Electric vehicle and its automatic control device

Abstract

Improve the convenience of electric vehicles. [Solution] The automatic control device is provided on an electric vehicle V that has a manually operable steering wheel unit 31, steering wheels 11f, and a steering shaft 51 that connects the steering wheel unit 31 and steering wheels 11f and is capable of transmitting operation of the steering wheel unit 31 to the steering wheels 11f. The automatic control device includes a steering coupling 71 that is detachable from the steering shaft 51, and an automatic steering unit U that is attached to the steering shaft 51 via the steering coupling 71. The automatic steering unit U includes an electric motor ACT2 that is a power source for steering, a first power transmission unit 801 that transmits the output torque of the electric motor ACT2 to the steering coupling 71, and a steering controller 804 that controls the operating state of the electric motor ACT2.

Description

[Technical Field]

[0001] The present invention relates to an electric vehicle and an automatic control device thereof. [Background technology]

[0002] There is technology that contributes to automating driving functions, including steering, for electric wheelchairs such as senior cars. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6809129 Summary of the Invention [Problem to be solved by the invention]

[0004] When an existing electric vehicle is equipped with an autonomous driving function, it is common for the vehicle to be transported to a repair shop. This means that the user is left without the vehicle until the installation is complete, which causes inconvenience to the user's daily travel. On the other hand, if an electric vehicle with an autonomous driving function breaks down, the vehicle must also be transported to a shop for repair, which also causes inconvenience to the user.

[0005] In view of the above circumstances, an object of the present invention is to provide an automatic control device that contributes to improving the convenience of electric vehicles, and an electric vehicle equipped with the same. [Means for solving the problem]

[0006] In order to solve the above problems, one aspect of the present invention provides an automatic control device for an electric vehicle having a manually operable handle unit, a steering wheel, and a steering shaft connecting the handle unit and the steering wheel and capable of transmitting operation of the handle unit to the steering wheel, the automatic control device including: a steering coupling detachable from the steering shaft; and an automatic steering unit attached to the steering shaft so as to be capable of transmitting power via the steering coupling. The automatic steering unit includes an electric motor as a power source for steering, a first power transmission unit that transmits output torque of the electric motor to the steering coupling, and a steering controller that controls the operating state of the electric motor.

[0007] An electric vehicle according to another aspect of the present invention includes a handle unit that can be manually operated by a passenger, a steering wheel, a steering shaft that connects the handle unit and the steering wheel and is capable of transmitting operations on the handle unit to the steering wheel, and the above-mentioned automatic control device, in which the steering coupling portion is detachable from the steering shaft. [Effects of the Invention]

[0008] According to one aspect of the present invention, an automatic control device is detachably attached to the steering shaft of an electric vehicle via a steering coupling. This not only enables the electric vehicle to be autonomous, but also enables an existing electric vehicle to be equipped with an autonomous driving function or an electric vehicle to malfunction, eliminating the need to transport the entire vehicle to a repair shop and allowing the vehicle itself to remain with the user, thereby avoiding situations where the user is inconvenienced by the absence of the vehicle. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a schematic diagram showing the overall configuration of an electric vehicle according to an embodiment of the present invention; [Figure 2] 3 is a schematic diagram showing a support structure for the automatic control unit according to the embodiment; FIG. [Figure 3]FIG. 2 is a schematic diagram showing a configuration of an automatic control unit according to the embodiment. [Figure 4] FIG. 2 is a schematic diagram illustrating a configuration of a control system according to the embodiment. [Figure 5] FIG. 10 is a schematic diagram showing a configuration of an automatic control unit mounted on an electric vehicle according to another embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0011] (Overall configuration of electric vehicle) Fig. 1 is a schematic diagram showing the configuration of a small electric vehicle V (hereinafter simply referred to as "electric vehicle") according to one embodiment of the present invention, as viewed from the left with respect to the forward direction of the electric vehicle V. In Fig. 1, left and right arrows L with respect to the plane of the paper indicate the front-to-rear direction of the electric vehicle V, and up and down arrows H indicate the up and down direction of the electric vehicle V. The left and right arrows L shown in Fig. 1, i.e., the front-to-rear direction, correspond to the traveling direction of the electric vehicle V when moving forward or backward, and the direction from right to left with respect to the plane of the paper corresponds to the forward direction of the electric vehicle V.

[0012] In this embodiment, the electric vehicle V can be used as a means of transportation for the elderly, the sick, and other people who have difficulty walking. The electric vehicle V is, for example, an electric wheelchair that can travel on sidewalks or a so-called senior car. In other words, the electric vehicle V is equipped with an electric motor as a driving source for traveling, and travels at a speed equal to or lower than the legally permitted upper speed limit for traveling on sidewalks. The maximum travel speed of the electric vehicle V when traveling is set to, for example, 6 km / h. The electric vehicle V can also be used to transport able-bodied people, including children.

[0013] The electric vehicle V is equipped with an automatic control unit U, and can be driven by a user or passenger manually operating the handle unit 31, and can also be steered automatically while driving by the automatic control unit U. In other words, the electric vehicle V has two driving modes set: a manual steering mode in which steering is performed manually via the handle unit 31, and an automatic steering mode in which steering is performed automatically by the automatic control unit U, and the actual driving mode while driving can be switched between these modes.

[0014] The manual steering mode and the automatic steering mode can be switched as desired by the user. The driving mode is switched using a mode selector switch 845 on the operation panel 311 built into the handle unit 31. The user can switch the driving mode by changing the position of the mode selector switch 845.

[0015] When traveling in manual steering mode, the force that the user applies to the handle unit 31 in the rotational direction (i.e., steering torque) is transmitted to the steered wheels (in this embodiment, the front wheels 11f) via the steering shaft 51. When moving the electric vehicle V forward, the user can turn the electric vehicle V clockwise by rotating the handle unit 31 clockwise, and can turn the electric vehicle V counterclockwise by rotating the handle unit 31 counterclockwise.

[0016] In contrast, when traveling in automatic steering mode, steering torque is transmitted to the front wheels 11f, which are steered wheels, from an electric motor (hereinafter sometimes referred to as "steering motor") ACT2 provided as a driving source for steering in the automatic control unit U. In other words, in the automatic operation mode, the torque used to change the direction of the steered wheels 11f is generated by the steering motor ACT2.

[0017] In automatic steering mode, the user can set a destination location and a route from the current location to the destination location. The destination location and route can be set by installing a touch panel display on the operation panel 311 that can be operated by the user, or by establishing communication with a mobile communication terminal owned by the user. An example of an applicable mobile communication terminal is a smartphone. The information necessary for route setting, such as the destination location, is obtained from the smartphone and the route is set.

[0018] The electric vehicle V travels automatically along a route set by the user, without the user's operation of the handle unit 31 (i.e., steering operation). At this time, the driver can control the acceleration, deceleration, and stopping of the electric vehicle V by operating the accelerator lever provided on the handle unit 31. The deceleration of the electric vehicle V is performed by the regenerative operation of the steering motor ACT2. A brake device that generates braking force on the front wheels 11f or the rear wheels 11r may be installed to decelerate the vehicle, or the brake device may be used to maintain the electric vehicle V in a stopped state after stopping until the next start. The operation of the brake device can be controlled in conjunction with the operation of the accelerator lever. For example, when starting off, the operation of the brake device is released in conjunction with the user's action of gripping the accelerator lever.

[0019] The basic configuration of the electric vehicle V will be described below, followed by a description of the automatic control unit U.

[0020] (Basic configuration) The electric vehicle V includes, as main components according to this embodiment, a chassis (not shown), wheels 11, a body cover 21, a handle unit 31, and a seat 41. In this embodiment, the electric vehicle V is a four-wheel vehicle, and includes a pair of left and right front wheels 11f and a pair of left and right rear wheels 11r.

[0021] The chassis is the undercarriage of the electric vehicle V, forms the skeletal structure of the electric vehicle V, and supports the various elements that make up the electric vehicle V. Specifically, the chassis supports drive system electrical components including the battery BAT and the driving actuator (hereinafter referred to as the "drive actuator") ACT1, and also supports the body cover 21, which will be described later.

[0022] The battery BAT is a secondary battery that can be charged and discharged, and the drive actuator ACT1 is an electric motor. The battery BAT serves as the power source for the drive actuator ACT1 and the steering actuator ACT2 (FIG. 2), which will be described later. The drive actuator ACT1 and the steering actuator ACT2 can be driven by receiving power from the battery BAT.

[0023] The front wheels 11f are provided on the left and right sides of the front portion of the electric vehicle V, and support the chassis via front suspension devices 12f against the road surface on which the electric vehicle V travels. In this embodiment, the front wheels 11f are steered wheels and driven wheels. The front wheels 11f are configured so that their rotation axes rotate around an axis perpendicular to the road surface and can be turned. The electric vehicle V can change its direction of travel depending on the orientation of the front wheels 11f.

[0024] The rear wheels 11r are provided on the left and right sides of the rear portion of the electric vehicle V, and support the chassis from the road surface via rear suspension devices 12r. In this embodiment, the rear wheels 11r are drive wheels, and their orientation is fixed. The left and right rear wheels 11r, 11r are connected to the electric vehicle V via wheel drive shafts that extend in the left-right direction perpendicular to the front-to-rear direction L. A drive actuator ACT1 is attached to the wheel drive shafts so as to be able to transmit its torque, and the rear wheels 11r are rotationally driven by the torque transmitted from the drive actuator ACT1 (hereinafter referred to as "drive torque"), thereby propelling the electric vehicle V.

[0025] Furthermore, a braking device (not shown) is provided to prevent the rotation of the rear wheel 11r. The braking device, for example, prevents the rotation of the rear wheel 11r by frictional force, decelerates the electric vehicle V through the frictional force acting on the rear wheel 11r, and can maintain the electric vehicle V in a stopped state after deceleration.

[0026] The vehicle body cover 21 is attached to the chassis so as to cover the entire chassis, encloses various elements supported by the chassis, and forms the exterior of the electric vehicle V. The vehicle body cover 21 has a cover main body 211, a front fender 212, and a rear fender 213.

[0027] The cover main body 211 is located near the center of the electric vehicle V in the front-rear direction L, and surrounds the battery BAT.

[0028] The front fender 212 is located at the front portion of the electric vehicle V and surrounds the front wheel 11f from above and behind.

[0029] The rear fender 213 extends rearward from the cover body 211 and surrounds the rear wheel 11r from above and in front. The front fender 212 and rear fender 213 prevent the front and rear wheels 11f, 11r from coming into contact with the outside, and also prevent a user seated on the seat 41 from getting mud splashed on them while riding.

[0030] The front fender 212 is provided with a night lighting device 22 that can illuminate the area ahead of the electric vehicle V, and the rear fender 213 is provided with a direction indicator 23.

[0031] The handle unit 31 is attached to the upper end of a steering shaft 51 that extends vertically, and is supported by the steering shaft 51.

[0032] The steering shaft 51 extends vertically between the left and right front wheels 11f, 11f, which are steered wheels, and connects each of the left and right front wheels 11f, 11f to the handle unit 31. In this embodiment, the steering shaft 51 is disposed obliquely and extends obliquely rearward from its lower end to its upper end. The lower end of the steering shaft 51 is connected to each of the left and right front wheels 11f, 11f via tie rods and knuckle arms (not shown).

[0033] That is, the handle unit 31 is mechanically connected to the front wheel 11f via the steering shaft 51. This allows the user to transmit the force (steering torque, hereinafter referred to as "steering torque") applied to the handle unit 31 to the front wheel 11f via the steering shaft 51 when traveling in manual steering mode.

[0034] The seat 41 is located above the cover body 211 and is supported on the chassis via a bracket (not shown). The seat 41 has a seating portion 411, a backrest 412, and an armrest 413, and is configured so that the user faces the forward direction of the electric vehicle V while sitting on the seating portion 411.

[0035] Backrest 412 is in an upright position from seating portion 411, and armrest 413 is attached to backrest 412 near its midpoint and extends forward from backrest 412. Armrest 413 can swing up and down around the connection with backrest 412, and can be switched between a standby state in which it is flipped up and a use state in which it is tilted down. In Fig. 1, armrest 413 in the use state is shown by a solid line, and armrest 413' in the standby state is shown by a two-dot chain line.

[0036] In the vehicle body cover 21, a floor step 214 is formed between the cover main body 211 and the front fender 212. The floor step 214 is located at the feet of a user seated on the seat 41. The seat 41 and the floor step 214 form the "living area" of the electric vehicle V.

[0037] In addition to the above, in this embodiment, a front basket 61 is provided in the front portion of the electric vehicle V as an element for storing or holding luggage to be transported by the electric vehicle V, i.e., as a luggage storage section. The front basket 61 is disposed above the front fender 212 and is formed integrally with the body cover 21. The front basket 61 is disposed in front of the living area or seat 41, specifically, in front of the steering shaft 51.

[0038] (Configuration of automatic control unit) Fig. 2 is a schematic diagram showing a support structure for the automatic control unit U according to this embodiment, and Fig. 3 is a schematic diagram showing the configuration of the automatic control unit U. The configuration of the automatic control unit U will be described using Fig. 2 while appropriately referring to Fig. 3.

[0039] The automatic control unit U includes a steering actuator ACT2, and is capable of transmitting torque generated by the steering actuator ACT2 (hereinafter referred to as "control torque" to distinguish it from the steering torque applied by the driver) to the front wheels 11f via the steering shaft 51. In other words, the automatic control unit U is capable of applying a torque to the front wheels 11f independently of or superimposed on the steering torque.

[0040] The automatic control unit U includes a steering coupling 71 and an automatic steering unit 81 (FIG. 1).

[0041] The steering connection part 71 is detachable from the steering shaft 51 and can transmit torque (e.g., steering torque) applied to the steering shaft 51 to the automatic steering unit 81, as well as transmit control torque from the automatic steering unit 81 to the steering shaft 51.

[0042] The automatic steering unit 81 is mounted to the steering shaft 51 via the steering coupling 71 so as to be capable of transmitting power. The automatic steering unit 81 includes a steering actuator ACT2, a first power transmission unit 801, a power connection / disconnection unit 802, a second power transmission unit 803, and a steering controller 804. Figure 3 shows the relative positions of the steering actuator ACT2, the first power transmission unit 801, the power connection / disconnection unit 802, and the second power transmission unit 803.

[0043] The steering actuator ACT2 constitutes a driving source for steering and generates a control torque. In this embodiment, the steering actuator ACT2 is an electric motor and can be driven by receiving power from a battery BAT. In other words, the steering actuator ACT2 shares a power source with the drive actuator ACT1.

[0044] The first power transmission unit 801 is interposed between the steering actuator ACT2 and the steering connector 71, and transmits the output of the steering actuator ACT2, that is, the control torque, to the steering shaft 51 via the steering connector 71.

[0045] As shown in FIG. 3, the first power transmission unit 801 has a gear train consisting of three gears 811, 812, and 813 with different numbers of teeth, and transmits control torque from the driving side to the driven side at a predetermined gear ratio R1.

[0046] Specifically, the first power transmission unit 801 has a first drive gear 811 arranged on the drive side closer to the power connection / disconnection unit 802, a first driven gear 812 arranged on the driven side closer to the steering coupling unit 71, and an intermediate gear 813 arranged between the first drive gear 811 and the first driven gear 812. The first drive gear 811 has N11 teeth, the first driven gear 812 has N12 teeth, and the intermediate gear 813 has N13 teeth. Here, the number of teeth N11 of the first drive gear 811 is smaller than the number of teeth N12 of the first driven gear 812, and the number of teeth N13 of the intermediate gear 813 is smaller than the number of teeth N11 and N12 of both the first drive gear 811 and the first driven gear 812.

[0047] The power connection / disconnection unit 802 is interposed between the steering actuator ACT2 and the first power transmission unit 801 so that the first power transmission unit 801 is on the driven side, and is capable of switching between transmitting and cutting off the control torque to the first power transmission unit 801. The power connection / disconnection unit 802 can be configured with an electromagnetic clutch. However, the power connection / disconnection unit 802 is not limited to this, and can also be configured with a clutch mechanism other than an electromagnetic type, such as a mechanical type or a hydraulic type.

[0048] The second power transmission unit 803 is interposed between the steering actuator ACT2 and the power connection / disconnection unit 802, and transmits the control torque generated by the steering actuator ACT2 to the first power transmission unit 801 via the power connection / disconnection unit 802.

[0049] As shown in FIG. 3, the second power transmission unit 803 has a gear train consisting of two gears 831 and 832 with different numbers of teeth, and transmits control torque from the driving side to the driven side at a predetermined gear ratio R2.

[0050] Specifically, the second power transmission unit 803 has a second drive gear 831 arranged on the drive side closer to the steering actuator ACT2, and a second driven gear 832 arranged on the driven side closer to the power connection / disconnection unit 802. The second drive gear 831 has N21 teeth, and the second driven gear 832 has N22 teeth. Here, the number of teeth N21 of the second drive gear 831 is smaller than the number of teeth N22 of the second driven gear 832.

[0051] In addition to the above, the automatic steering unit 81 is equipped with a steering controller 804 (FIG. 2). The steering controller 804 controls the operating state of the steering actuator ACT2 and also controls the operating state of the power connection / disconnection unit 802. The configuration of a control system including the steering controller 804 will be described in detail later.

[0052] (Automatic control unit support structure) Now, with reference to FIG. 2, the support structure of the automatic control unit U will be described.

[0053] In this embodiment, the automatic control unit U is supported on the chassis of the electric vehicle V by being attached to the steering shaft 51.

[0054] Specifically, of the components of the automatic control unit U described above, the steering coupling 71 and the first driven gear 812 of the first power transmission unit 801 are directly attached to the steering shaft 51 and are supported by the steering shaft 51, while the other components are supported on the steering shaft 51 via a frame unit F. The steering coupling 71 and the first driven gear 812 are integrally configured.

[0055] The steering coupling part 71 and the first driven gear 812 are configured to be attachable to the steering shaft 51, for example, by being divided into two parts, and when they are attached to the steering shaft 51, the separate parts are joined to each other in a state in which they sandwich the steering shaft 51. The steering coupling part 71 and the first driven gear 812 cannot rotate relative to the steering shaft 51, but rotate together with the steering shaft 51.

[0056] The frame unit F has a longitudinal extension member f1, a transverse extension member f2 (f21, f22, f23), and a film member f3.

[0057] The vertical extension member f1 is connected to the chassis of the electric vehicle V and extends in the vertical direction. In this embodiment, the vertical extension member f1 is attached to the steering shaft 51 by a bracket 851 and is connected to the chassis via the steering shaft 51. The bracket 851 is cylindrical, and the steering shaft 51 is rotatable inside the bracket 851. In other words, the vertical extension member f1 does not follow the rotation of the steering shaft 51 and can maintain its orientation even during steering. The vertical extension member f1 may be connected directly to the chassis without via the steering shaft 51.

[0058] The horizontal extension member f2 has multiple members, specifically, a first horizontal extension member f21, a second horizontal extension member f22, and a third horizontal extension member f23. The first, second, and third horizontal extension members f21, f22, and f23 all extend in a direction intersecting the vertical extension member f1 and support elements that make up the automatic steering unit 81.

[0059] The first horizontal extension member f21 extends from the middle portion of the vertical extension member f1 toward the front of the electric vehicle V and in a direction away from the steering shaft 51. The first horizontal extension member f21 has a flat plate shape and forms a first support surface that supports the steering actuator ACT2 from below.

[0060] The second horizontal extension member f22 extends parallel to the first horizontal extension member f21 from a portion above the middle portion of the vertical extension member f1, in this embodiment from the upper end or tip end of the vertical extension member f1 toward the front of the electric vehicle V. The second horizontal extension member f22 is also flat and forms a second support surface that supports the electromagnetic clutch of the power connection / disconnection unit 802 from below.

[0061] Thus, in this embodiment, the steering actuator ACT2 and the power disconnector 802 are placed on the first and second support surfaces formed by the first and second flat horizontal extension members f21 and f22, respectively, and are fixed to the first and second horizontal extension members f21 and f22.

[0062] In contrast, the first drive gear 811 and intermediate gear 813 constituting the first power transmission unit 801, and further the second drive gear 831 and second driven gear 832 constituting the second power transmission unit 803, can be supported appropriately by the first and second lateral extension members f21, f22. For example, by arranging each gear box accommodating the gears of the first and second power transmission units 801, 803 so as to span between the membrane member f3 described below, they are supported by the first and second lateral extension members f21, f22 via the membrane member f3.

[0063] The third horizontal extension member f23 extends parallel to the first horizontal extension member f21 from a portion below the middle portion of the vertical extension member f1, in this embodiment from the lower end or base end of the vertical extension member f1 toward the front of the electric vehicle V. The third horizontal extension member f23 is also flat and forms a third support surface that supports the steering controller 804 from below.

[0064] The membrane member f3 is connected to the laterally extending members f2 (f21, f22, f23) and surrounds each element of the automatic steering unit 81, namely, the steering actuator ACT2, the first drive gear 811, the intermediate gear 813, the power connection / disconnection unit 802 (electromagnetic clutch), the second drive gear 831, the second driven gear 832, and the steering controller 804 from three sides: the front, left, and right. The membrane member f3 divides the space surrounded by the outer surface of the front basket 61 into a storage section for the automatic steering unit 81 and a luggage storage section. Figure 1 schematically shows the storage section for the automatic steering unit 81 as an area indicated by a diagonally shaded, two-dot chain line.

[0065] In this embodiment, the frame unit F further includes a bearing 852 and a connecting member 853.

[0066] The bearing 852 is provided at a position separated from the steering coupling 71 in the axial direction of the steering shaft 51, and is attached to the outer periphery of the steering shaft 51. The bearing 852 is configured to be attachable to the steering shaft 51 by being divided into two parts, similar to the steering coupling 71 and the first driven gear 812.

[0067] The connecting member 853 connects the bearing 852 and the vertically extending member f1. In this embodiment, the connecting member 853 connects the bearing 852 and the tip end of the vertically extending member f1. As a result, the vertically extending member f1 is supported by the bracket 851 and the bearing 852 at two points, the base end and the tip end, of the steering shaft 51.

[0068] In this embodiment, the longitudinal extension member f1 corresponds to the "first frame member", and the transverse extension members f2 (f21, f22, f23) correspond to the "second frame member".

[0069] (Control system configuration) FIG. 4 is a schematic diagram showing the configuration of a control system according to this embodiment.

[0070] In the electric vehicle V, a power branching section 921 is provided midway along a power line (hereinafter referred to as the "traveling power supply line") 911 that supplies power from a battery BAT to a drive actuator ACT1, and a power line (hereinafter referred to as the "branching power supply line") 912 is provided that extends from the power branching section 921 in parallel with the traveling power supply line 911.

[0071] A motor drive circuit 931 is connected to one end of the traveling power supply line 911, and the power supplied from the battery BAT through the traveling power supply line 911 is converted by the motor drive circuit 931 into three-phase motor drive power and supplied to the electric motor, which is the drive actuator ACT1.

[0072] On the other hand, a connection part 922 is provided at one end of the branch feeder 912, and a power line (hereinafter referred to as "steering feeder") 913 leading to the steering actuator ACT2 is detachably connected to the connection part 922. By connecting the steering feeder 913 to the connection part 922, the branch feeder 912 and the steering feeder 913 are conducted to each other, and power from the battery BAT can be supplied to the steering actuator ACT2 via the steering feeder 913.

[0073] A motor drive circuit 932 is connected to one end of the steering power supply line 913, and the power supplied from the battery BAT through the branch power supply line 912 and the steering power supply line 913 is converted by the motor drive circuit 932 into three-phase motor drive power and supplied to the electric motor which is the steering actuator ACT2.

[0074] The control system includes a steering controller 804 , a laser sensor 841 , a camera sensor 842 , a steering angle sensor 843 , a system activation switch 844 and a mode changeover switch 845 .

[0075] The steering controller 804 constitutes the calculation section of the control system. In this embodiment, the steering controller 804 is constituted by a microcomputer equipped with a central processing unit (CPU), an input / output interface, and storage units such as ROM and RAM. The steering controller 804 receives output signals from various sensors 841 to 843 and switches 844 and 845 as inputs. It then executes predetermined calculations and generates command signals according to the results of the calculations, which are output to the steering actuator ACT2 (specifically, the motor drive circuit 932) and the power connection / disconnection section 802.

[0076] The laser sensor 841 is disposed so as to be able to irradiate an electromagnetic wave (for example, a laser) with a relatively short wavelength to an area around the vehicle including the front of the electric vehicle V. As the laser sensor 841, a LiDAR can be applied.

[0077] The camera sensor 842 is installed so that the field of view covers the area in front of the electric vehicle V. As the camera sensor 842, a monocular camera or a stereo camera can be used.

[0078] The laser sensor 841 and the camera sensor 842 both correspond to external sensors and monitor the conditions around the electric vehicle V. The laser sensor 841 and the camera sensor 842 can be installed on a frame unit F and supported by the frame unit F. For example, as shown in FIG. 2, the laser sensor 841 is installed on a plate-like member attached to the membrane member f3 so as to cover the upper end opening thereof, and the camera sensor 842 is installed on the second horizontal extension member f22. Here, the plate-like member supporting the laser sensor 841 constitutes a "support member" for installing the laser sensor, and the second horizontal extension member f22 supporting the camera sensor 842 also serves as a "support member" for installing the camera sensor.

[0079] The steering angle sensor 843 detects the steering angle of the electric vehicle V, in other words, the angle that the front wheels 11f make with respect to their positions when traveling straight ahead. In this embodiment, the steering angle sensor 843 is disposed so as to be able to detect the rotation angle of the first drive gear 811, and detects the steering angle of the electric vehicle V by converting the rotation angle of the first drive gear 811 into the steering angle of the steering shaft 51. The steering angle sensor 843 can be installed by attaching it to the gearboxes of the first drive gear 811 and the intermediate gear 813, or by supporting it on the membrane member f3 using an appropriate bracket.

[0080] The system activation switch 844 switches the power supply to the steering controller 804 on and off.

[0081] The mode changeover switch 845 changes the driving mode of the electric vehicle V between a manual steering mode and an automatic steering mode.

[0082] In this embodiment, the mode changeover switch 844 and the system activation switch 845 are provided on the operation panel 311 and can both be manually operated by a user seated on the seat 41 .

[0083] In addition to the above, in this embodiment, an emergency stop button 941 is provided. The emergency stop button 941 may be installed in either the front or rear part of the body of the electric vehicle V, or may be installed in both the front and rear parts. For example, the emergency stop button 941 is installed in the handle unit 31 and the upper end part of the backrest 412, respectively.

[0084] The emergency stop button 941 can be operated in an emergency by a user on board the electric vehicle V or a third party around the electric vehicle V, and forcibly cuts off the flow of current in the traveling power feeder 911 and the steering power feeder 912. This allows the user or third party to stop the operation of the drive actuator ACT1 and the steering actuator ACT2 and immediately stop the electric vehicle V.

[0085] (Explanation of action and effect) The electric vehicle V according to this embodiment has the above-described configuration. The effects obtained by this embodiment will be described below.

[0086] First, the automatic control unit U is configured to include a steering connection part 71 and an automatic steering unit 81, and the steering connection part 71 is detachable from the steering shaft 51 of the electric vehicle V, and the automatic steering unit 81 is attached so that power can be transmitted via the steering connection part 71, making it easy to realize automatic driving of the electric vehicle V.

[0087] For example, if a user who owns an electric vehicle V that is exclusively for manual driving, such as an electric wheelchair, wishes to use an electric vehicle V with an automatic driving function, this can be achieved by converting the electric vehicle V that the user owns into an automatic driving vehicle with minimal modification work, without having to repurchase or acquire a new electric vehicle with an automatic driving function.

[0088] Users will then be able to use the newly equipped automatic control system in addition to the familiar manual operation system.

[0089] Furthermore, not only will it be possible to realize autonomous driving of electric vehicles V, but it will also be possible to improve convenience from the following perspectives:

[0090] When equipping an existing electric vehicle V with an autonomous driving function, there is no need to transport the entire vehicle to a repair shop, and the vehicle itself can be left with the user. By manually driving the electric vehicle V, the user can ensure transportation until the installation is complete.

[0091] On the other hand, if a malfunction occurs in the electric vehicle V, the problem can be resolved by transporting only the automatic control unit U or the automatic steering unit 81 to the factory, so that the vehicle itself can be left with the user, and it is possible to avoid a situation in which the user is inconvenienced by the absence of the electric vehicle V.

[0092] Secondly, by interposing a power connection / disconnection unit 802 between the steering actuator ACT2 and the first power transmission unit 801 and making it possible to cut off the transmission of power from the steering actuator ACT2 to the first power transmission unit 801, it is possible to avoid a situation in which the electric motor, which is the steering actuator ACT2, becomes a load on the handle unit 31 when driving manually, thereby ensuring light operability.

[0093] Furthermore, by adjusting or appropriately controlling the fastening force of the power disconnecting unit 802, if the vehicle is steered in a direction different from the user's intention or prediction while driving in automatic steering mode, the user can operate the handle unit 31 to direct the electric vehicle V in a direction that is in line with the user's intention or prediction, in other words, to correct the direction of travel of the electric vehicle V.

[0094] Such an operation can be easily achieved by causing slippage or disengagement of the power disconnecting part 802 when the torque (i.e., steering torque) applied by the user to the steering shaft 51 via the handle unit 31 exceeds the torque (i.e., control torque) applied by the automatic steering unit 81 to the steering shaft 51 via the steering coupling part 71, thereby transmitting the steering torque to the steered wheel 11f in priority to the control torque.

[0095] Thirdly, by interposing the second power transmission unit 803 between the steering actuator ACT2 and the power disconnection unit 802, the output of the steering actuator ACT2 (i.e., the control torque) can be transmitted to the first power transmission unit 801 at a predetermined reduction ratio R1, making it possible to apply the required steering torque to the steering shaft 51 while using a relatively small electric motor for the steering actuator ACT2.

[0096] Fourth, by extending the steering shaft 51 downward from the handle unit 31 and positioning the steering actuator ACT2 lower than the steering connection part 71, the center of gravity of the entire automatic steering unit 81 is lowered, making it possible to suppress instability of the vehicle body due to the installation or addition of the automatic control unit U.

[0097] Fifth, by positioning the automatic steering unit 81 further forward in the fore-and-aft direction of the electric vehicle V than the steering connection portion 71, it is possible to avoid a situation in which the livability of the vehicle is impaired due to interference with the automatic steering unit 81.

[0098] Sixth, the frame unit F makes it possible to firmly support the automatic steering unit 81 including the steering actuator ACT2, which is a heavy object, on the chassis of the electric vehicle V.

[0099] Here, the frame unit F is connected to the chassis and is configured to include a vertical extension member f1 extending in the vertical direction, and a horizontal extension member f2 (f21, f22, f23) extending in a direction intersecting the vertical extension member f1, and by supporting the steering actuator ACT2 by the first horizontal extension member f21, it is possible to avoid a situation in which the position of the steering actuator ACT2 is affected when operating the steering shaft 51.

[0100] Seventh, by installing a bearing 852 at a position away from the steering connecting portion 71 in the axial direction of the steering shaft 51 and connecting the bearing 852 to the vertical extension member f1 with a connecting member 853, it is possible to prevent the vertical extension member f1 from being cantilevered relative to the chassis and to more firmly support the entire automatic steering unit 81 including the steering actuator ACT2.

[0101] Eighth, the external sensors 841, 842 make it possible to monitor the surrounding conditions, and by supporting them with the support members of the frame unit F, it is possible to integrate elements related to automatic control, including the automatic steering unit 81 and the external sensors 841, 842, and reduce the space required to install the automatic control unit U.

[0102] (Description of Other Embodiments) FIG. 5 is a schematic diagram showing the configuration of an automatic control unit U mounted on a small electric vehicle V according to another embodiment of the present invention.

[0103] In this embodiment, the second power transmission unit 803' is provided with self-constraint properties. The self-constraint properties can be provided by, for example, a worm gear 831' and a worm wheel 832'. Specifically, the worm gear 831' is used as the second drive gear of the second power transmission unit 803', and the worm wheel 832' is used as the second driven gear.

[0104] In this way, by providing the second power transmission unit 803' with self-restraint properties, it is possible to suppress a situation in which, when traveling in automatic steering mode, the direction of the steered wheels 11f changes due to the torque transmitted from the handle unit 31, that is, the torque applied by the user to the steering shaft 51 via the handle unit 31. In other words, when traveling in automatic steering mode, it is possible to avoid the steering by the automatic steering unit 81 being hindered by unnecessary handle operation by the user.

[0105] Furthermore, by applying a worm gear 831' and a worm wheel 832' to the second power transmission section 803', it is possible to ensure a high reduction ratio in the second power transmission section 803' while reducing the size of the automatic steering unit 81, and to suppress the generation of vibrations and noise from the automatic steering unit 81.

[0106] Traveling in the automatic mode is not limited to steering, but can also be performed for accelerating and decelerating the electric vehicle V. The starting point and the destination point are set in advance, and the electric vehicle V travels automatically along a predetermined route from the starting point to the destination point. In this case, the operation of the drive actuator ACT1 is controlled by a drive controller provided separately from the steering controller 804. This makes it possible to run the electric vehicle V not only when a user is seated in the seat 41, but also when the seat 41 is vacant, i.e., when unmanned, and to collect or dispatch the electric vehicle V unmanned.

[0107] Furthermore, the steering coupling part 71 can be configured not only to be detachable from the steering shaft 51, but also to be switchable between a fastened state in which torque is transmitted between the steering shaft 51 and the automatic steering unit 81, and a disconnected state in which torque transmission is disconnected. This makes it possible to integrate the function of the power disconnecting part 802 into the steering coupling part 71 and further simplify the configuration. [Explanation of symbols]

[0108] V...electric vehicle, U...automatic control unit, F...frame unit, 11f...front wheel, 11r...rear wheel, 12f...front suspension device, 12r...rear suspension device, 21...body cover 21, 211...cover main body, 212...front fender, 213...rear fender, 31...handle unit, 41...seat, 51...steering shaft, 61...front basket, 71...steering coupling portion, 81...automatic steering unit, 801...first power transmission portion, 802...power disconnection portion, 803, 803' ...Second power transmission unit, 804...Steering controller, 841...Laser sensor (external sensor), 842...Camera sensor (external sensor), 843...Steering angle sensor, 844...System start switch, 845...Mode switching switch, 941...Emergency stop button, f1...Vertical extension member (first frame member), f2...Horizontal extension member (second frame member), f21...First horizontal extension member, f22...Second horizontal extension member, f23...Third horizontal extension member, f3...Membrane member, ACT1...Drive actuator, ACT2...Steering actuator.

Claims

1. An automatic control device for an electric vehicle having a manually operable handle unit, a steering wheel, and a steering shaft that connects the handle unit and the steering wheel and is capable of transmitting an operation of the handle unit to the steering wheel, a steering coupling portion detachable from the steering shaft; an automatic steering unit attached to the steering shaft via the steering coupling portion so as to be capable of transmitting power, The automatic steering unit an electric motor that is a power source for steering; a first power transmission unit that transmits an output torque of the electric motor to the steering connecting unit; and a steering controller that controls the operating state of the electric motor.

2. the automatic steering unit further includes a power disconnection unit interposed between the electric motor and the first power transmission unit and capable of interrupting transmission of the output torque to the first power transmission unit, The automatic control device for an electric vehicle according to claim 1 , wherein the steering controller is capable of controlling an operating state of the power connection / disconnection unit.

3. 3. The automatic control device for an electric vehicle according to claim 2, further comprising a second power transmission unit interposed between the electric motor and the power connection / disconnection unit, for transmitting an output torque of the electric motor to the first power transmission unit at a predetermined reduction ratio.

4. The automatic control device for an electric vehicle according to claim 3 , wherein the second power transmission unit has a self-restraining property.

5. The steering shaft extends downward from the handle unit, The automatic control device for an electric vehicle according to claim 1 , wherein the electric motor is disposed at a lower position than the steering coupling portion.

6. The automatic control device for an electric vehicle according to claim 1 , wherein the automatic steering unit is disposed forward of the steering coupling in the longitudinal direction of the electric vehicle.

7. a frame unit for supporting the automatic steering unit on a vehicle body of the electric vehicle; The frame unit includes: a first frame member coupled to the vehicle body and extending in the vertical direction; The automatic control device for an electric vehicle according to claim 1 , further comprising: a second frame member extending in a direction intersecting the first frame and supporting the electric motor.

8. The frame unit includes: a bearing provided at a position spaced apart from the steering coupling portion in the axial direction of the steering shaft and attached to an outer periphery of the steering shaft; The automatic control device for an electric vehicle according to claim 7 , further comprising: a connecting member that connects the bearing and the first frame member.

9. An external sensor for monitoring a situation around the electric vehicle is further provided, The frame unit includes: Further provided is a support member extending in a direction intersecting the first frame member, The automatic control device for an electric vehicle according to claim 7 , wherein the external sensor is supported by the support member.

10. a handle unit that can be manually operated by a passenger; The steering wheel and a steering shaft that connects the handle unit and the steering wheel and is capable of transmitting an operation of the handle unit to the steering wheel; An electric vehicle comprising: the automatic control device according to any one of claims 1 to 9, wherein the steering coupling portion is detachable from the steering shaft.

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