Display method and display system

Abstract

A controller (50) displays information on a display (20) which is fixed to a center part of a steering wheel (1) that steers a steered wheel of a vehicle. The controller (50) determines whether or not a driving assist function for assisting driving by a driver is operating. Upon determining that the driving assist function is operating, the controller (50) displays the information in a state such that the information does not rotate along with the rotation angle of the steering wheel (1).

Description

Display method and display system

[0001] The present invention relates to a display method and a display system.

[0002] Patent Literature 1 discloses a vehicle control device that can determine whether a driver can manually drive a vehicle while the vehicle is in automatic driving mode. The vehicle control device includes a liquid crystal monitor and a control unit. If the driver's grip position of the grip part does not change after a predetermined time has elapsed, a display provided on the steering wheel instructs the driver to make a contact action with the steering wheel within a specified time.

[0003] Japanese Patent Application Laid-Open No. 2020-040587

[0004] However, when the steering wheel rotates, the display attached to the steering wheel also rotates, which can make it difficult to see the information displayed on the display depending on the vehicle's condition.

[0005] An object of the present invention is to provide a display method and a display system that can display information in a form that is easy for the driver to see.

[0006] A display method according to one aspect of the present invention displays information on a display fixed to a center portion of a steering wheel that steers the wheels of a vehicle. In this display method, when a driving assistance function that assists a driver in driving is activated, the information is displayed in a state that does not rotate with the rotation angle of the steering wheel.

[0007] According to one aspect of the present invention, information can be displayed in a format that is easy for the driver to see.

[0008] FIG. 1 is a diagram schematically showing the configuration of a display system according to a first embodiment. FIG. 2 is a diagram illustrating an example of information displayed on a display. FIG. 3 is a flowchart showing a display method according to the first embodiment. FIG. 4 is a diagram showing information displayed in fixed display mode. FIG. 5 is a diagram showing information displayed in fixed display mode. FIG. 6 is a diagram showing information displayed in linked display mode. FIG. 7 is a diagram showing information displayed in linked display mode. FIG. 8 is a diagram illustrating the state of a driver's hands gripping the steering wheel. FIG. 9 is a diagram illustrating learning of a dead zone area. FIG. 10 is a diagram showing switching from the linked display mode to the fixed display mode. FIG. 11 is a diagram showing switching from the linked display mode to the fixed display mode. FIG. 12 is a diagram showing switching from the linked display mode to the fixed display mode. FIG. 13 is a diagram showing a display mode related to a parking assistance function. FIG. 14 is a diagram showing a display mode related to a parking assistance function. FIG. 15 is a flowchart showing a display method according to a second embodiment.

[0009] First Embodiment A steering wheel 1 mounted on a vehicle will be described with reference to Fig. 1. The steering wheel 1 is an operator for steering the steered wheels, and is held by the driver.

[0010] The steering wheel 1 is provided in the driver's seat of the vehicle and is positioned opposite the seat on which the driver sits. The steering wheel 1 is connected to a steering shaft (not shown) and is configured to be rotatable around a rotation axis 1a (steering shaft). When the driver turns the steering wheel 1, the driver's operating force is transmitted to the steered wheels via the steering mechanism. The steering mechanism may be of a type in which the steering wheel 1 is mechanically connected to a drive mechanism that drives the steered wheels, or of a steer-by-wire type in which the drive mechanism and the steering wheel 1 are mechanically separated.

[0011] The steering wheel 1 includes a wheel body 2, a boss portion 3, and a display 20.

[0012] The wheel body 2 is an annular member that is gripped by the driver. The wheel body 2 is arranged concentrically around the rotation axis 1a. The boss portion 3 is connected to the steering shaft. An airbag module is attached to the boss portion 3. The boss portion 3 also functions as a horn switch that the driver presses to sound the horn.

[0013] The display 20 is a display device that displays information necessary for the driver. The display 20 has an annular shape and is arranged concentrically around the rotation axis 1a. The display 20 is arranged in a range inside the steering wheel 1 and outside the boss portion 3. The display 20 is integrated with the wheel body 2 and the boss portion 3, and the wheel body 2, display 20, and boss portion 3 rotate together. In other words, the display 20 is fixed to the center of the steering wheel 1.

[0014] The display 20 is a transparent display that transmits external light while displaying information. An instrument panel is provided behind the steering wheel 1 as seen from the driver, and an instrument unit 100 is provided on the instrument panel. The instrument unit 100 includes instruments such as a speedometer, a tachometer, and a fuel gauge, as well as various warning lights. The driver can view the instrument unit 100 behind the steering wheel 1 through the transparent display 20. Note that the instrument unit 100 is depicted in a simplified form in FIG. 1 .

[0015] The display 20 is a touch panel display equipped with a touch panel through which a user inputs operation instructions. The touch panel detects an operation position on the display 20. The touch panel is, for example, of a capacitance type, but is not limited to this and may be of another type such as a resistive film type.

[0016] The vehicle according to this embodiment has a driving assistance function. The driving assistance function is a function in which a higher-level system (hereinafter referred to as the "assistance system") automatically executes one or more vehicle controls from among a plurality of vehicle controls, such as steering control, braking force control, driving force control, and shift control, thereby assisting the driver in driving operations. The driving assistance function may also be referred to as an automated driving function depending on the level of assistance. The driving assistance function according to this embodiment is a driving assistance function that assists the vehicle in staying within the lane of the road. When the driving assistance function is activated and steering control is performed by the assistance system, the driver can take his or her hands off the steering wheel 1. Furthermore, when steering control is performed by the assistance system, the steering wheel 1 also rotates in accordance with the rotation angle of the steered wheels, even if the driver does not operate the steering wheel 1.

[0017] The display system 10 according to this embodiment is composed of the display 20 described above and a controller 50. The controller 50 is composed of a computer having a hardware processor such as a CPU (Central Processing Unit), memory, and various interfaces. The CPU reads various computer programs stored in the memory and executes various instructions contained in the programs. By executing the programs, the CPU functions as various information processing circuits that execute the display method described below. The controller 50 realizes the functions of each information processing circuit using software, but it is also possible to realize those functions using dedicated hardware.

[0018] Various types of information are input to the controller 50. The steering grip signal Ss is a signal indicating the position of the wheel body 2 gripped by the driver. The steering grip signal Ss not only indicates the position when the driver grips the wheel body 2, but also indicates that the driver is gripping the wheel body 2. The steering grip signal Ss is output from a sensor such as a pressure sensor that detects the pressure acting on the wheel body 2 or a capacitance sensor that detects contact with the wheel body 2. The touch signal St is a signal indicating the touch position on the display 20. The touch signal St is output from the touch panel of the display 20. The steering angle signal Sθ is a signal indicating the steering angle of the steering wheel 1. The steering angle signal Sθ is output from a sensor that detects the rotation angle of the steering shaft. The driving assistance signal Sp is a signal that indicates whether a driving assistance function is operating and, if so, the type of driving assistance function. The driving assistance signal Sp is output from the assistance system.

[0019] In this embodiment, the controller 50 displays information on the display 20. The information displayed on the display 20 will be described with reference to FIG. 2. In FIG. 2, a reference line 2a shown by a dashed line on the wheel body 2 indicates a reference position on the wheel body 2. The reference line 2a is located directly above the steering wheel 1 when it is in the neutral position (the position shown in FIG. 2). Similarly, a reference line 3a shown by a dashed line on the boss portion 3 indicates a reference position on the boss portion 3. The reference line 3a extends in the up-down direction when the steering wheel 1 is in the neutral position. That is, FIG. 2 shows how information is displayed when the steering wheel 1 is in the neutral position.

[0020] The controller 50 displays the operation information Ic and the notification information Ii on the display 20 .

[0021] The operation information Ic includes one or more pieces of information for the driver to give an operation instruction. In the example shown in Fig. 2, the operation information Ic includes first operation information Ica, second operation information Icb, third operation information Icc, fourth operation information Icd, fifth operation information Ice, and sixth operation information Icf. Each of the operation information Ica, Icb, Icc, Icd, Ice, and Icf includes a symbol, character, or icon indicating each operation.

[0022] The first operation information Ica is information for operating the volume of the speaker installed in the vehicle. The second operation information Icb is information for performing an operation to return to the previous screen. The third operation information Icc is information for performing an operation to answer an incoming call and an operation to end a call. The fourth operation information Icd is information for performing an operation to set the set vehicle speed in the driving assistance function, or, after disabling the constant speed control function, to reset the set vehicle speed to the speed before disabling. The fifth operation information Ice is information for turning the driving assistance function on and off. The sixth operation information Icf is information for operating the turn signal. The sixth operation information Icf is displayed on the left and right sides of the rotation axis 1a of the steering wheel 1.

[0023] The notification information Ii is information for notifying the driver of various information. In the example shown in Fig. 2, the notification information Ii is exemplified by information for notifying the driver of information related to the driving support function. Specifically, the notification information Ii includes an icon indicating that the driver can release his / her hands from the steering wheel 1, an icon indicating whether a preceding vehicle has been detected, and text indicating the set speed for the driving support function.

[0024] The operation information Ic displayed on the display 20 is not limited to the above information, but may include information for operating various devices mounted on the vehicle. The notification information Ii is not limited to the above information, but may include other information related to the driving assistance function. The notification information Ii may also include information notifying information about the vehicle other than the driving assistance function. The content of the operation information Ic and the notification information Ii is dynamically changed depending on the state of the vehicle and the driving situation.

[0025] 3, a display method according to this embodiment, specifically, a method for displaying information on the display 20, will be described. The flowchart shown in FIG.

[0026] In step S10, the controller 50 refers to the driving assistance signal Sp and determines whether the driving assistance function is operating. If it is determined that the driving assistance function is operating (step S10: YES), the controller 50 performs the process of step S11. If it is determined that the driving assistance function is not operating (step S10: NO), the controller 50 performs the process of step S12.

[0027] In step S11, the controller 50 selects the fixed display mode. The fixed display mode is one of the display modes for displaying information on the display 20. As shown in FIGS. 4 and 5 , the fixed display mode is a display mode in which information is displayed in a fixed coordinate system X1Y1, in which the coordinate system is fixed regardless of the rotation angle of the steering wheel 1 (i.e., the display 20). A fixed coordinate system means that the coordinate system does not move regardless of the rotation of the steering wheel 1, and is synonymous with being fixed with respect to the vehicle body. The fixed coordinate system X1Y1 is defined by an X1 axis and a Y1 axis that are orthogonal to each other on a plane including the display 20. The origin of the fixed coordinate system X1Y1 coincides with the rotation axis 1a of the steering wheel 1.

[0028] As shown in Figure 4, when the steering wheel 1 is in the neutral position, the reference line 2a of the wheel body 2 and the reference line 3a of the boss portion 3 coincide with the Y1 axis. When the fixed display mode is selected, the controller 50 displays operation information Ic at a predetermined coordinate position according to the fixed coordinate system X1Y1. When the fixed display mode is selected, the driving assistance function is activated, so in the examples shown in Figures 4 and 5, notification information Ii related to the driving assistance function is also displayed on the display 20. Like the operation information Ic, the controller 50 displays the notification information Ii at a predetermined coordinate position according to the fixed coordinate system X1Y1.

[0029] The fixed coordinate system X1Y1 is fixed regardless of the rotation angle of the steering wheel 1. As shown in FIG. 5 , even if the steering wheel 1 is rotated from the neutral position due to steering of the steered wheels by the driving assistance function, the controller 50 maintains the fixed coordinate system X1Y1 in an unrotated state (immobile state) and displays the operation information Ic and the notification information Ii in this fixed coordinate system X1Y1. Therefore, regardless of the rotation angle of the steering wheel 1, the controller 50 displays the operation information Ic and the notification information Ii in the display state (position and orientation) that they have when the steering wheel 1 is in the neutral position. Therefore, if the same type of operation information Ic and notification information Ii are continuously displayed, the positions and orientations of the operation information Ic and the notification information Ii do not change even if the rotation angle of the steering wheel 1 changes.

[0030] As described above, in the fixed display mode, the operation information Ic and the notification information Ii are displayed in a state that does not rotate according to the rotation angle of the steering wheel 1. When the driving assistance function is activated, the driver can remove his / her hands 200 from the steering wheel 1. Regardless of the rotation angle of the steering wheel 1, the display state of the operation information Ic and the notification information Ii as seen by the driver remains the same, so the driver can easily visually recognize the operation information Ic and the notification information Ii. In addition, regardless of the rotation angle of the steering wheel 1, the touch operation position is maintained, so the driver can easily operate the operation information Ic.

[0031] In step S12, the controller 50 selects the linked display mode. The linked display mode is one of the display modes for displaying information on the display 20. As shown in FIGS. 6 and 7 , the linked display mode is a display mode for displaying information in a rotating coordinate system X2Y2 in which the coordinate system rotates in accordance with the rotation angle of the steering wheel 1. The rotating coordinate system X2Y2 is defined by an X2 axis and a Y2 axis that are orthogonal to each other on a plane including the display 20. The origin of the rotating coordinate system X2Y2 coincides with the rotation axis 1a (not shown) of the steering wheel 1. In the linked display mode, the controller 50 can recognize the rotation angle of the steering wheel 1 by referring to the steering angle signal Sθ.

[0032] As shown in Figure 6, when the steering wheel 1 is in the neutral position, the reference line 2a of the wheel body 2 and the reference line 3a of the boss portion 3 coincide with the Y2 axis. The controller 50 displays the operation information Ic at a predetermined coordinate position in accordance with the rotating coordinate system X2Y2. As described above, when the linked display mode is selected, the driving assistance function is not operating, so in the examples shown in Figures 6 and 7, the notification information Ii related to the driving assistance function is not displayed.

[0033] The rotating coordinate system X2Y2 is rotated in synchronization with the rotation angle of the steering wheel 1. As shown in Fig. 7 , when the driver rotates the steering wheel 1 from the neutral position, the controller 50 rotates the rotating coordinate system X2Y2 about the origin in accordance with the rotation angle of the steering wheel 1, and displays the operation information Ic in the rotated rotating coordinate system X2Y2. That is, the controller 50 performs coordinate transformation in accordance with the rotation angle of the steering wheel 1, thereby rotating the operation information Ic about the rotation axis 1a by the rotation angle of the steering wheel 1 and displaying it. When the same type of operation information Ic is continuously displayed, the position and orientation of the operation information Ic change in accordance with the rotation angle of the steering wheel 1.

[0034] In this way, in the linked display mode, the operation information Ic is displayed in a rotated state in accordance with the rotation angle of the steering wheel 1. When the driving assistance function is not activated, the driver grips the steering wheel 1, and therefore the position of the driver's hand 200 also moves in accordance with the rotation of the steering wheel 1. At this time, since the operation information Ic rotates in accordance with the movement of the driver's hand 200, the driver does not feel uncomfortable even when the operation information Ic is rotating, and it is easy for the driver to guess the position at which the information is displayed. Therefore, the driver can properly view the operation information Ic. In addition, since the relative positional relationship between the operation information Ic and the driver's hand 200 is maintained, the driver can operate the operation information Ic on the display 20 without looking at the steering wheel 1.

[0035] 6 and 7 show a form in which notification information Ii related to the driving assistance function is not displayed. However, the controller 50 may display necessary information as notification information Ii. In this case, the display of the notification information Ii is controlled in the same manner as the above-mentioned operation information Ic.

[0036] Drivers grip the steering wheel 1 in various ways. As shown in Figure 8, some drivers grip the steering wheel 1 so that their fingers hang over the display 20. This can cause the driver's fingers to rest on the operation information Ic, resulting in an operation that the driver does not intend. Therefore, the controller 50 learns how the driver grips the steering wheel 1 and performs processing to suppress erroneous operation in steps S13 and S14.

[0037] In step S13 of Fig. 3, the controller 50 learns the grip position based on the steering grip signal Ss and the touch signal St. Specifically, as shown in Fig. 9, the controller 50 detects a grip area Rh of the wheel body 2 held by the driver and a contact area Ra where the driver is touching the touch panel of the display 20. Then, the controller 50 associates the grip area Rh with the contact area Ra and stores the association in a storage area such as a memory.

[0038] In step S14, the controller 50 sets a dead zone on the display 20 where touch operations are invalid. Specifically, the controller 50 recognizes the area of ​​the wheel body 2 currently being gripped by the driver based on the steering grip signal Ss. The controller 50 then refers to the storage area and reads out the contact area Ra associated with the current grip area. The controller 50 sets the contact area Ra as a dead zone where touch operations are invalid.

[0039] This series of processes is repeated at a predetermined interval, and information is displayed on the display 20 in accordance with the selected display mode.

[0040] Below, a modified example in the fixed display mode will be described.

[0041] (First Modification) In the fixed display mode, the operation information Ic is displayed in a state where it does not rotate in accordance with the rotation angle of the steering wheel 1, but the steering wheel 1, i.e., the display 20, is rotating. The driver touches the operation information Ic displayed on the display 20. When the rotation speed of the steering wheel 1 is high, the driver's finger may be dragged or flicked off the rotating display 20, which may result in poor operation. Therefore, the controller 50 may switch between displaying and not displaying the operation information Ic depending on the rotation speed of the steering wheel 1. Specifically, the controller 50 displays the operation information Ic on the display 20 when the rotation speed of the steering wheel 1 is equal to or less than a predetermined threshold. On the other hand, the controller 50 does not display the operation information Ic on the display 20 when the rotation speed of the display 20 is higher than the threshold. This method prevents the driver from touching the operation information Ic when the rotation speed of the steering wheel 1 is high. This makes it possible to prevent the driver's finger from being dragged or flicked off the rotating display 20.

[0042] (Second Modification) The driving assistance function has multiple assistance levels, for example, five levels. In level 1 driving assistance, either driving force and braking force control or steering control is performed by the assistance system, thereby automating either accelerator and brake operation or steering operation. Examples of level 1 driving assistance functions include ACC (Adaptive Cruise Control) and lane keep assist. ACC is a function that performs constant speed driving at a set speed set by the driver and follows a preceding vehicle while maintaining a predetermined distance from the preceding vehicle. Lane keep assist is a function that assists in maintaining the vehicle in its lane. In level 1 driving assistance, the driver must hold the steering wheel 1 with his / her hands 200. In level 2 driving assistance, both driving force and braking force control and steering control are performed by the assistance system, thereby automating both accelerator and brake operation and steering operation. In level 2 driving assistance, the driver can take his / her hands 200 off the steering wheel 1.

[0043] In level 3 driving assistance, the assistance system takes over all driving operations in limited areas where specific driving environment conditions are met. However, if there is a risk that the assistance system will not function properly while driving assistance is in operation, the driver must still perform driving operations. In level 3 driving assistance, the driver can take their hands 200 off the steering wheel 1 and can take their eyes off the road, etc. In level 4 driving assistance, the assistance system takes over all driving operations in limited areas where specific driving environment conditions are met. In level 5 driving assistance, the assistance system takes over all driving operations. In driving assistance from level 4 onwards, the driver can not only take their hands 200 off the steering wheel 1, but also does not need to think about driving operations.

[0044] In such a driving assistance function, the controller 50 may switch the information display mode according to the assistance level of the driving assistance function while maintaining the fixed display mode as a base. That is, when the controller 50 determines that the driving assistance function is activated, the controller 50 may select the linked display mode according to the assistance level of the driving assistance function while maintaining the fixed display mode as a base. Specifically, the controller 50 selects the linked display mode when a driving assistance function of level 1 is activated. On the other hand, the controller 50 selects the fixed display mode when a driving assistance function of level 2 or higher is activated. In this way, the controller 50 may display information in the fixed display mode under the condition that the driving assistance function is level 2 or higher, i.e., driving assistance in which the driver can take his / her hands 200 off the steering wheel 1.

[0045] The level of the driving assistance function is dynamically switched depending on the driving environment, etc. Hereinafter, switching of the display mode will be described using an example in which the driving assistance function is switched from level 1 to level 2. As shown in FIG. 10 , when the driving assistance function is at level 1, the controller 50 displays the operation information Ic in the linked display mode. When the driving assistance function is switched from level 1 to level 2, the controller 50 switches the display mode as follows. First, the controller 50 disables touch operations on the display 20 for a certain period of time. At this time, as shown in FIG. 11 , to indicate that operations on the operation information Ic are disabled, the controller 50 displays the operation information Ic in a display mode different from the normal display mode, for example, grayed out. Then, the controller 50 switches the display mode from the linked display mode to the fixed display mode. As shown in FIG. 12 , the controller 50 enables touch operations on the display 20 and returns the operation information Ic from grayed out to the normal display mode.

[0046] The above description has been given with reference to an example of a situation in which the display mode is switched from the linked display mode to the fixed display mode. However, the above method can also be applied when the display mode is switched from the fixed display mode to the linked display mode. That is, when the display mode is switched from the fixed display mode to the linked display mode, the controller 50 disables touch operations on the display 20 for a certain period of time (transition from FIG. 12 to FIG. 11). Then, after the display mode is switched from the fixed display mode to the linked display mode, the controller 50 enables touch operations on the display 20 (FIG. 10).

[0047] (Third Modification) The driving assistance function is not limited to a travel assistance function as long as it is a function that assists the driver in driving. For example, the driving assistance function may be a parking assistance function that assists in parking the vehicle. In this case, similar to the process shown in FIG. 3 , the controller 50 determines whether the parking assistance function is operating. If the parking assistance function is operating, the controller 50 selects the fixed display mode, and if the parking assistance function is not operating, the controller 50 selects the linked display mode.

[0048] In such a parking assist function, the controller 50 may switch the display mode based on the fixed display mode, but may also switch the display mode depending on the assistance process performed by the parking assist function. That is, when the controller 50 determines that the parking assist function is operating, the controller 50 may also select the linked display mode based on the fixed display mode, but may also select the linked display mode depending on the assistance process. Specifically, the assistance process performed by the parking assist function includes a parking position search state, a standby state before parking starts, a driving state during parking control execution, a temporary suspension state of parking control, and a parking completion state. The parking position search state is a state in which the driver performs driving operations to search for a parking position (parking position). The standby state before parking starts is a state in which the driver performs driving operations and stops the vehicle in front of a parking position. The driving state during parking control execution is a state in which the assistance system automatically performs any of driving force control, braking force control, steering control, and shift control, thereby driving the vehicle toward a parking position. The temporary suspension state of parking control is a state in which parking control is temporarily suspended. The parking completion state is a state in which the vehicle has been parked in the parking position. Among these assistance processes, in the driving state during the parking control execution and the parking control temporary suspension state, the driver can release the hands 200 from the steering wheel 1.

[0049] As shown in Fig. 13 , the controller 50 displays information in the linked display mode when the assistance process of the parking assistance function is in a parking position search state. Similarly, the controller 50 displays information in the linked display mode when the assistance process of the parking assistance function is in a standby state before parking starts. On the other hand, as shown in Fig. 14 , the controller 50 displays information in the fixed display mode when the assistance process of the parking assistance function is in a driving state during execution of parking control. Similarly, the controller 50 displays information in the fixed display mode when the assistance process of the parking assistance function is in a state in which parking control is temporarily suspended. Then, when the assistance process of the parking assistance function has reached a parking completion state, the controller 50 displays information in the linked display mode. In this way, the controller 50 may display information in the fixed display mode under the condition that the driver is in a process of the parking assistance function in which he or she can take his or her hands 200 off the steering wheel 1.

[0050] When switching the display mode from the linked display mode to the fixed display mode, or when switching the information display mode from the fixed display mode to the linked display mode, as described above, the controller 50 may disable touch operations on the display 20 for a certain period of time.

[0051] As described above, in the display method according to this embodiment, the controller 50 determines whether a driving assistance function (cruising assistance function, parking assistance function) that assists the driver in driving is operating. If the controller 50 determines that the driving assistance function is operating, the controller 50 displays information in a state that does not rotate in accordance with the rotation angle of the steering wheel 1. According to this method, the position and orientation of the information are maintained regardless of the rotation angle of the steering wheel 1. When the driving assistance function is operating, the driver can remove his / her hands 200 from the steering wheel. Even if the steering wheel 1 is rotated, the information is displayed in a state that does not rotate, so the driver can properly view the information. In this way, by displaying information in an appropriate manner according to the state of the vehicle, the information can be displayed in a form that is easy for the driver to see.

[0052] In the display method of this embodiment, the driving assistance function is a driving assistance function that assists driving on a lane of a road and has multiple assistance levels. When the controller 50 determines that the driving assistance function is operating, it switches the information display mode depending on the assistance level of the driving assistance function. Alternatively, in this embodiment, the driving assistance function is a parking assistance function that assists parking of the vehicle. When the controller 50 determines that the parking assistance function is operating, it switches the information display mode depending on the process of assistance performed by the parking assistance function.

[0053] Depending on the assistance level of the driving assistance function or the assistance process executed by the parking assistance function, there are situations in which the driver can take his / her hands 200 off the steering wheel and situations in which he / she cannot take his / her hands 200 off the steering wheel. Therefore, by switching the display mode depending on the assistance level or the assistance process, it is possible to display information in an appropriate manner. In this way, by displaying information in an appropriate manner depending on the state of the vehicle, it is possible to display information in a form that is easy for the driver to see.

[0054] In the display method of this embodiment, the display 20 is a touch panel display that can be touched by the driver. Information displayed on the display 20 is operation information Ic that allows the driver to give operational instructions.

[0055] In the fixed display mode, the position and orientation of the operation information Ic are maintained regardless of the rotation angle of the steering wheel 1. Therefore, the touch operation position is maintained the same regardless of the rotation angle of the steering wheel 1, allowing the driver to easily operate the operation information Ic.

[0056] In the display method of this embodiment, when the display mode is switched, the controller 50 disables touch operations on the display 20 for a certain period of time, and after the display mode is switched, enables touch operations on the display 20. According to this method, touch operations by the driver are disabled when the display position of information is switched, so that erroneous operations by the driver can be prevented.

[0057] In the display method of this embodiment, the display 20 has an annular shape and is arranged concentrically with the rotation axis 1a of the steering wheel 1. According to this method, even when the steering wheel 1 rotates in response to steering, information can be displayed in the same position and orientation regardless of the rotation angle of the steering wheel 1.

[0058] In this embodiment, the annular display 20 is disposed around the boss portion 3. However, the display 20 may be a circular display disposed concentrically with the rotation axis 1 a of the steering wheel 1 so that the entire inside of the wheel body 2 is the display 20.

[0059] In this embodiment, the display 20 is a transparent display, so that vehicle elements behind the display 20, such as the instrument unit 100, can be seen through the display 20.

[0060] However, the display 20 may be a non-transparent display. In this case, it is preferable that the controller 50 uses the display 20 to display blind spot information indicating vehicle elements in the driver's blind spot. The vehicle elements in the blind spot are, for example, information about the instrument unit 100, and the blind spot information is information indicating the instrument unit 100 and displaying the status of the instruments provided in the instrument unit 100 in real time. This prevents the instrument unit 100 from being hidden by the display 20. Furthermore, when such a non-transparent display is used, it is possible to omit the actual instrument unit 100 by displaying information about the instrument unit 100.

[0061] The controller 50 preferably displays the blind spot information in an area above the center of the steering wheel 1 so as to match the actual view seen by the driver. Furthermore, the blind spot information represents vehicle elements whose positions are fixed in the vehicle. Therefore, the controller 50 preferably displays the blind spot information in a fixed coordinate system X1Y1, regardless of whether the driver is gripping the steering wheel 1. Additionally, the controller 50 preferably displays the blind spot information in a layer that is closer to the background than the operation information Ic. In this case, the controller 50 preferably masks the blind spot information with the operation information Ic in the area where the blind spot information and the operation information Ic overlap. This method can reproduce an appearance similar to that of a conventional steering wheel not provided with a display 20. This makes it possible to provide a steering wheel 1 that feels natural to the driver.

[0062] In this embodiment, the operation information Ic includes sixth operation information Icf for operating turn signals, which are displayed on the left and right sides of the rotation axis of the steering wheel 1. The sixth operation information Icf is also displayed on the left and right sides corresponding to the left and right turn signals. This makes it easier for the driver to visually recognize whether the left and right sixth operation information Icf is information for operating the right or left turn signal. In addition, the driver can operate the left and right sixth operation information Icf with their right and left hands, respectively, thereby improving operability.

[0063] In this embodiment, the operation information Ic includes text. According to the method of this embodiment, when it is determined that the driving assistance function is operating, the information is displayed in a state where it does not rotate in accordance with the rotation angle of the steering wheel 1 (in a state where the position and orientation are fixed). Therefore, even if the steering wheel 1 is rotated, the text is always displayed horizontally, making it easier for the driver to read the text.

[0064] In this embodiment, the controller 50 learns how the driver grips the steering wheel 1 and sets a dead zone in which touch operations are disabled based on the learning results. This method allows the dead zone to be set taking into account the individual habits or characteristics of the driver, thereby effectively suppressing erroneous operations by the driver.

[0065] From the viewpoint of preventing driver's erroneous operation, the manner in which the driver grips the steering wheel 1 may be learned, and the position and size of the operation information Ic may be changed based on the learning results so as to avoid the contact area Ra.

[0066] Second Embodiment A display method and a display system according to a second embodiment will be described below. Explanations that overlap with the first embodiment will be omitted, and differences will be mainly described. A display method according to this embodiment will be described with reference to FIG. 15. The flowchart shown in FIG. 15 is periodically executed by the controller 50.

[0067] In step S20, the controller 50 determines whether the driver is gripping the steering wheel 1. Specifically, the controller 50 references the driving assistance signal Sp to determine whether a driving assistance function that allows the driver to release their hands from the steering wheel 1 is active. If the driving assistance function is active, the controller 50 references the steering grip signal Ss to determine whether the driver is gripping the steering wheel 1. If the driver is not gripping the steering wheel 1 (step S20: NO), the controller 50 selects the fixed display mode. On the other hand, if the driver is gripping the steering wheel 1 (step S20: YES), the controller 50 selects the linked display mode. Details of each display mode are the same as in the first embodiment. Furthermore, if the linked display mode is selected, the controller 50 stores the grip position and performs a dead zone setting process (S23, S24), as in the first embodiment.

[0068] As described above, in the second embodiment, when the controller 50 determines that the driver is gripping the steering wheel 1, the controller 50 displays the operation information Ic in accordance with the rotation angle of the steering wheel 1. When the driver is gripping the steering wheel 1, the information also rotates in accordance with the movement of the driver's hand 200 operating the steering wheel 1, so that the driver can naturally accept the rotation of the information and easily recognize the position and orientation. In this way, by displaying information in an appropriate manner in accordance with the driving situation of the driver gripping the steering wheel 1, the information can be displayed in a form that is easy for the driver to see.

[0069] The first and second embodiments have been described above. A display system 10 including a display 20 fixed to a steering wheel 1 that steers the vehicle's wheels and a controller 50 that displays information on the display 20 is also included as part of the present embodiments. The controller 50 performs the above-described display method. This display system displays information in an appropriate manner depending on the vehicle's situation, allowing the driver to efficiently recognize the information.

[0070] Although the embodiments of the present invention have been described above, the descriptions and drawings that form part of this disclosure should not be understood to limit the present invention. Various alternative embodiments, examples, and operating techniques will become apparent to those skilled in the art from this disclosure.

[0071] 1: Steering wheel, 2: Wheel body, 3: Boss portion, 10: Display system, 20: Display, 50: Controller, 100: Instrument unit, Ic: Operation information, Ii: Notification information

Claims

1. A display method for displaying information on a display fixed to the center of a steering wheel that steers the steering wheels of a vehicle, which determines whether a driving assistance function that assists the driver in driving is operating, and if it is determined that the driving assistance function is operating, displays the information in a state that does not rotate in accordance with the rotation angle of the steering wheel.

2. A display method as claimed in claim 1, wherein the display modes for displaying the information on the display include a fixed display mode in which the information is displayed without rotating in accordance with the rotation angle of the steering wheel, and a linked display mode in which the information is displayed in a state in which it is rotated in accordance with the rotation angle of the steering wheel, and the driving assistance function is a parking assistance function that assists in parking the vehicle, and when it is determined that the parking assistance function is operating, the display mode is switched in accordance with the process of assistance performed by the parking assistance function.

3. A display method as claimed in claim 1, wherein the display modes for displaying the information on the display include a fixed display mode in which the information is displayed without rotating in accordance with the rotation angle of the steering wheel, and a linked display mode in which the information is displayed in a state in which it is rotated in accordance with the rotation angle of the steering wheel, and the driving assistance function is a driving assistance function that assists driving on lanes of a road and has a plurality of assistance levels, and when it is determined that the driving assistance function is operating, the display mode is switched in accordance with the assistance level of the driving assistance function.

4. The display method according to claim 2 or 3, wherein the display is a touch panel display that can be operated by the driver through touch, and the information is operation information for the driver to give an operation instruction.

5. The display method according to claim 4, wherein, when the display mode is switched from the fixed display mode to the linked display mode, touch operations on the display are disabled for a certain period of time, and after the display mode is switched from the fixed display mode to the linked display mode, touch operations on the display are enabled.

6. A display method according to claim 4 or 5, wherein, when the display mode is switched from the linked display mode to the fixed display mode, touch operations on the display are disabled for a certain period of time, and after the display mode is switched from the linked display mode to the fixed display mode, touch operations on the display are enabled.

7. The display method according to claim 4, wherein, when the driver is gripping the steering wheel, the operation information is displayed in a rotated state in accordance with the rotation angle of the steering wheel.

8. A display method according to any one of claims 1 to 7, wherein the display has a circular or annular shape and is arranged inside the steering wheel concentrically with the axis of rotation of the steering wheel.

9. The display method according to claim 3, wherein the display is a transparent display or a non-transparent display, and when the display is a non-transparent display, the display displays blind spot information indicating vehicle elements that are in the driver's blind spot.

10. The display method according to claim 7, wherein the operation information includes information for operating a turn signal, which is displayed on the left and right sides of the rotation axis of the steering wheel.

11. The display method according to claim 7 or 10, wherein the operation information includes characters.

12. The display method according to any one of claims 7, 10 and 11, further comprising: learning how the driver grips the steering wheel; and setting a dead zone in which the touch operation is treated as invalid based on the learning result.

13. A display method as claimed in claim 4, wherein, in the fixed display mode, when the rotation speed of the steering wheel is equal to or less than a threshold, the operation information is displayed on the display, and, in the fixed display mode, when the rotation speed of the steering wheel is greater than the threshold, the operation information is not displayed on the display.

14. A display system comprising: a display fixed to the center of a steering wheel that steers the steering wheels of a vehicle; and a controller that displays information on the display, wherein the controller determines whether a driving assistance function that assists the driver in driving the vehicle is operating, and if it determines that the driving assistance function is operating, displays the information in a state that does not rotate in accordance with the rotation angle of the steering wheel.

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