the vehicle and a calculated value of the amount of heat estimated to be generated when the CPU 10 or the like of the VSCECU1 performs processing.

[0030] When the first tilt angle and the second tilt angle have been calculated by the calculation unit 102, the estimation unit 103 may estimate the temperature around the first G sensor and the temperature around the second G sensor.

[0031] Furthermore, if the VSCECU1 is configured to include a temperature sensor, the temperature sensor may be provided near the longitudinal G sensor 11 so that the acquisition unit 101 can directly acquire the temperature around the longitudinal G sensor 11. In this case, the VSCECU1 does not need to include the estimation unit 103.

[0032] The identification unit 104 identifies the estimated temperature characteristic error in the ambient temperature of the longitudinal G sensor 11 based on the estimated ambient temperature of the longitudinal G sensor 11 and a temperature characteristic error map that indicates the correspondence between the ambient temperature of the longitudinal G sensor 11 and the temperature characteristic error of each individual longitudinal G sensor 11. The temperature characteristic error map is an example of temperature characteristic error information.

[0033] When the first tilt angle and the second tilt angle have been calculated by the calculation unit 102, the identification unit 104 may identify the temperature characteristic error of the first G sensor and the temperature characteristic error of the second G sensor.

[0034] The temperature characteristic error MAP will now be described with reference to Fig. 3. Fig. 3 is a diagram showing an example of the temperature characteristic error MAP of the longitudinal G sensor 11. The temperature characteristic error MAP is information that represents the correspondence relationship between the ambient temperature of the longitudinal G sensor 11 and the measurement error (temperature characteristic error) of the longitudinal G sensor 11 at that temperature.

[0035] A temperature characteristic error MAP is provided for each individual G sensor. Therefore, if the longitudinal G sensor 11 is configured to include a first G sensor and a second G sensor, different temperature characteristic error MAPs are provided for the first G sensor and the second G sensor. The temperature characteristic error MAPs are stored, for example, in the ROM of the VSCECU1.

[0036] The temperature characteristic error MAP of FIG. 3 shows that, for example, when the ambient temperature of the longitudinal G sensor 11 is −40° C., the temperature characteristic error of the longitudinal G sensor 11 is 0.005 m / s 2 Furthermore, for example, when the temperature around the longitudinal G sensor 11 is 120° C., the temperature characteristic error of the longitudinal G sensor 11 is 0.02 m / s. 2 This indicates that...

[0037] Below, we will explain the process of identifying the temperature characteristic error of the longitudinal G sensor 11 by the identification unit 104 using the temperature characteristic error MAP of Figure 3, using an example where the ambient temperature of the longitudinal G sensor 11 estimated by the estimation unit 103 is 40°C.

[0038] In this case, the determination unit 104 refers to the temperature characteristic error map and determines that the temperature characteristic error is 0.01 m / s 2 is identified as the temperature characteristic error of the longitudinal G sensor 11 provided in the VSCECU1 at the estimated ambient temperature of the longitudinal G sensor 11.

[0039] Next, a method for generating the temperature characteristic error MAP will be described with reference to Fig. 4. Fig. 4 is a diagram illustrating an example of a method for generating the temperature characteristic error MAP of the longitudinal G sensor 11. The temperature characteristic error MAP is generated, for example, by utilizing an aging process included in the manufacturing process of the VSCECU1.

[0040] Here, the aging process is one of the inspections performed before shipping the VSCECU1. For example, in the aging process, the VSCECU1 is operated for a certain period of time in low-temperature and high-temperature environments to check for defects. In the aging process shown in Figure 4, the operation of the VSCECU1 is checked in environments at -40°C and 120°C.

[0041] At this time, the VSCECU1 can determine the temperature characteristic error at -40°C and the temperature characteristic error at 120°C by measuring the acceleration of an object moving at a known acceleration using the front-rear G sensor 11. The VSCECU1 stores the temperature characteristic error at -40°C and the temperature characteristic error at 120°C in a nonvolatile memory such as a flash memory.

[0042] Furthermore, it is known empirically that the relationship between the temperature of the G-sensor and the temperature characteristic error of the G-sensor is linear. Therefore, by linearly interpolating the stored temperature characteristic error at -40°C and the temperature characteristic error at 120°C, the VSCECU1 can generate a temperature characteristic error MAP, as shown in Fig. 3, which indicates the correspondence relationship between the ambient temperature of the front-rear G-sensor 11 and the temperature characteristic error of the front-rear G-sensor 11.

[0043] Note that an information processing device other than the VSCECU1 may be used to acquire information from the VSCECU1 and generate the temperature characteristic error MAP. In this case, the information processing device other than the VSCECU1 performs processing to store the temperature characteristic error MAP in a ROM or the like mounted on the VSCECU1.

[0044] The correction unit 105 calculates a corrected tilt angle by correcting the tilt angle error based on the identified temperature characteristic error. For example, the correction unit 105 calculates a tilt angle error that represents an error occurring in the tilt angle calculated by the calculation unit 102 based on the identified temperature characteristic error.

[0045] For example, the tilt angle error is calculated from the temperature characteristic error value of the front / rear G sensor 11. For example, the correction unit 105 subtracts the calculated tilt angle error from the tilt angle calculated by the calculation unit 102 to calculate a corrected tilt angle.

[0046] When the first tilt angle and the second tilt angle are calculated by the calculation unit 102, the correction unit 105 may calculate a first corrected tilt angle by correcting the first tilt angle and a second corrected tilt angle by correcting the second tilt angle. The correction unit 105 may also calculate the corrected tilt angle using the formula: corrected tilt angle = (measurement value of the front / rear G sensor 11 - specified temperature characteristic error) - d (vehicle speed) / dt.

[0047] The output unit 106 outputs the corrected tilt angle to a device other than the VSCECU 1. For example, the output unit 106 transmits the calculated corrected tilt angle to the EFIECU 3 and the stereo camera ECU 4 via an I / O.

[0048] In addition, when the correction unit 105 calculates the first correction inclination angle and the second correction inclination angle, the output unit 106 may output both the first correction inclination angle and the second correction inclination angle.

[0049] Then, the EFI ECU 3 and the stereo camera ECU 4 that have received the correction inclination angle perform a process of controlling each part of the host vehicle according to the correction inclination angle. In this case, the CPUs of the EFI ECU 3 and the stereo camera ECU 4 are examples of the receiving unit and the control unit of the vehicle control device.

[0050] <Processing of VSCECU> Next, the process executed by the VSCECU 1 of the vehicle control system S will be described. FIG. 5 is a flowchart showing an example of the process executed by the CPU 10 of the VSCECU 1.

[0051] First, the acquisition unit 101 acquires the sensing results of various sensors provided in the host vehicle (step S1). Specifically, the sensing results are acquired from the wheel speed sensor 2, the front and rear G sensors 11, and the temperature sensor for measuring the ambient temperature of the host vehicle.

[0052] Next, the calculation unit 102 calculates the inclination angle of the traveling road of the host vehicle (step S2). Specifically, the calculation unit 102 calculates the vehicle speed of the host vehicle based on the detection signal acquired from the wheel speed sensor 2. The calculation unit 102 calculates the inclination angle of the traveling road of the host vehicle based on the measured value acquired as the sensing result from the front and rear G sensors 11 and the calculated vehicle speed.

[0053] Next, the estimation unit 103 estimates the temperature around the front and rear G sensors 11 (step S3). Specifically, the estimation unit 103 estimates the temperature around the front and rear G sensors 11 based on the measured value of the temperature sensor for measuring the ambient temperature of the host vehicle and the calculated value of the amount of heat generated when the VSCECU 1 executes the process. [[ID=2�]]

[0054] Next, the identification unit 104 identifies (step S4) the temperature characteristic error at the estimated ambient temperature of the longitudinal G sensor 11. Specifically, the identification unit 104 refers to the temperature characteristic error MAP of the longitudinal G sensor 11, and identifies the temperature characteristic error corresponding to the estimated ambient temperature of the longitudinal G sensor 11 as the temperature characteristic error of the longitudinal G sensor 11 at that temperature.

[0055] Next, the correction unit 105 corrects the calculated tilt angle and calculates a corrected tilt angle (step S5). Specifically, the correction unit 105 calculates a tilt angle error based on the identified temperature characteristic error. The correction unit 105 calculates the corrected tilt angle based on the calculated tilt angle and the calculated tilt angle error.

[0056] Next, the output unit 106 outputs the corrected tilt angle (step S6). Specifically, the output unit 106 transmits the calculated corrected tilt angle to the EFIECU 3 and the stereo camera ECU 4 via the I / O, and then ends this process.

[0057] <Action and effect> As described above, the VSCECU1 according to this embodiment estimates the ambient temperature of the front-rear G sensor 11 provided in the VSCECU1 and detecting the acceleration of the vehicle, and can identify the temperature characteristic error of the front-rear G sensor 11 at that temperature based on the temperature characteristic error MAP that represents the correspondence between the ambient temperature of the front-rear G sensor 11 and the temperature characteristic error of each individual front-rear G sensor 11.

[0058] Because the temperature characteristic error MAP is provided for each individual G sensor, the VSCECU1 according to this embodiment can identify the temperature characteristic error of the longitudinal G sensor 11 mounted on the vehicle without being affected by individual differences between G sensors. Furthermore, the VSCECU1 according to this embodiment can correct the tilt angle calculated based on the sensing results of the longitudinal G sensor 11 based on the identified temperature characteristic error of the longitudinal G sensor 11. In other words, the VSCECU1 according to this embodiment can correct the temperature characteristic error of the longitudinal G sensor 11 with high precision and calculate the tilt angle more accurately.

[0059] Furthermore, the longitudinal G sensor 11 provided in the VSCECU 1 may be configured to include a first G sensor that detects the acceleration of the host vehicle in the forward direction, and a second G sensor that detects the acceleration of the host vehicle in the backward direction.

[0060] In this case, different temperature characteristic error MAPs are provided for the first G sensor and the second G sensor, so the VSCECU1 can identify the temperature characteristic error of the first G sensor at the estimated ambient temperature of the first G sensor and the temperature characteristic error of the second G sensor at the estimated ambient temperature of the second G sensor. Therefore, the VSCECU1 can highly accurately correct the temperature characteristic error of the G sensor for both the tilt angle calculated based on the forward acceleration and the tilt angle calculated based on the backward acceleration, thereby more accurately calculating the tilt angle.

[0061] In addition, the temperature characteristic error MAP according to this embodiment is generated based on the temperature characteristic error of the front-rear G sensor 11 measured in a low temperature environment (e.g., -40°C) and the temperature characteristic error of the front-rear G sensor 11 measured in a high temperature environment (e.g., 120°C).

[0062] As a result, for example, if the aging process, which is one of the inspection processes before shipping the VSCECU1, is performed in a low-temperature environment and a high-temperature environment, the temperature characteristic error MAP can be generated in the aging process. Therefore, the temperature characteristic error MAP can be generated without incurring large costs.

[0063] In addition, various design modifications can be made to the above-described configuration within the scope of the claims. [Explanation of symbols]

[0064] 1:VSCECU 10:CPU 101: Acquisition Department 102: Calculation unit 103: Estimation part 104: Specific part 105: Correction unit 106: Output section 11: Front and rear G sensors 2: Wheel speed sensor 3:EFIECU 4: Stereo camera ECU

Claims

1. an acquisition unit provided in the control device and configured to acquire a sensing result from an acceleration sensor that detects the acceleration of the vehicle; a calculation unit that calculates an inclination angle based on the sensing result; an estimation unit that estimates the ambient temperature of the acceleration sensor; an identification unit that identifies the temperature characteristic error at the temperature based on the estimated ambient temperature of the acceleration sensor and temperature characteristic error information that indicates a correspondence relationship between the ambient temperature of the acceleration sensor and the temperature characteristic error of each individual acceleration sensor; a correction unit that calculates a corrected tilt angle by correcting the tilt angle error based on the identified temperature characteristic error; an output unit that outputs the corrected tilt angle to another device; A control device comprising:

2. the acquisition unit acquires a first sensing result from a first acceleration sensor that is the acceleration sensor that detects acceleration on a front side of the vehicle, and acquires a second sensing result from a second acceleration sensor that is the acceleration sensor on a rear side of the vehicle; the calculation unit calculates a first tilt angle based on a first sensing result and a second tilt angle based on a second sensing result; the estimation unit estimates an ambient temperature of the first acceleration sensor and an ambient temperature of the second acceleration sensor; the specifying unit specifies a temperature characteristic error of the first acceleration sensor and a temperature characteristic error of the second acceleration sensor; the correction unit calculates a first corrected tilt angle by correcting an error in the first tilt angle and a second corrected tilt angle by correcting an error in the second tilt angle. The control device according to claim 1 .

3. the first acceleration sensor and the second acceleration sensor each have different temperature characteristic error information; The control device according to claim 2 .

4. the temperature characteristic error information is generated based on a temperature characteristic error of the acceleration sensor measured at a first temperature and a temperature characteristic error of the acceleration sensor measured at a second temperature different from the first temperature; The control device according to any one of claims 1 to 3.

5. A vehicle control system comprising the control device according to any one of claims 1 to 4 and at least one vehicle control device different from the control device, The vehicle control device includes: a receiving unit that receives the corrected tilt angle; a control unit that performs control based on the received corrected tilt angle; Equipped with Vehicle control system.

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