Parking assistance device, parking assistance method, and computer-readable storage medium

Abstract

The present application provides a parking assistance device, a parking assistance method, and a computer readable storage medium, which improve the recognition accuracy of the inclination angle of the ground during parking assistance. The parking assistance device of the embodiment includes: an inclination angle calculation unit that calculates information indicating the inclination angle of the ground on which the vehicle is traveling, i.e., first inclination angle information, according to a time series, and calculates second inclination angle information by performing filter processing that removes high-frequency components above a prescribed threshold on waveform information represented by a plurality of first inclination angle information calculated according to the time series, and in a case where it is determined based on a prescribed criterion that there is a deviation between the first inclination angle information and the second inclination angle information, resets the plurality of first inclination angle information used in the filter processing, and calculates the second inclination angle information by performing filter processing using the plurality of first inclination angle information calculated after the reset; and a movement control unit that adjusts the driving force and the braking force according to the second inclination angle information.

Description

Technical Field

[0001] This invention relates to parking assistance devices, parking assistance methods, and computer-readable storage media. Background Technology

[0002] Previously, as a parking assist technology, there was a technology that, while controlling the vehicle to move to the target parking position, adjusted the driving force and braking force of the vehicle based on the tilt angle of the ground on which the vehicle was traveling.

[0003] However, for example, if the information about the tilt angle of the ground detected by the vehicle includes high-frequency noise, filtering to remove this noise will delay the recognition of the tilt angle. This can lead to problems, for example, if the parking target location is on a slope transitioning from uphill to downhill, the vehicle may become faster than expected just before reaching the target parking location, requiring emergency braking to stop at the target parking position. Summary of the Invention

[0004] Therefore, one of the objectives of this invention is to obtain a parking assist device, a parking assist method, and a computer-readable storage medium that can improve the accuracy of recognizing the tilt angle of the ground during parking assistance.

[0005] The parking assist device of the embodiment includes, for example: a path calculation unit that calculates a movement path for moving the vehicle from its current position to a parking target position; a tilt angle calculation unit that calculates information representing the tilt angle of the ground on which the vehicle is traveling, i.e., first tilt angle information, based on a time series, and performs filtering processing on waveform information represented by multiple first tilt angle information calculated based on the time series to remove high-frequency components above a predetermined threshold to calculate second tilt angle information; if it is determined based on a predetermined criterion that there is a deviation between the first tilt angle information and the second tilt angle information, the multiple first tilt angle information used in the filtering processing is reset, and the filtering processing is performed using the multiple first tilt angle information calculated after the reset to calculate the second tilt angle information; and a movement control unit that performs movement control to control the driving force and braking force of the vehicle to move the vehicle along the movement path to the parking target position, and adjusts the driving force and braking force based on the second tilt angle information.

[0006] According to such a parking assist device, for example, if a deviation is determined between the first tilt angle information and the second tilt angle information, by resetting the multiple first tilt angle information used in the filtering process, the subsequently calculated second tilt angle information can catch up with the true value earlier. In other words, the accuracy of recognizing the tilt angle of the ground during parking assistance can be improved.

[0007] Furthermore, in the aforementioned parking assist device, for example, if the tilt angle calculation unit determines, based on the aforementioned predetermined benchmark, that there is a deviation between the first tilt angle information and the second tilt angle information for a period of time or longer, it resets the plurality of first tilt angle information used in the aforementioned filtering process.

[0008] With such a parking assist device, for example, by performing the reset if the time in which the deviation is determined to exist continues for more than a specified period of time, accidental resets can be prevented more reliably.

[0009] Furthermore, in the aforementioned parking assist device, for example, if the tilt angle calculation unit resets the multiple first tilt angle information used in the aforementioned filtering process, the movement control unit uses the first tilt angle information instead of the second tilt angle information to perform the aforementioned movement control after the reset until the tilt angle calculation unit begins calculating the second tilt angle information.

[0010] According to such a parking assist device, for example, by using the first tilt angle information instead of the second tilt angle information after the reset until the second tilt angle information is calculated, movement control can be continuously performed.

[0011] Furthermore, in the aforementioned parking assist device, for example, when the tilt angle calculation unit resets the plurality of the first tilt angle information used in the aforementioned filtering process, the movement control unit immediately after the reset performs the aforementioned movement control using predetermined tilt angle information obtained based on the plurality of the first tilt angle information calculated by the tilt angle calculation unit before the reset.

[0012] According to such a parking assist device, for example, by obtaining a specified tilt angle information based on multiple first tilt angle information calculated before the reset immediately following the reset, and using the specified tilt angle information, more appropriate movement control can be performed.

[0013] Additionally, the parking assistance method of the embodiment includes: a path calculation step, which calculates a movement path for moving the vehicle from its current position to a parking target position; a tilt angle calculation step, which calculates information representing the tilt angle of the ground on which the vehicle is traveling, i.e., first tilt angle information, based on a time series, and performs filtering processing on waveform information represented by multiple first tilt angle information calculated based on the time series to remove high-frequency components above a predetermined threshold to calculate second tilt angle information; if it is determined based on a predetermined benchmark that there is a deviation between the first tilt angle information and the second tilt angle information, the multiple first tilt angle information used in the filtering processing is reset, and the multiple first tilt angle information calculated after the reset is used to perform the filtering processing to calculate the second tilt angle information; and a movement control step, which executes movement control to control the driving force and braking force of the vehicle to move the vehicle along the movement path to the parking target position, and at this time, adjusts the driving force and the braking force based on the second tilt angle information.

[0014] According to such a parking assistance method, for example, by resetting multiple first tilt angle information used in the filtering process when it is determined that there is a deviation between the first tilt angle information and the second tilt angle information, the second tilt angle information calculated later can follow the true value earlier.

[0015] Furthermore, the computer-readable storage medium of the embodiment stores a computer program that enables the computer to function as the following components: a path calculation unit that calculates a movement path for moving the vehicle from its current position to a parking target position; a tilt angle calculation unit that calculates information representing the tilt angle of the ground on which the vehicle is traveling, i.e., first tilt angle information, based on a time series, and performs filtering processing on waveform information represented by multiple first tilt angle information calculated based on the time series to remove high-frequency components above a predetermined threshold to calculate second tilt angle information; if it is determined based on a predetermined criterion that there is a deviation between the first tilt angle information and the second tilt angle information, the multiple first tilt angle information used in the filtering processing is reset, and the filtering processing is performed using the reset multiple first tilt angle information to calculate the second tilt angle information; and a movement control unit that executes movement control to control the driving force and braking force of the vehicle to move the vehicle along the movement path to the parking target position, and adjusts the driving force and braking force based on the second tilt angle information.

[0016] Based on such a computer-readable storage medium, for example, by resetting multiple first tilt angle information used in the filtering process when it is determined that there is a deviation between the first tilt angle information and the second tilt angle information, it is possible to make the second tilt angle information calculated subsequently follow the true value earlier. Attached Figure Description

[0017] Figure 1 This is a top view of a vehicle equipped with a parking assist system implemented thereon.

[0018] Figure 2 This is a block diagram showing the overall configuration of the parking assist system according to the implementation method.

[0019] Figure 3 This is a functional block diagram used to explain the functions of the parking assist device in the implementation method.

[0020] Figure 4 This is a diagram illustrating an example of road inclination during a parking assist implementation.

[0021] Figure 5 This is a chart related to the tilt angle in the parking assist of the comparative example.

[0022] Figure 6 This is a graph related to the tilt angle in the parking assist implementation.

[0023] Figure 7 This is a flowchart of the parking assistance process performed by the parking assistance device in the implementation method.

[0024] Figure 8 It means Figure 7 A detailed flowchart of step S4 in the process.

[0025] Explanation of reference numerals in the attached figures

[0026] 10…Vehicle, 31…Acceleration sensor, 34…Parking assist device, 71…Acquisition unit, 72…Detection unit, 73…Operation receiving unit, 74…Parking assist unit, 74a…Target position calculation unit, 74b…Path calculation unit, 74c…Tilt angle calculation unit, 74d…Movement control unit, 75…Tilt angle storage unit. Detailed Implementation

[0027] The following describes exemplary embodiments of the present invention. The configuration of the embodiments shown below, as well as the effects, results, and outcomes resulting from such configurations, are examples. The present invention can also be implemented with configurations other than those disclosed in the following embodiments, and at least one of various effects and derivative effects based on the basic configuration can be obtained.

[0028] Figure 1It is a parking assist system 20 equipped with an implementation method. Figure 2 This is a top view of vehicle 10. Vehicle 10 can be, for example, an automobile powered by an internal combustion engine (engine, not shown) (internal combustion engine vehicle), an automobile powered by an electric motor (motor, not shown) (electric vehicle, fuel cell vehicle, etc.), or an automobile powered by both (hybrid vehicle). Furthermore, vehicle 10 can be equipped with various transmission devices, as well as various devices (systems, components, etc.) required to drive the internal combustion engine and electric motor. Additionally, the method, number, and layout of devices related to the drive of the wheels 13 in vehicle 10 can be variously configured.

[0029] like Figure 1 As shown, the vehicle 10 includes a body 12, four wheels 13, four camera units 14a-14d, and twelve rangefinder units 16a-16l. Hereinafter, camera units 14a-14d will be referred to as camera unit 14 unless it is necessary to distinguish them. Similarly, rangefinder units 16a-16l will be referred to as rangefinder units 16 unless it is necessary to distinguish them.

[0030] The car body 12 constitutes the passenger compartment. The car body 12 houses or retains the wheels 13, the camera unit 14, the rangefinder unit 16, etc.

[0031] Four wheels 13 are located at the front, rear, left, and right of the vehicle body 12. For example, the two front wheels 13 function as steering wheels, and the two rear wheels 13 function as drive wheels.

[0032] The imaging unit 14 is, for example, a digital camera with built-in imaging elements such as a CCD (Charge Coupled Device) or a CIS (CMOS Image Sensor). The imaging unit 14 outputs data of the captured image, including data of animation or still images that include multiple frames generated at a specified frame rate.

[0033] The ranging unit 16 is, for example, installed on the outer periphery of the vehicle 10, and transmits sound waves, including ultrasonic waves, as detection waves to capture detection waves reflected by other vehicles or other objects present around the vehicle 10. Alternatively, the ranging unit 16 can also be a radar, millimeter-wave radar, or the like that outputs detection waves such as lasers.

[0034] Figure 2 This is a block diagram showing the overall configuration of the parking assistance system 20 according to the implementation method. The parking assistance system 20 is mounted on the vehicle 10 and assists the driving of the vehicle 10 through automatic driving (including partial automatic driving) based on objects around the vehicle 10.

[0035] like Figure 2As shown, the parking assist system 20 includes a camera unit 14, a distance measuring unit 16, a braking system 22, an acceleration system 24, a steering control system 26, a transmission system 28, a vehicle speed sensor 30, an acceleration sensor 31, a monitoring device 32, a parking assist device 34, and an in-vehicle network 36.

[0036] The braking system 22 controls the deceleration of the vehicle 10. The braking system 22 includes a braking unit 40, a braking control unit 42, and a braking unit sensor 44.

[0037] The braking unit 40 is, for example, a device that includes a brake and a brake pedal, for decelerating the vehicle 10.

[0038] The braking control unit 42 is, for example, a computer such as a microcomputer with a hardware processor such as a CPU (Central Processing Unit). The braking control unit 42 controls the braking unit 40 based on the instructions from the parking assist device 34 to control the deceleration of the vehicle 10.

[0039] Brake sensor 44, for example, is a position sensor that detects the position of brake unit 40 when brake unit 40 is the brake pedal. Brake sensor 44 outputs the detected position of brake unit 40 to vehicle network 36.

[0040] The acceleration system 24 controls the acceleration of the vehicle 10. The acceleration system 24 includes an acceleration unit 46, an acceleration control unit 48, and an acceleration sensor 50.

[0041] Acceleration unit 46 includes, for example, an accelerator pedal or other device for accelerating the vehicle 10.

[0042] The acceleration control unit 48 is, for example, a computer such as a microcomputer with a hardware processor such as a CPU. The acceleration control unit 48 controls the acceleration unit 46 based on instructions from the parking assist device 34 to control the acceleration of the vehicle 10.

[0043] Acceleration sensor 50, for example, is a position sensor that detects the position of acceleration unit 46 when acceleration unit 46 is an accelerator pedal. Acceleration sensor 50 outputs the detected position of acceleration unit 46 to in-vehicle network 36.

[0044] The steering system 26 controls the direction of travel of the vehicle 10. The steering system 26 includes a steering control unit 52, a steering control unit 54, and a steering control unit sensor 56.

[0045] The steering control unit 52 is, for example, a handle or steering wheel, which is a device that turns the steering wheels of the vehicle 10 and controls the direction of travel of the vehicle 10.

[0046] The steering control unit 54 is, for example, a computer such as a microcomputer with a hardware processor such as a CPU. The steering control unit 54 controls the steering unit 52 based on instructions from the parking assist device 34 to control the direction of travel of the vehicle 10.

[0047] The steering control sensor 56 is, for example, an angle sensor including a Hall element, which detects the rotation angle of the steering control unit 52, i.e., the steering angle. The steering control sensor 56 outputs the detected steering angle of the steering control unit 52 to the vehicle network 36.

[0048] The transmission system 28 controls the gear ratio of the vehicle 10. The transmission system 28 includes a transmission unit 58, a transmission control unit 60, and a transmission unit sensor 62.

[0049] The transmission unit 58 is, for example, a device that includes a gear lever or the like, to change the gear ratio of the vehicle 10.

[0050] The transmission control unit 60 is, for example, a computer such as a microcomputer with a hardware processor such as a CPU. The transmission control unit 60 controls the transmission unit 58 based on the instructions from the parking assist device 34 to control the transmission ratio of the vehicle 10.

[0051] The transmission sensor 62 is, for example, a position sensor, which detects the position of the transmission unit 58 when the transmission unit 58 is a gear lever. The transmission sensor 62 outputs the detected position of the transmission unit 58 to the vehicle network 36.

[0052] The vehicle speed sensor 30 is, for example, a sensor with a Hall element located near the wheel 13 of the vehicle 10, that detects the amount of rotation of the wheel 13 or the rotational speed per unit time. The vehicle speed sensor 30 outputs the number of wheel speed pulses, representing the detected amount of rotation or rotational speed, as a sensor value for calculating the vehicle speed to the in-vehicle network 36. The parking assist device 34 can calculate the speed (vehicle speed), amount of movement, etc. of the vehicle 10 based on the sensor value obtained from the vehicle speed sensor 30.

[0053] Accelerometer 31 is, for example, a capacitive 3-axis accelerometer that detects acceleration caused by gravity, acceleration or deceleration of vehicle 10, etc. Accelerometer 31 outputs an acceleration signal representing the detection result. Parking assist device 34 can calculate the tilt angle of the ground on which vehicle 10 is traveling based, for example, the acceleration signal obtained from accelerometer 31.

[0054] The monitoring device 32 is installed in the dashboard or other parts inside the passenger compartment of the vehicle 10. The monitoring device 32 includes a display unit 64, a sound output unit 66, and an operation input unit 68.

[0055] Display unit 64 displays images based on the images sent by parking assist device 34. Display unit 64 is, for example, a liquid crystal display (LCD) or an organic electroluminescent display (OELD). Display unit 64 displays, for example, images indicating the switching between automatic and manual driving.

[0056] The sound output unit 66 outputs sound based on the sound data sent by the parking assist device 34. The sound output unit 66 is, for example, a speaker. The sound output unit 66 outputs, for example, sound related to operation instructions indicating the switching between automatic and manual driving.

[0057] The operation input unit 68 accepts input from the occupant. The operation input unit 68 is, for example, a touch panel. The operation input unit 68 is located on the display screen of the display unit 64. The operation input unit 68 is configured to display an image through the display unit 64. Therefore, the operation input unit 68 allows the occupant to visually confirm the image displayed on the display screen of the display unit 64. The operation input unit 68 accepts instructions input by the occupant touching a position corresponding to the image displayed on the display screen of the display unit 64 and sends them to the parking assist device 34. Furthermore, the operation input unit 68 is not limited to a touch panel; it can also be a hard switch such as a button.

[0058] The parking assist device 34 is a computer that includes a microcomputer such as an ECU (Electronic Control Unit) to assist the vehicle 10 in parking.

[0059] The parking assist device 34 includes a CPU 34a, a ROM (Read Only Memory) 34b, a RAM (Random Access Memory) 34c, a display control unit 34d, a sound control unit 34e, and an SSD (Solid State Drive) 34f. The CPU 34a, ROM 34b, and RAM 34c can also be integrated into the same package.

[0060] CPU 34a is an example of a hardware processor that reads a program stored in a non-volatile memory device such as ROM 34b and performs various calculations and controls based on the program. For example, CPU 34a performs parking assistance via the autonomous driving system of vehicle 10.

[0061] ROM 34b stores various programs and parameters required for program execution. RAM 34c temporarily stores various data used in the calculations of CPU 34a. The display control unit 34d mainly performs image processing of the image obtained by the imaging unit 14 and data transformation of the image displayed on the display unit 64 in the calculations of the parking assist device 34. The sound control unit 34e mainly performs sound processing of the sound output unit 66 in the calculations of the parking assist device 34. SSD 34f is a rewritable non-volatile storage device that retains data even when the power to the parking assist device 34 is disconnected.

[0062] The in-vehicle network 36 includes, for example, CAN (Controller Area Network) and LIN (Local Interconnect Network). The in-vehicle network 36 connects the acceleration system 24, braking system 22, steering system 26, transmission system 28, distance measuring unit 16, vehicle speed sensor 30, acceleration sensor 31, operation input unit 68 of monitoring device 32, and parking assistance device 34 to enable them to send and receive information.

[0063] Figure 3 This is a functional block diagram used to explain the functions of the parking assist device 34. For example... Figure 3 As shown, the parking assist device 34 includes an acquisition unit 71, a detection unit 72, an operation receiving unit 73, a parking assist unit 74, and a tilt angle storage unit 75. Furthermore, the parking assist unit 74 includes a target position calculation unit 74a, a path calculation unit 74b, a tilt angle calculation unit 74c, and a movement control unit 74d.

[0064] These acquisition unit 71, detection unit 72, operation receiving unit 73, and parking assist unit 74 are implemented by the CPU 34a reading and executing a program (parking program) stored in a storage device such as ROM 34b. Furthermore, some or all of the acquisition unit 71, detection unit 72, operation receiving unit 73, and parking assist unit 74 may also be constructed using hardware such as ASIC (Application Specific Integrated Circuit). Additionally, the tilt angle storage unit 75 is implemented, for example, by a storage unit such as RAM 34c.

[0065] The acquisition unit 71 acquires sensor values ​​from various sensors or acquires captured image data from the imaging unit 14.

[0066] The detection unit 72 detects obstacles and parking areas around the vehicle 10 based on the surrounding information (sensor values, captured image data, etc.) obtained by the acquisition unit 71.

[0067] The operation receiving unit 73 acquires (receives) a signal from the operation input unit 68 corresponding to the operation of the operation input unit 68.

[0068] The parking assistance unit 74 calculates the parking target position and movement path by controlling the automatic driving of the vehicle 10 through all or part of the control systems 22, 24, 26, and 28, and moves the vehicle 10 to the parking target position along the movement path. That is, the parking assistance unit 74 assists the parking of the vehicle 10.

[0069] The target position calculation unit 74a, for example, calculates (determines) the moving target position of the vehicle 10, which serves as a standard or target position for guiding the vehicle 10, using known methods, based on the detection results of the detection unit 72. In other words, it determines the parking target position. The parking target position can be either the end point or the middle point of the moving path. The parking target position can be set as a point, line, frame, area, etc.

[0070] The path calculation unit 74b calculates the movement path for moving the vehicle 10 from its current position to the parking target position using known methods or the like.

[0071] The tilt angle calculation unit 74c calculates, for example, information representing the tilt angle of the ground on which the vehicle 10 is traveling, i.e., first tilt angle information, based on the acceleration signal obtained from the acceleration sensor 31 according to a time series. In addition, the tilt angle calculation unit 74c performs filtering processing (e.g., LPF (Low-Pass Filter) processing, averaging filtering processing, etc.) on the waveform information represented by multiple first tilt angle information calculated according to the time series to remove high-frequency components above a predetermined threshold to calculate second tilt angle information.

[0072] Furthermore, the tilt angle calculation unit 74c determines whether there is a deviation between the first tilt angle information and the second tilt angle information based on a predetermined benchmark. This deviation can be determined, for example, by checking whether the difference between the instantaneous values ​​of the first and second tilt angle information is above a predetermined difference threshold, but it is not limited to this. If a deviation is determined to exist, the tilt angle calculation unit 74c resets (eliminates) the multiple first tilt angle information used in the filtering process, and uses the reset and calculated multiple first tilt angle information to perform filtering to calculate the second tilt angle information.

[0073] In addition, the tilt angle calculation unit 74c can also reset multiple first tilt angle information used in the filtering process if the time during which a deviation between the first tilt angle information and the second tilt angle information is determined to exist based on a predetermined benchmark continues for a predetermined time or more.

[0074] The motion control unit 74d performs motion control, in which it controls all or part of the systems 22, 24, 26, and 28 to control the driving force and braking force of the vehicle 10, so that the vehicle 10 moves along the movement path to the parking target position. Furthermore, when performing motion control, the motion control unit 74d adjusts the driving force and braking force based on the second tilt angle information. For example, if the second tilt angle information indicates an uphill slope, the motion control unit 74d increases the driving force based on the second tilt angle information. Similarly, if the second tilt angle information indicates a downhill slope, the motion control unit 74d increases the braking force based on the second tilt angle information.

[0075] In addition, if the tilt angle calculation unit 74c resets the multiple first tilt angle information used in the filtering process, the movement control unit 74d can also use the first tilt angle information instead of the second tilt angle information to perform movement control after the reset until the second tilt angle information is calculated by the tilt angle calculation unit 74c.

[0076] Next, use Figures 4-6 The changes in tilt angle information during parking assistance are explained. Figure 4 This is a diagram illustrating an example of road inclination during a parking assist implementation. Figure 5 This is a chart related to the tilt angle in the parking assist of the comparative example. Figure 6 This is a graph related to the tilt angle in the parking assist implementation.

[0077] like Figure 4 As shown, when the vehicle is moving to the right on the paper, the area between points P1 and P2 is uphill, and the area between points P2 and P3 is downhill. Here, the vehicle position at C1 is the starting point of the parking assist, and the vehicle position at C4 is the ending point of the parking assist (in other words, the target parking position).

[0078] When the vehicle position changes to C1, C2, C3, or C4, in the comparative example (prior art), the following is performed: Figure 5 The tilt angle is identified as shown. Data L1 is the tilt angle calculated based on the acceleration signal from the accelerometer. Data L1 includes high-frequency noise, so a filter is performed to remove this noise. Data L2 is the tilt angle after this filtering process. Additionally, data L3 is the true value of the tilt angle.

[0079] Comparing data L2 and data L3 reveals that when the road changes from uphill to downhill (near location P2), the filtered tilt angle (data L2) is delayed compared to the true tilt angle (data L3). Consequently, the vehicle travels at a higher speed than expected just before reaching the parking target position (C4), requiring emergency braking to stop at the target position. Therefore, there is room for improvement.

[0080] In the method of this embodiment, such as Figure 6 The tilt angle is identified as shown. Data L1, L2 and... Figure 5 The situation is the same. In the method of this embodiment, although the result is obtained up to location P4... Figure 5 The tilt angle is shown in data L2, but the tilt angle calculation unit 74c determines at location P4 that there is a deviation between data L2 and data L1. Therefore, the tilt angle calculation unit 74c resets (eliminates) the most recent data L1 used in the filtering process, and uses the reset data L1 to perform filtering to calculate the data L4.

[0081] Comparing data L4 and data L2, we can see that data L4 recovers from the bias and follows the true value (data L3) much earlier than data L2.

[0082] Next, refer to Figure 7 The parking assistance process performed by the parking assistance device 34 in the embodiment will be described. Figure 7 This is a flowchart of the parking assistance process performed by the parking assistance device 34 in the implementation method.

[0083] In step S1, if the operation receiving unit 73 receives parking assistance instructions from the occupant via the operation input unit 68, then in step S2, the target position calculation unit 74a calculates the parking target position based on the detection result of the detection unit 72.

[0084] Next, in step S3, the path calculation unit 74b calculates a movement path for moving the vehicle 10 from its current position to the parking target position.

[0085] Next, in step S4, the motion control unit 76c performs motion control to move the vehicle 10 along the motion path to the parking target position.

[0086] here, Figure 8 It means Figure 7 A detailed flowchart of step S4 is provided. In step S41, the tilt angle calculation unit 74c calculates information representing the tilt angle of the ground on which the vehicle 10 is traveling, i.e., the first tilt angle information, based on the acceleration signal obtained from the acceleration sensor 31 and according to the time series. Figure 6 Data L1).

[0087] Next, in step S42, the tilt angle calculation unit 74c performs filtering processing on the waveform information represented by multiple first tilt angle information calculated in step S41 according to the time series configuration, removing high-frequency components above a predetermined threshold, to calculate the second tilt angle information. Figure 6 Data L2).

[0088] Next, in step S43, the tilt angle calculation unit 74c determines whether there is a deviation between the first tilt angle information and the second tilt angle information based on a predetermined benchmark. If yes, it proceeds to step S44; otherwise, it proceeds to step S45.

[0089] In step S44, the tilt angle calculation unit 74 resets the multiple first tilt angle information used in the filtering process.

[0090] In step S45, the movement control unit 74d performs movement control to adjust the driving force and braking force of the vehicle 10 so that the vehicle 10 moves along the movement path to the parking target position. At this time, the driving force and braking force are adjusted based on the second tilt angle information. For example, if the second tilt angle information indicates an uphill slope, the movement control unit 74d increases the driving force based on the second tilt angle information. Conversely, if the second tilt angle information indicates a downhill slope, the movement control unit 74d increases the braking force based on the second tilt angle information.

[0091] In addition, if the tilt angle calculation unit 74c resets the multiple first tilt angle information used in the filtering process, the movement control unit 74d can also use the first tilt angle information instead of the second tilt angle information to perform movement control after the reset until the second tilt angle information is calculated by the tilt angle calculation unit 74c.

[0092] Next, in step S46, the motion control unit 74d determines whether the vehicle 10 has reached the parking target position. If yes, the process of step S4 ends; otherwise, it returns to step S41.

[0093] Thus, according to the parking assist device 34 of the first embodiment, when it is determined that there is a deviation between the first tilt angle information and the second tilt angle information, the multiple first tilt angle information used in the filtering process can be reset, so that the second tilt angle information calculated subsequently follows the true value earlier. In other words, the accuracy of recognizing the tilt angle of the ground during parking assistance can be improved.

[0094] Therefore, for example, even when the parking target location is on a slope that changes from uphill to downhill, it is possible to intentionally reduce the likelihood and extent to which the vehicle will become faster than expected before reaching the parking target location, and to suppress situations where emergency braking is required to stop at the parking target location.

[0095] In addition, for example, by performing the reset if the time at which the deviation is determined to exist continues for more than a specified period of time, erroneous resets can be prevented more reliably.

[0096] Alternatively, for example, by using the first tilt angle information instead of the second tilt angle information after the reset until the second tilt angle information is calculated, movement control can be performed continuously.

[0097] (Modified Example)

[0098] Next, a modified example of the parking assist device 34 will be described. When the tilt angle calculation unit 74c resets the multiple first tilt angle information used in the filtering process, the movement control unit 74d performs movement control immediately after the reset using the prescribed tilt angle information obtained based on the multiple first tilt angle information calculated before the reset.

[0099] If using Figure 6 To explain, even when data L2 deviates from data L3 (the true value) near locations P4 and P2, for example, in data L1, approximately the midpoint between the upper and lower peak values ​​becomes the true value. Therefore, immediately after the reset, the movement control unit 74d can use the midpoint between the upper and lower peak values ​​in data L1 as the specified tilt angle information for movement control, based on multiple first tilt angle information calculated before the reset.

[0100] Thus, according to the modified parking assist device 34, by using the prescribed tilt angle information (tilt angle information closer to the true value) obtained based on multiple first tilt angle information acquired before the reset immediately following the reset, more appropriate movement control can be performed.

[0101] Furthermore, the specified tilt angle information is not limited to the value between the upper peak and the lower peak in the data L1 described above. For example, other values ​​may be used, such as the value obtained by averaging the data L1 over a specified time period.

[0102] Furthermore, the program used to perform the aforementioned processing executed by the parking assist device 34 can also be provided as a computer program product, stored as an installable or executable file on a computer-readable storage medium such as a CD-ROM, CD-R, memory card, DVD (Digital Versatile Disk), or floppy disk (FD). Alternatively, the program can be stored on a computer connected to a network such as the Internet and provided by downloading it via the network. Additionally, the program can be provided or distributed via a network such as the Internet.

[0103] The embodiments of the present invention have been described above, but these embodiments are provided as examples and are not intended to limit the scope of the invention. This new embodiment can be implemented in various other ways, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. This embodiment and its variations are included within the scope and spirit of the invention, and are also included within the scope of the invention as described in the claims and its equivalents.

Claims

1. A parking assist device, comprising: The path calculation unit calculates the movement path for moving the vehicle from its current position to the target parking position. The tilt angle calculation unit calculates information representing the tilt angle of the ground on which the vehicle is traveling, i.e., first tilt angle information, based on a time series. It then performs filtering processing on the waveform information represented by the multiple first tilt angle information calculated based on the time series to remove high-frequency components above a predetermined threshold, and calculates second tilt angle information. If it is determined based on a predetermined benchmark that there is a deviation between the first tilt angle information and the second tilt angle information, it resets the multiple first tilt angle information used in the filtering process, and performs the filtering process on the multiple first tilt angle information calculated after the reset to calculate the second tilt angle information. as well as The movement control unit performs movement control by controlling the driving force and braking force of the vehicle to move the vehicle along the movement path to the parking target position. At this time, the driving force and braking force are adjusted according to the second tilt angle information.

2. The parking assist device according to claim 1, wherein, If the tilt angle calculation unit determines, based on the aforementioned standard, that there is a deviation between the first tilt angle information and the second tilt angle information for a period of time or longer, it resets the plurality of first tilt angle information used in the aforementioned filtering process.

3. The parking assist device according to claim 1, wherein, When the tilt angle calculation unit resets the multiple first tilt angle information used in the filtering process, After the reset, the motion control unit performs the motion control using the first tilt angle information instead of the second tilt angle information until the tilt angle calculation unit starts calculating the second tilt angle information.

4. The parking assist device according to claim 1, wherein, When the tilt angle calculation unit resets the multiple first tilt angle information used in the filtering process, Immediately after the reset, the motion control unit performs the motion control using predetermined tilt angle information obtained based on multiple first tilt angle information calculated by the tilt angle calculation unit prior to the reset.

5. A parking assistance method, comprising: The path calculation step calculates the movement path used to move the vehicle from its current position to the target parking position. The tilt angle calculation step involves calculating the tilt angle information, i.e., the first tilt angle information, representing the tilt angle of the ground on which the vehicle is traveling, based on a time series. Then, the waveform information represented by the multiple first tilt angle information calculated based on the time series is filtered to remove high-frequency components above a predetermined threshold to calculate the second tilt angle information. If, based on a predetermined benchmark, a deviation exists between the first tilt angle information and the second tilt angle information, the multiple first tilt angle information used in the filtering process is reset, and the multiple first tilt angle information calculated after the reset is used to perform the filtering process to calculate the second tilt angle information. as well as In the movement control step, the driving force and braking force of the vehicle are controlled to move the vehicle along the movement path to the parking target position. At this time, the driving force and braking force are adjusted according to the second tilt angle information.

6. A computer-readable storage medium storing a computer program for causing a computer to function as a component: The path calculation unit calculates the movement path for moving the vehicle from its current position to the target parking position. The tilt angle calculation unit calculates information representing the tilt angle of the ground on which the vehicle is traveling, i.e., first tilt angle information, based on a time series. It then performs filtering processing on the waveform information represented by the multiple first tilt angle information calculated based on the time series to remove high-frequency components above a predetermined threshold, and calculates second tilt angle information. If it is determined based on a predetermined benchmark that there is a deviation between the first tilt angle information and the second tilt angle information, it resets the multiple first tilt angle information used in the filtering processing, and performs the filtering processing on the multiple first tilt angle information calculated after the reset to calculate the second tilt angle information. as well as The movement control unit performs movement control by controlling the driving force and braking force of the vehicle to move the vehicle along the movement path to the parking target position. At this time, the driving force and braking force are adjusted according to the second tilt angle information.

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