FIELD OF INVENTION

[0001] The present subject matter described herein generally relates to a parking assist system for a two-wheeled vehicle, and particularly but not exclusively relates to a control method thereof.

BACKGROUND OF INVENTION

[0002] Parking a vehicle is often challenging for drivers as it involves maneuvering between other parked vehicles, especially in crowded roads. Whereas in some cases, it requires maneuvering between two vehicles parked in an end to end manner, in some other cases it requires the vehicle to be maneuvered between two vehicles parked parallel to each other in a side by side manner. Typically, few factors that affect maneuverability include size of the vehicle being parked, turning radius of the vehicle being parked, speed of the vehicle while parking and the like.

[0003] In order to facilitate a driver in ease of parking, typically four wheeled vehicles are provided with parking assist systems which guide the driver to park the vehicle correctly by indicating to the driver the present direction that the vehicle is travelling in with respect to the parked vehicles. However, parking assist systems are not typically used in for two-wheeled vehicles and they are typically pushed manually to be parked; such as a vehicle which is configured to be powered either by an internal combustion engine or a traction motor or both, and an electric vehicle powered by a traction motor. Additionally, compared to normal two-wheeled vehicles, hybrid/electric two-wheeled vehicles are harder to push owing to greater cogging torque of the traction motor. Moreover, hybrid two-wheeled vehicles are also significantly heavier than normal two-wheeled vehicles. As a result, pushing said hybrid/electric vehicle into a parking slot proves to be cumbersome. Moreover, since typically the initial powering/acceleration provided in hybrid/electric two-wheeled vehicles is higher, controlling said vehicle for parking becomes difficult.

[0004] Some prior arts teach the use of parking assist systems in two-wheeled hybrid/electric vehicle. However, there are some problems in the known parking assist systems. For example, in some hybrid/electric vehicles in which a parking assist system is known, a parking indication system to intimate other motorists or pedestrians or even to the vehicle operator himself that the vehicle is moving in a parking mode especially in the reverse direction is unknown. Absence of the parking indication system thus proves to be a safety hazard. Moreover, in some hybrid/electric vehicles, operation of the parking assist system to facilitate reverse parking by movement of the vehicle in the reverse direction is known wherein the parking assist system is activated with the mere press of a button/parking switch. However, such vehicles face the danger of automatically moving in the reverse direction if the vehicle operator inadvertently presses the parking switch. [0005] It is therefore desirable to provide a parking assist system for a two- wheeled vehicle, especially for two-wheeled hybrid/electric vehicles with improved safety features.

[0006] It is therefore desired to address the problems encountered in the background as discussed above. BRIEF DESCRIPTION OF DRAWINGS

[0007] The detailed description of the present subject matter is described with reference to the accompanying figures. Same numbers are used throughout the drawings to reference like features and components.

[0008] Figure 1 illustrates a schematic representation of a two-wheeled vehicle in accordance with an embodiment of the present invention. [0009] Figure 2 is a schematic representation of the parking assist system in accordance with an embodiment of the present invention.

[00010] Figure 3 illustrates a flow chart depicting steps of a method of functioning of the parking assist system in accordance with an embodiment of the present invention. DETAILED DESCRIPTION

[00011] The present invention has been devised in view of the above stated problems.

[00012] It is an object of the present invention to provide a parking assist system for a two- wheeled vehicle. [00013] It is another object of the present invention to provide a parking assist system for a two-wheeled vehicle capable of assisting movement of said vehicle in a forward or a reverse direction in a parking assist mode.

[00014] It is yet another object of the present invention to provide a parking assist system including an electronic control unit configured to control power delivered to a traction motor of said vehicle for powering said vehicle in either a forward direction or a reverse direction.

[00015] It is still another object of the present invention to provide a parking assist system including an electronic control unit configured to send parking indication signal to an instrument cluster for intimation of selection of parking assist mode. [00016] It is one more object of the present invention to provide a parking assist system including an electronic control unit configured to send a parking signal to a plurality of hazard lamps of said vehicle for intimation of selection of parking assist mode.

[00017] With the above and other objects in view, the present invention provides a two-wheeled vehicle including a parking assist system for assisting movement of said vehicle in a forward or reverse direction in a parking assist mode. As per an aspect of the present invention, the parking assist system includes an electronic control unit which aids in assisting the movement of said vehicle in the forward or reverse direction in the parking assist mode. Particularly, said electronic control unit serves to assist said vehicle in the parking assist mode by controlling an output power delivered to a traction motor of said vehicle. For example, said electronic control unit, serves to control the output power delivered to the traction motor of said vehicle based on various vehicle parameters such as vehicle speed, throttle position, brake condition and the like, which is received from vehicle sensors such as hall sensor, throttle position sensor, brake switch and the like; so that a vehicle operator has better control over the vehicle while parking.

[00018] Particularly, as per an embodiment of the present invention, said electronic control unit serves to control output power delivered to the traction motor when a parking switch of said vehicle is in an ON state and one of a first set of predetermined conditions and a second set of predetermined conditions is satisfied. In one embodiment, said first set of predetermined conditions is satisfied when the vehicle speed is below a first threshold vehicle speed, and the throttle position is in an open state. Thus, when said control unit detects the first set of predetermined conditions, said control unit causes said vehicle to operate in the parking assist mode in a forward direction. Therefore, since the output power delivered to the traction motor is controlled, it is ensured that said vehicle moves at a first pre-selected speed lesser than the first threshold vehicle speed. In other words, said vehicle is caused to move at a lower speed when it is operating in the parking assist mode, thereby giving a vehicle operator a better control over the vehicle during parking and enabling easy maneuvering of vehicle during parking.

[00019] Similarly, said electronic control unit serves to control output power delivered to the traction motor when the second set of predetermined conditions are satisfied, and causes said vehicle to move in a reverse direction. As per an embodiment of the present invention, said second set of predetermined conditions are satisfied when the vehicle speed is zero, throttle position is in a closed state, brake is in OFF condition, and an angle of rotation attained of a rear wheel of said vehicle is a predefined degree of rotation, say for example quarter turn of rotation of rear wheel. In other words, said second set of predetermined conditions are satisfied when said vehicle is manually pushed backwards, whereby the electronic control unit detects the quarter reverse turn of the rear wheel and causes said vehicle to move in the reverse direction. Thus, when the vehicle operator pushes said vehicle in the reverse direction for parking, the electronic control unit automatically causes said vehicle to move in the reverse direction at a second pre-selected speed. Provision of the above feature also aids in easily taking out the vehicle from a parked condition. As per an embodiment of the present invention, said second pre-selected speed of the vehicle is lesser than the first pre-selected speed. In other words, the vehicle is caused to move at a lower speed in the reverse direction in comparison to the speed in the forward direction, thereby ensuring safety of the vehicle and the vehicle operator. However, at the same time since minimal amount of power is supplied to the traction motor, it is ensured that the vehicle can be moved without much effort in the reverse direction, which would otherwise be difficult to push manually, especially in up-hill conditions. Particularly, since a manual intervention of pushing said vehicle in the reverse direction is involved for said electronic control unit to power said vehicle in the reverse direction, it is ensured that there is no inadvertent movement of said vehicle in the reverse direction with the mere press/selection of the parking switch.

[00020] As per another aspect of the present invention, said parking switch is combined with a hazard switch in said two-wheeled vehicle. Therefore, when said parking switch is switched ON, a plurality of hazard lamps begin to glow. Thus, it is ensured that passers-by/pedestrians are alerted when said vehicle is operating in the parking assist mode.

[00021] As per one more aspect of the present invention, a parking indication signal is communicated to the instrument cluster of said vehicle from said electronic control unit. Particularly, whereas in one embodiment said parking indication signal provided to the instrument cluster may be a visual indication including text and color indication; in another embodiment said parking indication signal provided may be an auditory indication. [00022] Further, the present invention also describes a method of operation of said electronic control unit for controlling output power delivered to the traction motor when the parking switch is switched ON.

[00023] Summary provided above explains the basic features of the invention and does not limit the scope of the invention. The nature and further characteristic features of the present invention will be made clearer from the following descriptions made with reference to the accompanying drawings.

[00024] Thus, the present subject matter described herein relates to a parking assist system for a two wheeled vehicle which enables ease of vehicle parking while ensuring that safety measures are in place. Particularly, said parking assist system includes an electronic control unit such as a hybrid control unit for controlling output power delivered to a traction motor, so that said vehicle can operate in a parking assist mode in a forward direction or a reverse direction at one of a first pre- selected speed and a second pre-selected speed. [00025] Exemplary embodiments detailing features of the parking assist system in accordance with the present invention will be described hereunder. The embodiments described herein apply to a vehicle powered by two or more power sources including an internal combustion engine, traction motor and a battery. However, the present invention is not restricted in its application and is also applicable to vehicles employing only the traction motor and the battery, say for example an electric vehicle.

[00026] Arrows provided in the top right corner of each figure depicts direction with respect to the vehicle, wherein an arrow F denotes front direction, an arrow R indicates rear direction, an arrow Up denotes upward direction, an arrow Dw denotes downward direction, an arrow Rh denotes right side, an arrow Lh denotes left side, as and where applicable.

[00027] The present invention has been exemplified for a hybrid two-wheeled vehicle as illustrated in FIG.1. [00028] With reference to FIG. 1, a description is made of a hybrid two-wheeled vehicle 10 in accordance with an embodiment of the present invention. FIG.1 is a side view of said hybrid vehicle 10. Said vehicle 10 illustrated, has a step-through type frame assembly. The step-through type frame assembly includes a head tube 15A, a main tube 15B and a pair of side tubes 15C. Particularly, the main tube 15B extends downwards from a rear portion of the head tube 15A and then extends rearwards in an inclined manner. Further, the pair of side tubes 15C extends inclinedly upwardly from the main tube 15B. Thus, the frame assembly extends from a front portion to a rear portion of the vehicle. [00029] Said hybrid vehicle 10 further includes a plurality of body panels for covering said frame assembly, and is mounted thereto. In the present embodiment said plurality of panels includes a front panel 15FP, a leg shield 15LS, an under-seat cover 15SC, and a left and a right side panel 15SP. Further, a glove box may be mounted to said leg shield 15LS. [00030] In a step through space formed between said leg shield 15LS and said under seat cover 15SC, a floorboard 12 is provided. Further, a seat assembly 25 is disposed above said under-seat cover 15SC, and is mounted to the pair of side tubes 15C. A utility box (not shown) is disposed below the seat assembly 25. A fuel tank (not shown) is positioned at one end of the utility box. A rear fender 26 for covering at least a portion of a rear wheel 27 is positioned below the utility box.

[00031] One or more suspension(s)/shock absorbers 30 are provided in a rear portion of said vehicle 10 for comfortable ride. Further said vehicle 10 comprises of plurality of electrical and electronic components including a headlight 35A, a taillight 35B, a transistor controlled ignition (TCI) unit (not shown), a starter motor (not shown) and the like. A touch screen LCD unit (not shown) is provided on a handle bar 11 to display various operating modes, power flow pattern and warning signals. Rear view mirrors 13 are mounted on the right and left sides of the handle bar 11. Said vehicle 10 is also provided with hazard lamps (not shown). [00032] An internal combustion engine 14, hereinafter D engineD , is arranged behind said floorboard 12 and supported between the pair of side tubes 15C. Particularly, said internal combustion engine 14 is supported by a swing arm 19. The swing arm 19 is attached to a lower portion of the main tube 15B by means of a toggle link (not shown). The other end of the swing arm 19 holds the rear wheel 27. The rear wheel 27 and the swing arm 19 are connected to the pair of side frames 15C by means of one or more shock absorbers 30 provided on either side of said vehicle 10.

[00033] Said hybrid vehicle 10 further includes a traction motor 53 mounted on a hub of the rear wheel 27. Said traction motor 53 is powered by a battery (not shown) disposed in a rear portion of the vehicle. However, in another embodiment, the battery may be disposed in a front portion of the vehicle. An electronic control unit 50 (shown in FIG2) is also provided to control various vehicle operative modes.

[00034] Said hybrid vehicle 10 is configured to be propelled either by the engine 14 alone or by the traction motor 53 alone or by both engine 14 and traction motor 53 simultaneously. At zero vehicle speed, a rider can select any of the following four operating drive modes with the help of a mode switch. The four operating drive modes of the hybrid vehicle 10 are: (a) a sole engine mode where engine 14 alone powers the vehicle (b) a sole motor mode where the traction motor 53 alone powers the vehicle (c) a hybrid power mode wherein the engine 14 and the traction motor 53 together power the hybrid vehicle 10 (d) a hybrid economy mode wherein only the engine 14 or only the traction motor 53 or both power the hybrid vehicle depending on the vehicle operating conditions.

[00035] In other words, the rear wheel 27 of the vehicle is driven by either the engine 14 alone or by the motor 53 alone or by both the engine 14 and the motor 53 simultaneously. Particularly, power from the engine 14 to the rear wheel 27 is transmitted by a transmission assembly including a drive system (not shown) as per an embodiment of the present invention. However, when the traction motor 53 drives, power from the motor 53 is directly transmitted to the rear wheel 27. In the present embodiment, said traction motor 53 is covered by a motor shroud (not shown) from at least one side.

[00036] Said vehicle 10 as described above is adapted to operate in a parking assist mode by means of a parking assist system P provided therein. [00037] Referring to FIG.2, description is made of a schematic representation of the parking assist system P as per an embodiment of the present invention. The parking assist system P includes the electronic control unit 50 which is configured to be communicatively connected with various other components such as the instrument cluster 52, the traction motor 53, the battery 60, and to a plurality of vehicle sensors and vehicle switches including ignition switch 51, a throttle position sensor 54, a brake switch 55, parking switch 56 and the like, in order to receive various inputs relating to vehicle operating conditions. Particularly, said electronic control unit 50 communicates with the above mentioned components, sensors and switches via controller area network (CAN) communication. Some of the above mentioned components such as the battery 60, and the instrument cluster 52 may include their own controllers. For example, the battery 60 may have a battery control module (BCM) or a battery management system (BMS) that sends and receives signals to and from the battery 60 and the electronic control unit 50. In the present embodiment, said instrument cluster 52 includes a first microcontroller for communication with the electronic control unit 50. Further, the traction motor 53 is integrated with one or more hall sensors for communication with the electronic control unit 50. Further, the electronic control unit 50 is operatively connected to the battery 60 and the traction motor 53. While the battery 60 powers the electronic control unit 50, power delivered to the traction motor 53 from the battery 60 is controlled by the electronic control unit 50. [00038] In the present embodiment, the instrument cluster 52 includes a first microcontroller which is communicatively connected to the electronic control unit 50 having a second microcontroller through CAN communication. The electronic control unit 50, based on the information received from said plurality of vehicle sensors/switches, provides vehicle information, which in turn is processed by the first microcontroller in order to be displayed in the instrument cluster 52. The instrument cluster 52 provides to the vehicle operator a variety of vehicle operation related information, for example, drive mode operation, parking mode operation, state of charge of battery and the like. In doing so, the instrument cluster 52 represents said vehicle in a schematic or iconic representation. Said schematic or iconic representation provides the vehicle operator with a better idea about how the vehicle is operating and if there is any malfunctioning in the vehicle, and is therefore more relevant and useful than a conventional analog or digital display device.

[00039] For example, in the present embodiment, when said electronic control unit 50 activates a parking assist mode, the same is communicated to the instrument cluster 52 and a visual indication in the form of a visual text is provided in the instrument cluster 52 for intimating the vehicle operator about the operation of the vehicle in said parking assist mode. Moreover, when the parking switch 56 is selected, a signal is sent to a plurality of hazard lamps 57 and said plurality of hazard lamps 57 begin to glow, giving a warning to other vehicles/pedestrians that vehicle would be slow moving.

[00040] The method of functioning of the parking assist system P in accordance with an embodiment of the present invention is elaborated with reference to FIG3. Particularly, FIG.3 denotes steps of operation of the first microcontroller in the instrument cluster 52 and that of the electronic control unit 50 for operating said vehicle in the parking assist mode. At the outset, it is to be noted that some steps in flowchart 99 may be performed in a different sequence, including concurrently. In addition, the steps shown in the flowchart 99 are ongoing, and do not end necessarily at the last step.

[00041] In a first step of its operation at block 100, the electronic control unit 50 determines if the ignition switch 51 is in an ON/OFF state. In a condition when the ignition switch is in ON state, and when the vehicle operator switches ON the parking switch, the first microcontroller in the instrument cluster 52 detects the ON state of the parking switch at block 101 and selects the parking assist mode at block 102. Particularly, as per an aspect of the present invention, when the parking switch is selected, the parking switch input is sent to the instrument cluster. The parking mode signal is also sent to the plurality of hazard lamps, resulting in glowing of the hazard lamps. Thereafter, the first microcontroller of the instrument cluster at block 103 also communicates with the electronic control unit via CAN communication that the parking assist mode is selected. In other words, it is communicated via CAN communication that vehicle drive mode has been changed to parking assist mode. In a condition when parking assist mode has not been selected by switching ON the parking switch, the vehicle continues to operate in the existing drive mode. Further, when the electronic control unit detects that the parking assist mode is selected, it determines if the existing vehicle operating conditions are suitable for the vehicle to operate in the parking assist mode. For example, as per an aspect of the present invention, the electronic control unit checks whether a first set of predetermined conditions or a second set of predetermined conditions are satisfied in order to enable operation of the vehicle in the parking assist mode. As per an embodiment, while the first set of predetermined conditions are set out in block 104 and 105, the second set of predetermined conditions are set out in blocks 107, 108 and 109. After detection of either the first set of predetermined conditions or the second set of predetermined conditions mentioned as above by ECU, parking mode indication signal is sent to the instrument cluster, whereby the instrument cluster displays D PARKING ASSIST OND in a display panel.

[00042] In the present embodiment, at block 104 the electronic control unit checks for vehicle speed, whether the vehicle speed is zero or below a first threshold speed. If the vehicle speed is zero or below the first threshold speed then the electronic control unit initiates parking assist mode. In other words, the electronic control unit ensures that the selection of parking switch by the vehicle operator is intentional before enabling the parking assist mode. Particularly, in the present embodiment, input regarding vehicle speed is provided to the electronic control unit by one or more hall sensors disposed in the traction motor. In the present embodiment, the first threshold speed may be in the range of 8-10 km/h.

[00043] Further, the electronic control unit checks for throttle position at block 105. If the throttle position is open, the electronic control unit enables the operation of the parking assist mode in a forward direction at a first pre-selected speed in the range of 5- 6 km/h at block 106. Concurrently, a signal is also sent to the instrument cluster for displaying parking sequence in the form of a visual text or in the form of backlight colour etc. [00044] However, if the throttle is closed, the electronic control unit checks for conditions set out in block 107. At block 107, the electronic control unit checks if vehicle speed is zero, throttle position is closed and brake input is in OFF condition. If the conditions set out in block 107 are satisfied, the electronic control unit checks for reverse turn of rear wheel at block 108. The input regarding reverse turn of rear wheel is received by the electronic control unit from said one or more hall sensors disposed in the traction motor. In the present embodiment, when a predetermined angle of rotation, say for example of 90° is detected at the rear wheel, the electronic control unit enables the parking assist mode in reverse direction. In other words, the electronic control unit checks if the vehicle operator has pushed the vehicle at least slightly in reverse direction till a rotation of 90° is attained at the rear wheel, before enabling the parking assist mode in the reverse direction. Further, the electronic control unit also simultaneously checks at block 109 if the vehicle speed is greater than a second threshold speed, say for example greater than 2-3km/h. If the vehicle speed is not greater than the second threshold speed, the electronic control unit enables the operation of the parking assist mode in a reverse direction at a second pre-selected speed in the range of 3-4 km/h. Concurrently, a signal is also sent to the instrument cluster for displaying parking sequence in the form of a visual text or in the form of backlight colour. However, if the vehicle speed is greater than the second threshold speed, the electronic control unit activates electric brake. This is to ensure that the vehicle doesnDt start speeding down due to the additional power provided to the traction motor in the parking assist mode when the vehicle operator is trying to park said vehicle on a down slope. Thus, application of brake when the vehicle speed is greater than the second threshold speed, serves as a safety feature when the vehicle operator is trying to park said vehicle on a down slope. Further, when the parking assist mode in the reverse direction is enabled, the electronic control unit also checks whether current supplied to the traction motor exceeds a threshold current at block 111. If said control unit detects that the current supplied to the traction motor exceeds the threshold current, then said control unit stops current/power supply to the traction motor. This is particularly applicable when the motor encounters greater load; say for example a greater load is encountered when the vehicle operator suddenly tries to stop the vehicle by hand without application of brake in a down-hill condition. Therefore, in order to prevent speeding of the vehicle after crossing the bump, especially in a down-hill condition, the electronic control unit is also configured to detect current/power supplied to the motor greater than threshold current, so that said vehicle moves safely in the reverse direction.

[00045] The present invention therefore provides a method for assisting movement of said two-wheeled vehicle in the parking assist mode in either a forward direction or a reverse direction. Since the present invention aids in optimizing the power delivered to the traction motor when the parking assist mode in enabled, the vehicle operator finds it convenient to handle and maneuver the vehicle during parking. Moreover, since at least some minimal amount of power is supplied to the traction motor, the vehicle operator need not exert himself for pushing the vehicle during parking.

[00046] While the present invention has been shown and described with reference to the foregoing preferred embodiments, it will be apparent to those skilled in the art that changes in form, connection, and detail may be made therein without departing from the spirit and scope of the invention as defined in the appended claims.