Advancement direction display method and device for same

Abstract

When causing a display (4) to display the advancement direction of a vehicle (1), a processor (6) detects an operation state for a steering wheel (3) and, when the vehicle (1) is turning and a counter-steer operation has been performed, maintains the previous turning direction and causes the display (4) to display said turning direction as the advancement direction of the vehicle (1). As a result, the advancement direction of the vehicle as displayed at the display (4) does not deviate from the actual advancement direction of the vehicle (1) even when a counter-steer operation has been performed during turning.

Description

Traveling direction display method and apparatus thereof

[0001] The present invention relates to a traveling direction display method and an apparatus thereof.

[0002] In the following Patent Document 1, when a steering wheel is operated (steered) during turning of a vehicle, the turning radius of the vehicle is calculated according to the steering angle, and the traveling direction of the vehicle is displayed on a display according to the turning radius.

[0003] Japanese Unexamined Patent Publication No. 10-218007

[0004] In the traveling direction display device described in the above Patent Document 1, the turning direction, that is, the displayed traveling direction of the vehicle is determined according to the steering angle that also indicates the steering direction. Therefore, for example, when oversteer occurs during turning and the driver performs a counter-steering operation, the steering wheel is operated in the direction opposite to the previous direction, so the traveling direction of the vehicle displayed on the display is set to the reverse direction different from the previous turning direction, that is, toward the outer side of the turning direction. However, even when the counter-steering operation is performed, the actual vehicle remains in the same turning state as before, so a discrepancy arises between the traveling direction displayed on the display and the actual traveling direction. An object of the present invention is to provide a traveling direction display method and an apparatus thereof that prevent a deviation from occurring between the traveling direction of the vehicle displayed on the display and the actual traveling direction of the vehicle even when a counter-steering operation is performed during turning.

[0005] One aspect of the present invention is summarized as detecting the operation state of the steering wheel when the traveling direction of the vehicle is displayed on a display by an arithmetic processing unit, and when the vehicle is turning and a counter-steering operation is performed, maintaining the previous turning direction and displaying the turning direction on the display as the traveling direction of the vehicle.

[0006] According to one aspect of the present invention, when counter-steering is performed during a turn, the previous turning direction is maintained, and that turning direction is displayed on the display as the vehicle's direction of travel. Therefore, even if counter-steering is performed during a turn, there is no discrepancy between the vehicle's direction of travel displayed on the display and the actual vehicle's direction of travel. The object and advantages of the present invention are embodied and achieved using the elements and combinations thereof set forth in the claims. Both the above general description and the following detailed description are merely illustrative and explanatory and should be understood not to limit the present invention in the same way as the claims.

[0007] This is a schematic block diagram of a vehicle equipped with the directional display system of the embodiment. This is an explanatory diagram showing an example of the directional display shown on the display in Figure 1. This is a flowchart of the calculation process performed in the processor of the display controller in Figure 1. This is a timing chart explaining the operation of the calculation process in Figure 3. This is an explanatory diagram of the directional display content based on the calculation process in Figure 3. This is an explanatory diagram of the directional display content based on the calculation process in Figure 3. This is an explanatory diagram of the directional display content by a conventional directional display system. This is an explanatory diagram of the directional display content by a conventional directional display system.

[0008] Embodiments of the present invention will be described below with reference to the drawings. Note that each drawing is schematic and may differ from reality. Figure 1 shows a direction of travel display system that displays the direction of travel of the vehicle 1 on a display 4 provided on the instrument panel of the vehicle 1. This display 4 may display a large amount of information simultaneously, but here it will be described as displaying only the direction of travel of the vehicle 1. The vehicle 1 is equipped with two front wheels 2F and two rear wheels 2R, similar to a typical vehicle, and the front wheels 2F are steered by steering the steering wheel 3. Figure 2 shows an example of the display content of the direction of travel shown on the display 4. On this display 4, a schematic diagram in which a plan view of the vehicle is superimposed on a plan view of the roadway (lane markers) is displayed on the left half of the display 4, and an arrow indicating the direction of travel of the vehicle is displayed on the right half of the display 4. Figure 2a shows the state of the vehicle traveling in a straight line (straight-line travel state). Therefore, an arrow indicating straight travel is displayed on the left half of the display 4 at the front position of the straight road and vehicle plan view, and the right half shows the state of the vehicle traveling in a straight line with an upward-pointing arrow. Figure 2b shows the state of the vehicle traveling in a left-hand turn (left-hand turn travel state). Therefore, an arrow indicating left turn is displayed on the left half of the display 4 at the front position of the left-hand turn road and vehicle plan view, and the right half shows the state of the vehicle turning left with an upward-sloping arrow. Figure 2c shows the state of the vehicle traveling in a right-hand turn (right-hand turn travel state). Therefore, an arrow indicating right turn is displayed on the left half of the display 4 at the front position of the right-hand turn road and vehicle plan view, and the right half shows the state of the vehicle turning right with an upward-sloping arrow.

[0009] Returning to Figure 1, the content displayed on the display 4 is controlled by the display controller 5. This display controller 5 is an electronic control unit (ECU) that performs calculations to display the direction of travel of the vehicle 1 and outputs a display signal to the display 4. Therefore, this display controller 5 is equipped with a computer system that has advanced calculation capabilities. This computer system, like well-known computer systems, has a processor 6 that has advanced calculation functions. The processor 6 includes a ROM (Read Only Memory) where programs are stored, a CPU (Central Processing Unit) that executes the programs stored in the ROM, and a RAM (Random Access Memory) that functions as an accessible storage device. The storage device consists of a semiconductor storage device, a magnetic storage device, and an optical storage device. The storage device may further include registers, a cache memory, and a memory used as main memory. The calculations performed by the display controller 5 are realized, for example, by the CPU executing a computer program stored in the storage device within the processor 6 of the display controller 5.

[0010] To enable the processor 6 in the display controller 5 to function, the vehicle 1 is equipped with a steering angle sensor 7 that detects the amount of steering wheel 3 operated, i.e., the steering angle. This steering angle sensor 7 outputs a detection signal to the processor 6 consisting of a combination of the magnitude (numerical value) of the steering angle, which is the amount of steering wheel 3 operated, and a positive or negative sign indicating the direction of steering. In this embodiment, the steering angle sensor 7 detects and outputs a positive steering angle when the steering wheel 3 is turned to the left, and a negative steering angle when it is turned to the right. The vehicle 1 is also equipped with a lateral acceleration sensor 8 that detects the lateral acceleration acting on the vehicle 1, and a yaw rate sensor 9 that detects the yaw rate acting on the vehicle 1. The lateral acceleration sensor 8 outputs a detection signal to the processor 6 consisting of a combination of the magnitude (numerical value) of the lateral acceleration and a positive or negative sign indicating the direction of the lateral acceleration. In this embodiment, the lateral acceleration sensor 8 detects and outputs a positive lateral acceleration when the direction of the lateral acceleration acting on the vehicle 1 is to the left, and a negative lateral acceleration when it is to the right. The yaw rate sensor 9 outputs a detection signal to the processor 6 consisting of a combination of the magnitude (numerical value) of the yaw rate and a positive or negative sign indicating the direction of the yaw rate. In this embodiment, the yaw rate sensor 9 detects and outputs a yaw rate that is positive when the yawing motion around the axis of rotation is counterclockwise and negative when it is clockwise, in a plan view of the vehicle. Note that the yaw rate detected by the yaw rate sensor 9 is not used to control the content displayed on the display 4. The vehicle 1 is also equipped with a driving speed sensor 10 that detects the vehicle's longitudinal speed, i.e., its driving speed. In this embodiment, the driving speed sensor 10 detects and outputs a positive driving speed when the vehicle 1 is moving forward.

[0011] Next, the calculation process performed by the processor 6 in the display controller 5 will be explained using the flowchart of the calculation process in Figure 3. This calculation process is performed, for example, by a predetermined timer interrupt process. First, in step S1, the steering angle detected by the steering angle sensor 7, the driving speed detected by the driving speed sensor 10, and the lateral acceleration detected by the lateral acceleration sensor 8 are read. Hereafter, the detected lateral acceleration will be referred to as the actual lateral acceleration, assuming it is the lateral acceleration actually occurring in the vehicle 1. Next, the process moves to step S2, where the lateral acceleration occurring in the vehicle 1 is calculated from the steering angle and driving speed read in step S1. Here, the calculated lateral acceleration will be referred to as the estimated lateral acceleration to differentiate it from the actual lateral acceleration. The lateral acceleration occurring in the vehicle 1 (estimated lateral acceleration) is expressed as the product of the driving speed and the turning angular velocity, and the turning angular velocity is correlated with the steering angle (steering speed). Therefore, for example, the correlation between the steering angle and the turning angular velocity can be mapped, and the estimated lateral acceleration can be obtained from the product of the turning angular velocity corresponding to this steering angle and the driving speed. Next, the process moves to step S3 to determine whether the estimated lateral acceleration is below a predetermined negative threshold (right). If the estimated lateral acceleration is below the threshold (right), the process moves to step S4; otherwise, it moves to step S5. The threshold (right) is a predetermined negative value with a relatively small absolute value that allows the system to determine, based on the estimated lateral acceleration obtained from the travel speed and steering angle, that a rightward lateral acceleration is acting on vehicle 1. In step S4, the temporary displayed direction of travel is set to "right" before proceeding to step S9.

[0012] In step S5, it is determined whether the estimated lateral acceleration is greater than or equal to a predetermined positive threshold (left). If the estimated lateral acceleration is greater than or equal to the threshold (left), the process proceeds to step S6; otherwise, it proceeds to step S7. The threshold (left) is a predetermined positive value with a relatively small absolute value that allows the system to determine, based on the estimated lateral acceleration obtained from the travel speed and steering angle, that a leftward lateral acceleration is acting on vehicle 1. In step S6, the temporary displayed direction of travel is set to "left" before proceeding to step S9. In step S7, it is determined whether a predetermined time has elapsed while the flow from step S5 to step S7 has been repeated. If the predetermined time has elapsed while the flow to step S7 has been repeated, the process proceeds to step S8; otherwise, it proceeds to step S11. In step S8, the temporary displayed direction of travel is set to "straight ahead" before proceeding to step S9. In step S9, it is determined whether the sign of the estimated lateral acceleration matches the sign of the actual lateral acceleration. If the signs of the estimated lateral acceleration and the actual lateral acceleration match, the process proceeds to step S10; otherwise, it proceeds to step S11. Note that if the actual lateral acceleration detected by the lateral acceleration sensor 8 is too small to determine its sign, the signs of the estimated lateral acceleration and the actual lateral acceleration are considered to match. In step S10, the temporary display direction of travel is set to the display direction of travel before proceeding to step S12. In step S11, the previously displayed direction of travel is set to the display direction of travel before proceeding to step S12. In step S12, the display processing for the direction of travel set to the display direction of travel is performed according to individual calculation processes (not shown), and then the process returns.

[0013] According to this calculation process, if the estimated lateral acceleration is below a negative threshold (right), the temporary displayed direction of travel is set to "right," and if the estimated lateral acceleration is above a positive threshold (left), the temporary displayed direction of travel is set to "left." Furthermore, if the estimated lateral acceleration is above the threshold (right) and below the positive threshold (left), and this condition persists for a predetermined time, the temporary displayed direction of travel is set to "straight." If the sign of the estimated lateral acceleration matches the sign of the actual lateral acceleration, the temporary displayed direction of travel is set to the displayed direction of travel; otherwise, the previously displayed direction of travel is set to the displayed direction of travel, and the set displayed direction of travel is displayed on the display 4. Therefore, even when the vehicle is turning on a road surface with a low coefficient of friction, such as an icy or snowy road, and the absolute value of the actual lateral acceleration detected by the lateral acceleration sensor 8 is small, making it difficult to determine the turning direction or state of the vehicle 1, the absolute value of the estimated lateral acceleration calculated from the steering angle and travel speed is of a certain magnitude, making it possible to identify the turning motion of the vehicle 1 and its direction. Normally, the estimated lateral acceleration and the actual lateral acceleration are in the same direction, meaning the signs of the estimated lateral acceleration and the actual lateral acceleration are the same. Therefore, the turning direction, which is defined by the sign of the estimated lateral acceleration and set as the provisional displayed direction of travel, should be displayed as the displayed direction of travel.

[0014] On the other hand, if the vehicle experiences oversteer during a turn and the driver performs counter-steer, for example, even though vehicle 1 is actually turning left, the steering direction of the steering wheel 3 due to the counter-steer operation becomes a right turn. As a result, the estimated lateral acceleration is negative and the actual lateral acceleration is positive, and the signs do not match. Therefore, in such a situation, the previously displayed direction of travel, i.e., the left turn direction, is set as the displayed direction of travel, and while counter-steer is being performed, the left turn direction is displayed on the display 4. This ensures that the actual direction of travel of vehicle 1 matches the displayed direction of travel of the vehicle, creating a sense of familiarity. Furthermore, if the oversteer condition is resolved while the vehicle is still in the same left turn state, and the driver turns the steering wheel 3 to the left in accordance with the turning direction, the estimated lateral acceleration corresponding to the steering angle becomes positive, and the actual lateral acceleration also becomes positive, the same as in a normal turn. Therefore, the left turn direction, which is set as the temporary displayed direction of travel, is set as the displayed direction of travel and is displayed on the display 4. As a result, the actual direction of travel of vehicle 1 matches the displayed direction of travel of the vehicle, creating a sense of familiarity. Furthermore, if the vehicle transitions from any turning state to a straight-ahead state, a predetermined time (ΔT) will be set after the transition. Ｈ For 2 seconds, the previously displayed direction of travel, i.e., the turning direction, is displayed on the display 4. This prevents flickering of the display content on the display 4, for example, when fine steering corrections are needed during the transition from a turning state to a straight-ahead state, thus avoiding inconvenience to the crew.

[0015] Figure 4 is a timing chart of the steering angle, yaw rate, estimated lateral acceleration, actual lateral acceleration, and displayed direction of travel calculated in Figure 3 when a vehicle is traveling on a certain road and transitions from straight-ahead driving to a right-hand turn, then from straight-ahead driving to a left-hand turn, and then from straight-ahead driving to a left-hand turn again. In the first right-hand turn and the subsequent left-hand turn, the steering angle, the estimated lateral acceleration calculated from the steering angle, and the actual lateral acceleration detected by the lateral acceleration sensor 8 are almost identical. For example, in the first right-hand turn, the right-hand turn direction is displayed on the display 4 as the vehicle's direction of travel when the estimated lateral acceleration falls below a negative threshold (right), and in the subsequent left-hand turn, the left-hand turn direction is displayed on the display 4 as the vehicle's direction of travel when the estimated lateral acceleration rises above a positive threshold (left). Therefore, in both cases, the actual direction of travel of the vehicle 1 and the displayed direction of travel of the vehicle match, resulting in a seamless display. Furthermore, during the initial right turn, a predetermined time ΔT is observed from the time when the estimated lateral acceleration exceeds a negative threshold (right). Ｈ During this time, the right turn direction will continue to be displayed on display 4, and in the next left turn, a predetermined time ΔT will be set from the time when the estimated lateral acceleration falls below the positive threshold (left). Ｈ During this time, the left turn direction is continuously displayed on display 4. During this time, the yaw rate detected by the yaw rate sensor 9 showed a change over time equivalent to that of the steering angle. On the other hand, during the second right turn, the yaw rate (absolute value) overshot midway through the right turn, resulting in an oversteer condition. In response, the driver performed a counter-steer operation by turning the steering wheel 3 to the left, causing the estimated lateral acceleration to shift significantly from the right to the left. Meanwhile, the actual lateral acceleration detected by the lateral acceleration sensor 8 remained to the right both during and after the counter-steer operation. Therefore, the estimated lateral acceleration shifted from a negative value to a positive value, and at the timing when the actual lateral acceleration remained negative, the previously displayed direction of travel, i.e., the right direction, was set as the displayed direction of travel, and the right turn direction continued to be displayed on display 4. Consequently, regardless of the steering direction of the steering wheel 3, the actual direction of travel of the vehicle 1 and the displayed direction of travel of the vehicle coincide, resulting in no sense of incongruity. Furthermore, when transitioning from right-turning to straight-ahead driving, a predetermined time ΔT is set from the time when the estimated lateral acceleration falls below the positive threshold (left).Ｈ Throughout this process, the right turn direction continues to be displayed on display 4, ensuring that the displayed direction of travel matches the actual direction of travel of vehicle 1, resulting in a seamless and natural appearance.

[0016] Figure 5 shows the content displayed on the display 4 as a result of the calculation process in Figure 3, in chronological order as the vehicle turns left. In this example, during the left turn, the vehicle 1 does not experience oversteer or understeer, and turns left in a neutral steering state along the driving trajectory selected by the driver. In the lower right figure of the same diagram, which corresponds to the start of the left turn, the steering wheel 3 is turned slightly to the left, causing the front wheels 2F to turn to the left. However, since the estimated lateral acceleration is below the threshold (left), the temporary display direction of travel is set to "straight ahead," and this is set as the display direction of travel, resulting in the straight-ahead driving state shown in Figure 2a being displayed on the display 4. In the middle figure of the same diagram, which corresponds to the middle of the left turn, the steering wheel 3 is turned to the left, causing the front wheels 2F to turn to the left. Since the estimated lateral acceleration is above the threshold (left), the temporary display direction of travel is set to "left," and this is set as the display direction of travel, resulting in the left-turn driving state shown in Figure 2b being displayed on the display 4. In the upper left diagram of the same figure, which corresponds to the exit of a left turn, the steering wheel 3 is turned back, but the steering is still in a left-turn state, so the front wheels 2F are turned to the left, and the estimated lateral acceleration is still above the threshold (left), so the temporary displayed direction of travel is set to "left," and this remains the displayed direction of travel, and the left-turn driving state shown in Figure 2b continues to be displayed on the display 4. Subsequently, when the steering wheel 3 is turned back further and the estimated lateral acceleration converges, the temporary displayed direction of travel is set to "straight," and from that setting for a predetermined time ΔT Ｈ Once the specified time has elapsed, the straight-ahead driving state shown in Figure 2a will be displayed on the display 4.

[0017] Figure 6 shows the display content shown on the display 4 as a result of the calculation process in Figure 3, in chronological order as the vehicle turns left. In this example, after the start of the left turn, the vehicle 1 enters an oversteer state, to which the driver countersteers the steering wheel 3. Subsequently, the oversteer state subsides, and the vehicle ends the left turn in a neutral steer state. In the lower right diagram of the same figure, which corresponds to the entrance of the left turn, the steering wheel 3 is turned slightly to the left, causing the front wheels 2F to turn to the left, similar to Figure 5. However, since the estimated lateral acceleration is below the threshold (left), the temporary display direction of travel is set to "straight ahead," and this is set as the display direction of travel, so the straight-ahead driving state shown in Figure 2a is displayed on the display 4. After that, the steering wheel 3 is turned to the left until the driver countersteers, and during that time the vehicle 1 turns left in a neutral steer state, and the left turn state shown in Figure 2b is displayed on the display 4. In the middle diagram of the same figure, which corresponds to the middle stage of left-turn driving, the steering wheel 3 is counter-steered, resulting in a rightward steering input and the front wheel 2F turning to the right. As a result, an estimated rightward lateral acceleration below the threshold (right) is calculated, and the temporary displayed direction of travel is set to "right". Meanwhile, at this time, a leftward actual lateral acceleration is acting on the vehicle 1, and as a result, the displayed direction of travel is set to "left", which was the previously displayed direction of travel. Consequently, the left-turn driving state shown in Figure 2b continues to be displayed on the display 4. In the upper left diagram of the same figure, which corresponds to the exit of left-turn driving, the steering wheel 3 is turned back to a leftward steering input, and the front wheel 2F turns to the left. As the estimated lateral acceleration is above the threshold (left), the temporary displayed direction of travel is set to "left", and this remains the displayed direction of travel, and the left-turn driving state shown in Figure 2b continues to be displayed on the display 4. After that, when the steering wheel 3 is turned back and the estimated lateral acceleration converges, the temporary displayed direction of travel is set to "straight ahead", and from that setting for a predetermined time ΔT Ｈ Once the specified time has elapsed, the straight-ahead driving state shown in Figure 2a will be displayed on the display 4.

[0018] Figure 7 shows the content displayed on the display 4 by a conventional direction of travel display system in chronological order during left-turn driving. This system displays the direction of travel of the vehicle 1 according to the steering direction of the steering wheel 3 when the actual lateral acceleration (absolute value) detected by the lateral acceleration sensor 8 is above a threshold. The content displayed on the display 4 is the same as that of the embodiment shown in Figure 2. In this example, as in Figure 6, an oversteer state occurs after the start of left-turn driving, to which the driver counter-steers the steering wheel 3, and then the oversteer state subsides and the left-turn driving ends in a neutral steer state. In the lower right diagram of the same figure, which corresponds to the entrance of left-turn driving, the steering wheel 3 is turned slightly to the left and the front wheels 2F turn to the left, but since the actual lateral acceleration (absolute value) is below the threshold, the displayed direction of travel is set to "straight ahead", and as a result the straight-ahead driving state shown in Figure 2a is displayed on the display 4. Subsequently, until the driver performs a counter-steer operation, the steering wheel 3 is steered to the left, and during that time, the vehicle 1 travels in a left turn in a neutral steer state, and the display 4 shows the left turn travel state as shown in Figure 2b. In the middle diagram of the same figure, which corresponds to the middle of the left turn travel, the steering wheel 3 is steered to the right by the counter-steer operation, so the displayed direction of travel is set to "right," and as a result, the right turn travel state shown in Figure 2c is displayed on the display 4. That is, at this point, even though the vehicle 1 is traveling in a left turn, the display 4 shows the right turn travel state, and the actual direction of travel of the vehicle 1 and the displayed direction of travel of the vehicle are different. In the upper left diagram of the same figure, which corresponds to the exit of the left turn travel, the steering wheel 3 has been turned back to the left steer state, so the displayed direction of travel is set to "left," and as a result, the left turn travel state shown in Figure 2b is displayed on the display 4. Subsequently, when the steering wheel 3 is turned back and the actual lateral acceleration converges, the displayed direction of travel is set to "straight," and as a result, the straight-ahead travel state shown in Figure 2a is displayed on the display 4.

[0019] Figure 8 shows the display content shown on the display 4 by the conventional direction of travel display system in chronological order during left-turn driving. When the actual lateral acceleration (absolute value) detected by the lateral acceleration sensor 8 is above a threshold, the direction of travel of the vehicle 1 corresponding to the steering direction of the steering wheel 3 is displayed. The display content of the display 4 is the same as that of the embodiment shown in Figure 2. In this example, as in the case of Figure 5, the vehicle was able to continue driving in a neutral steer state from the start to the end of the left-turn driving, but the coefficient of friction of the road surface was small, and the actual lateral acceleration generated in the vehicle 1 remained small until the left-turn driving was completed. In the lower right diagram of the same figure, which corresponds to the entrance of the left-turn driving, the steering wheel 3 is turned slightly to the left, causing the front wheels 2F to turn to the left, but since the actual lateral acceleration (absolute value) is below the threshold, the displayed direction of travel is set to "straight ahead", and as a result, the straight-ahead driving state shown in Figure 2a is displayed on the display 4. In the middle diagram of the same figure, which corresponds to the middle stage of left-turn driving, the steering wheel 3 is turned to the left, causing the front wheels 2F to turn to the left and the vehicle to turn left. However, the actual lateral acceleration (absolute value) does not exceed the threshold, and as a result, the straight-ahead driving state shown in Figure 2a continues to be displayed on the display 4. In the upper left diagram of the same figure, which corresponds to the exit of left-turn driving, although the steering wheel 3 has been turned back, the steering is still in a left-turn state, causing the front wheels 2F to turn to the left and the vehicle 1 to turn left. However, the actual lateral acceleration (absolute value) does not exceed the threshold, and the straight-ahead driving state shown in Figure 2a continues to be displayed on the display 4. In other words, even in such cases, with conventional direction of travel display systems, the actual direction of travel of the vehicle 1 and the direction of travel of the displayed vehicle are different.

[0020] The above describes the directional display system of the embodiment, but the present invention is not limited to the configuration described in the above embodiment, and various modifications are possible within the scope of the gist of the present invention. For example, in the above embodiment, if the direction (sign) of the estimated lateral acceleration calculated from the steering angle and driving speed does not match the direction (sign) of the actual lateral acceleration detected by the lateral acceleration sensor 8, it is assumed that a counter-steer operation was performed during turning, and the previous turning direction of the vehicle 1 is maintained and displayed on the display 4. However, if it is possible to determine that a counter-steer operation was performed during the same turning, that determination method may be used. An example of such a determination method is when the steering wheel 3 is steered in the opposite direction to the direction of curvature, which is the driving path information for the current turning.

[0021] In this embodiment, when the processor 6 displays the direction of travel of the vehicle 1 on the display 4, it detects the operating state of the steering wheel 3. If the vehicle 1 turns and counter-steer is performed, it maintains the previous turning direction and displays that turning direction as the direction of travel of the vehicle 1 on the display 4. This prevents a discrepancy between the direction of travel of the vehicle displayed on the display 4 and the actual direction of travel of the vehicle 1, even if counter-steer is performed during a turn. Furthermore, the actual lateral acceleration of the vehicle 1 is detected, and an estimated lateral acceleration of the vehicle 1 is calculated based on the steering angle of the steering wheel 3 and the vehicle's travel speed. If the calculated estimated lateral acceleration and the detected actual lateral acceleration direction match, the turning direction aligned with the calculated estimated lateral acceleration direction is set as the direction of travel of the vehicle. If they do not match, it is assumed that counter-steer has been performed, and the turning direction immediately before the discrepancy occurred is set as the direction of travel of the vehicle. This set direction of travel of the vehicle is then displayed on the display 4. This makes it possible to reliably determine whether counter-steer has been performed during the same turn, and ensures that the displayed direction of travel of the vehicle matches the actual direction of travel of the vehicle 1.

[0022] 1...Vehicle, 2F...Front wheels, 2R...Rear wheels, 3...Steering wheel, 4...Display, 5...Display controller, 6...Processor, 7...Steering angle sensor, 8...Lateral acceleration sensor, 9...Yaw rate sensor, 10...Driving speed sensor

Claims

1. A method for displaying the direction of travel of a vehicle on a display using a processing unit, wherein the processing unit detects the operation state of the steering wheel, and when the vehicle turns and counter-steer operation is performed, it maintains the turning direction immediately before the counter-steer operation is performed and displays that turning direction as the direction of travel of the vehicle on the display.

2. The method for displaying the direction of travel according to claim 1, characterized in that the processing unit comprises: a step of detecting the lateral acceleration of the vehicle; a step of calculating the lateral acceleration of the vehicle based on the steering angle of the steering wheel and the travel speed of the vehicle; a step of setting the turning direction to match the direction of the calculated lateral acceleration as the direction of travel of the vehicle if the direction of the calculated lateral acceleration and the direction of the detected lateral acceleration coincide, and if they do not coincide, a step of setting the turning direction immediately before the state of non-match as the direction of travel of the vehicle, assuming that the counter-steer operation has been performed; and a step of displaying the set direction of travel of the vehicle on a display.

3. A direction of travel display device that displays the direction of travel of a vehicle on a display using a processing unit, wherein the processing unit detects the operation state of the steering wheel, and when the vehicle turns and counter-steer operation is performed, maintains the turning direction immediately before the counter-steer operation is performed and displays that turning direction as the direction of travel of the vehicle on the display.

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