Patent Publication Number: US-2020283091-A1

Title: Vehicle

Description:
TECHNICAL FIELD 
     The present invention relates to a vehicle that performs position control in accordance with a travel condition such as turning or a change in a road surface and can be propelled by an activating force of a driver. 
     BACKGROUND ART 
     A vehicle that can be propelled by rotating a wheel by an activating force of a driver such as a cycle which has three or more wheels and in which at least one of a front wheel section and a rear wheel section is configured from a left/right pair of wheels (hereinafter, a vehicle whose front wheel section is configured from a pair of wheels will be referred to as “front two-wheeled type vehicle, and a vehicle whose rear wheel section is configured from a pair of wheels will be referred to as “rear two-wheeled type vehicle”) is usually stable against an inclination or unsteadiness because of multiple wheels of three or more wheels compared to a bicycle with two wheels in related art in which one wheel is arranged in each of the front wheel section and the rear wheel section. However, because it is difficult to turn a handle due to heavy steering of the handle, the vehicle is likely to be off the course to be traveled in turning in a curve or the like and in traveling on an inclined road surface, a bumpy road surface, or the like. Particularly, because a vehicle whose left/right pair of wheels are fixed may not control the balance of the center of gravity by performing appropriate position control, such a vehicle is abruptly inclined due to sudden turning or sudden braking or an impact from the road surface, and the position of the vehicle is likely to become unstable. 
     In relation to such a problem, Patent Literature 1 discloses a front two-wheeled type vehicle with three wheels in which a whole link mechanism moves to the left or right in response to the steering of the handle and discloses that the link movability state of the link mechanism is adjusted by using a link angle control device, the link angle control device is attached to a holding section attached to a stem section and a link mechanism section, the link angle control device is set, in a low velocity range, to have a tendency in which the movability state of the link is fixed and, in intermediate and high velocity ranges, to have a tendency in which a movability resistance of the link is removed, in accordance with the opening of an electrical (electromagnetic) servo valve that is controlled from a vehicle body velocity sensor of the wheels via an ECU, the movability state of the link angle of the link mechanism is controlled, and the position of the vehicle body is thereby controlled. 
     CITATION LIST 
     Patent Literature 
     PATENT LITERATURE 1: JP-A-2010-184508 
     SUMMARY OF INVENTION 
     Technical Problem 
     A front two-wheeled type vehicle with three wheels, in which a right wheel and a left wheel in a front wheel section have the same rotational forces as in Patent Literature 1, can improve stability against a positional change in turning in a curve. However, there is a problem that in front two-wheeled type or rear two-wheeled type vehicles that include the front two-wheeled type vehicle with three wheels as in Patent Literature 1, steerability of a handle in a case of turning at a high velocity, positional stability of the vehicle in a case of sudden turning, followability of vehicle control in a case where the center of gravity of the vehicle rapidly changes, and alleviation against inclination of the vehicle are not sufficient. 
     Accordingly, one object of the present invention is to provide a vehicle which includes a pair of motors which respectively control rotational forces of a left/right pair of wheels in at least one of a front wheel section and a rear wheel section independently of one another, performs position control, in accordance with a travel condition such as turning or a change in a road surface, by further attaching the pair of wheels via a suspension mechanism, secures stability against a position change, and can be propelled by rotating a wheel by an activating force of a driver. 
     Solution to Problem 
     One aspect of the present invention provides a vehicle in which at least one of a front wheel section and a rear wheel section is configured from a left/right pair of wheels and which is capable of being propelled by an activating force of a driver, in which a condition of the vehicle is detected, a rotational force of each of the pair of wheels is capable of being controlled independently of one another in response to the detection, and the pair of wheels are attached to the vehicle via a suspension mechanism. 
     According to one specific example of the present invention, in the vehicle, the pair of wheels are capable of being inclined with respect to the vehicle by the suspension mechanism. 
     According to one specific example of the present invention, in the vehicle, the pair of wheels are capable of operating, independently of one another, with respect to a height direction of the vehicle by the suspension mechanism. 
     According to one specific example of the present invention, the vehicle includes: a battery; a pair of motors that are connected with the battery and are configured from a motor for controlling a rotational force of one of the pair of wheels and a motor for controlling a rotational force of the other of the pair of wheels; a sensor that detects the condition and transmits a condition signal based on the detection; a vehicle body controller that performs arithmetic processing of the condition signal and transmits a control signal for controlling the pair of motors; and a motor driver that controls power supply between the battery and the pair of motors based on the control signal transmitted from the vehicle body controller, in which the motor driver controls each of outputs of the pair of motors independently of one another to be capable of controlling each of the rotational forces of the pair of wheels independently of one another. 
     According to one specific example of the present invention, in the vehicle, the sensor includes an inclination sensor that detects an inclination of the vehicle with respect to a perpendicular direction, and the vehicle body controller is capable of performing arithmetic processing of the condition signal transmitted from the sensor so as to correct the condition and of transmitting the control signal. 
     According to one specific example of the present invention, in the vehicle, the sensor further includes an activating force sensor that detects the activating force by the driver of the vehicle, and the vehicle body controller is capable of performing arithmetic processing of the condition signal transmitted from the sensor so as to correct the condition and of transmitting the control signal. 
     According to one specific example of the present invention, in the vehicle, the sensor further includes a velocity sensor that detects a velocity of the vehicle, and the vehicle body controller is capable of performing arithmetic processing of the condition signal transmitted from the sensor so as to correct the condition and of transmitting the control signal. 
     According to one specific example of the present invention, in the vehicle, at least one of the pair of motors has a function of a generator, and the at least one of the pair of motors is capable of providing a reverse rotational torque to the wheel and of supplying power to the battery via the motor driver by recovering travel energy of the vehicle by the function of the generator. 
     Advantageous Effects of Invention 
     According to the present invention, motors are respectively arranged on a pair of wheels, outputs of the pair of motors are controlled independently of one another, rotational forces of the pair of wheels are controlled independently of one another, further the pair of wheels are attached via a suspension mechanism, an inclination of the vehicle due to turning, a change in a road surface, and the like is thereby corrected, and position control corresponding to a travel condition can thereby be performed while unsteadiness is reduced. Further, a condition of the vehicle is detected by a sensor, arithmetic processing is performed based on a detection result thereof, and the rotational forces that are optimal for the pair of wheels and are independent of one another can thereby be generated. In addition, in a case where the position control is performed, the motor is activated as a generator to recover travel energy of the vehicle, and power may be supplied to a battery. Further, because the outputs of the pair of motors can be controlled independently of one another, while one of the motors supplies power from the battery to the motor to provide a forward rotational torque to the wheel, the other of the motors can be activated as a generator to provide a reverse rotational torque to the wheel, and power can be supplied from the motor to the battery. 
     Other objects, features, and advantages of the present invention will become apparent from the following descriptions of the embodiments of the present invention taken in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a schematic diagram of a vehicle as one embodiment of the present invention as seen from a side. 
         FIG. 2A  is a schematic diagram of the vehicle of  FIG. 1  as seen from a front side. 
         FIG. 2B  is a schematic diagram of the vehicle of  FIG. 1  as seen from the front side in a case where the vehicle is inclined to the left when seen from a driver. 
         FIG. 2C  is a schematic diagram of a vehicle as another embodiment of the present invention as seen from the front side. 
         FIG. 2D  is a schematic diagram of the vehicle of  FIG. 2C  as seen from the front side in a case where a road surface has a bump. 
         FIG. 2E  is a schematic diagram of the vehicle of  FIG. 2C  as seen from the front side in a case where the road surface is inclined. 
         FIG. 2F  is a schematic diagram of the vehicle of  FIG. 2C  as seen from the front side in a case where the vehicle is inclined to the left when seen from the driver. 
         FIG. 2G  is a perspective diagram that illustrates the relationship between a suspension mechanism and motors in the vehicle of  FIG. 2C . 
         FIG. 3  is a diagram that illustrates a condition in which motors in a control device used in the vehicle as the embodiment of the present invention are activated as electric motors. 
         FIG. 4  is a diagram that illustrates a condition in which the motors in the control device used in the vehicle as the embodiment of the present invention are activated as the generators. 
         FIG. 5  is a diagram that illustrates a flowchart of a method for controlling the vehicle as the embodiment of the present invention. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Embodiments of the present invention will hereinafter be described with reference to drawings, but the present invention is not limited to those embodiments. 
       FIG. 1 ,  FIG. 2A , and  FIG. 2B  illustrate a vehicle  100  as one embodiment of the present invention. A vehicle herein is a vehicle in which at least one of a front wheel section and a rear wheel section is configured from a left/right pair of wheels and which can be propelled by rotating a wheel in at least one of the front wheel section and the rear wheel section by an activating force of a driver of the vehicle. As such a vehicle, for example, there is a cycle that can be propelled by rotating a wheel by an effort, as the activating force, provided to pedals by the driver. In the following embodiments, a description will be made particularly about a cycle among vehicles, but the present invention may be employed for vehicles which can be propelled by the activating force of the driver other than a cycle. The vehicle  100  is a front two-wheeled type tricycle in which a front wheel section of the front wheel section and a rear wheel section is configured from a left/right pair of wheels and includes the left/right pair of wheels that are arranged in the front wheel section and have a first wheel  101  positioned on the right side when seen from the driver and a second wheel  102  positioned on the left side when seen from the driver and a third wheel  103  arranged in the rear wheel section. In this case, one or more wheels may be included in the rear wheel section. 
     The vehicle  100  includes a battery  109  and a pair of motors configured from a first motor  104  that is arranged on a hub of the first wheel  101  and for controlling the rotational force of the first wheel  101  and a second motor  105  that is arranged on a hub of the second wheel  102  and for controlling the rotational force of the second wheel  102 . The pair of motors  104  and  105  are connected with the battery  109 . Note that the vehicle  100  of  FIG. 1 ,  FIG. 2A , and  FIG. 2B  is a front two-wheeled type tricycle with three wheels whose front wheel section is configured from the left/right pair of wheels but may be a rear two-wheeled type vehicle whose rear wheel section is configured from a left/right pair of wheels. Among rear two-wheeled type vehicles, for example, in a case of a rear two-wheeled type cycle, a rotation difference may be provided to left and right wheels by employing differential gears in the rear wheels, and further a motor is arranged on a hub of each of the left and right wheels. 
     The vehicle  100  includes a suspension mechanism  113 , and the first wheel  101  and the second wheel  102  are attached to the vehicle  100  via the suspension mechanism  113 . The suspension mechanism  113  of the vehicle  100  of  FIG. 2A  and  FIG. 2B  is a link mechanism. As illustrated in  FIG. 2A , the suspension mechanism  113  is in a substantially rectangular shape in a case where the vehicle  100  is not inclined with respect to the perpendicular direction. However, as illustrated in  FIG. 2B , the suspension mechanism  113  is immediately inclined into a substantially parallelogram shape in accordance with the angle of inclination in a case where the vehicle  100  is inclined with respect to the perpendicular direction. The suspension mechanism  113  is inclined, and the first wheel  101  and the second wheel  102  attached to the vehicle  100  via the suspension mechanism  113  can be inclined with respect to the vehicle  100  at the same angle as the inclination of the suspension mechanism  113 , that is, the inclination of the vehicle  100  with respect to the perpendicular direction. That is, the respective positions of the first wheel  101  and the second wheel  102  with respect to the height direction of the vehicle  100  can be differentiated so as to conform with the inclination of the vehicle  100  with respect to the perpendicular direction. Thus, even in a case where the vehicle  100  is inclined with respect to the perpendicular direction, the first wheel  101  and the second wheel  102  can be grounded to a road surface, and the position of the vehicle  100  is stabilized with high mechanical conformity. Note that even in a case where the road surface on which the vehicle  100  is traveling is inclined or a case where a bump is present, the suspension mechanism  113  is immediately inclined into a substantially parallelogram shape similarly, and the first wheel  101  and the second wheel  102  can be inclined with respect to the vehicle  100  at the same angle as the inclination of the suspension mechanism  113 . Thus, even in a case where the road surface on which the vehicle  100  is traveling is inclined or a case where a bump is present, the first wheel  101  and the second wheel  102  can be grounded to the road surface, and the position of the vehicle  100  is stabilized with high mechanical conformity. 
       FIG. 2C  to  FIG. 2F  illustrate the vehicle  100  as another embodiment of the present invention, and the relationship between the suspension mechanism  113  and the first motor  104  and second motor  105  of the vehicle  100  as the other embodiment is illustrated in  FIG. 2G . The vehicle  100  as the other embodiment of the present invention in  FIG. 2C  to  FIG. 2F  is different only in the suspension mechanism  113  compared to the vehicle  100  as the one embodiment of the present invention in  FIG. 2A  and  FIG. 2B . As illustrated in  FIG. 2G , the suspension mechanism  113  includes a suspension shaft  122 , the first motor  104  arranged on the hub of the first wheel  101 , the second motor  105  arranged on the hub of the second wheel  102 , a first arm  123  for connecting the suspension shaft  122  and the first motor  104  together, and a second arm  124  for connecting the suspension shaft  122  and the second motor  105  together. The first arm  123  and the second arm  124  are attached to the suspension shaft  122  so as to be, independently of one another, rotatable with respect to the suspension shaft  122  as indicated by the arrows. The first motor  104  and the second motor  105  operate, independently of one another, with respect to the height direction of the vehicle  100  by rotations of the first arm  123  and the second arm  124 , and in accordance with that, the first wheel  101  and the second wheel  102  also operate, independently of one another, with respect to the height direction of the vehicle  100 . As illustrated in  FIG. 2C , in a case where the vehicle  100  travels on a horizontal road surface, the first arm  123  and the second arm  124  are parallel with each other. However, as illustrated in  FIG. 2D , in a case where the vehicle  100  travels on a road surface on which a bump is present, one arm (the second arm  124  in  FIG. 2D ) immediately rotates, and the motor and wheel connected with the arm (the second motor  105  and the second wheel  102  in  FIG. 2D ) can operate upward. Thus, the first wheel  101  and the second wheel  102  are together grounded to the road surface, and the position of the vehicle  100  is stabilized with high mechanical conformity. As illustrated in  FIG. 2E , in a case where the vehicle  100  travels on an inclined road surface, the first arm  123  and the second arm  124  immediately and respectively rotate to opposite directions, and the motors and wheels connected with the respective arms can operate upward and downward (in  FIG. 2E , the first motor  104  and the first wheel  101  operate downward, and the second motor  105  and the second wheel  102  operate upward). Thus, the first wheel  101  and the second wheel  102  are together grounded to the road surface, and the position of the vehicle  100  is stabilized with high mechanical conformity. As illustrated in  FIG. 2F , in a case where the vehicle  100  is inclined with respect to the perpendicular direction, the first arm  123  and the second arm  124  immediately and respectively rotate to opposite directions, and the motors and wheels connected with the respective arms can operate upward and downward (in  FIG. 2F , the first motor  104  and the first wheel  101  operate downward, and the second motor  105  and the second wheel  102  operate upward). Thus, the first wheel  101  and the second wheel  102  are together grounded to the road surface, and the position of the vehicle  100  is stabilized with high mechanical conformity. 
     Further, the suspension mechanism  113  as in  FIG. 2C  to  FIG. 2G  is employed for the link mechanism as the suspension mechanism  113  in  FIG. 2A  and  FIG. 2B , the first arm  123  and the second arm  124  are connected with the link mechanism, and the first motor  104  and the second motor  105  may respectively be connected with the link mechanism via the first arm  123  and the second arm  124 . The first arm  123  and the second arm  124  are attached to the link mechanism so as to be, independently of one another, rotatable with respect to the link mechanism, the first motor  104  and the second motor  105  operate, independently of one another, with respect to the height direction of the vehicle  100  by rotations of the first arm  123  and the second arm  124 , and in accordance with that, the first wheel  101  and the second wheel  102  can thereby also operate, independently of one another, with respect to the height direction of the vehicle  100 . 
     Further, the vehicle  100  includes a sensor group that detect conditions of the vehicle  100  and transmit condition signals based on the detection. As illustrated in  FIG. 1 , as the conditions of the vehicle  100  may include the inclination of the vehicle  100  with respect to the perpendicular direction, the activating force of the driver of the vehicle  100 , and the velocity of the vehicle  100 , for example, and those are respectively detected by an inclination sensor  106 , an activating force sensor  107 , a velocity sensor  108 , and the like. 
       FIG. 3  and  FIG. 4  illustrate a control device  117  that is used for the vehicle  100  in which at least one of the front wheel section and the rear wheel section is configured from a left/right pair of wheels which have a right wheel as the first wheel  101  and a left wheel as the second wheel  102 . The control device  117  includes the battery  109 , the pair of motors that are connected with the battery  109  and configured from the first motor  104  which controls the rotational force of the right wheel as the first wheel  101  and the second motor  105  which controls the rotational force of the left wheel as the second wheel  102 , the sensor group that includes the inclination sensor  106 , the activating force sensor  107 , and the velocity sensor  108 , detects the conditions of the vehicle  100 , and transmits condition signals based on the detection (inclination signal  118 , activating force signal  119 , and velocity signal  120 ), a vehicle body controller  114  that receives the condition signals  118  to  120 , performs arithmetic processing, and transmits a control signal  121  for controlling outputs of the first motor  104  and the second motor  105 , and a first motor driver  115  that controls power supply between the battery  109  and the first motor  104  and a second motor driver  116  that controls power supply between the battery  109  and the second motor  105  based on the control signal  121  transmitted from the vehicle body controller  114 . In such a manner, the first motor driver  115  and the second motor driver  116  that receive the control signal  121  respectively supply power from the battery  109  to the first motor  104  and the second motor  105  at a certain timing, supply power from the first motor  104  and the second motor  105  to the battery  109  at a certain timing, and can control the output of the first motor  104  and the output of the second motor  105  independently of one another. 
     Note that the first motor driver  115  and the second motor driver  116  may be an integrated motor driver. In addition, the vehicle body controller  114 , the first motor driver  115 , and the second motor driver  116  may be an integrated controller. Further, the vehicle body controller  114 , the first motor driver  115 , and the second motor driver  116  may be arranged on a handle  112  as a section gripped by the driver of the vehicle  100  or may be arranged below a saddle  111  in a case where the vehicle  100  is a cycle. In  FIG. 3  and  FIG. 4 , the control signal  121  is transmitted from the vehicle body controller  114  to each of the first motor driver  115  and the second motor driver  116  by one signal line. However, the control signal  121  is caused to have respective authentication codes for the first motor driver  115  and the second motor driver  116 , and transmission may thereby be performed by a single signal line and may further be performed in a wired manner or a wireless manner. 
     The inclination sensor  106  of the sensor group is activated by power from the battery  109  and detects the inclination of the vehicle  100  with respect to the perpendicular direction (the height direction of the vehicle  100 ). Inclusion of the inclination sensor  106  enables detection of unsteadiness in which the vehicle  100  is inclined alternately to the left and right due to turning of the vehicle, a change in a road surface, and the like. As the inclination sensor  106 , for example, an inclination angle sensor and a gyro sensor are present. As illustrated in  FIG. 1 , in a case where the vehicle  100  is a cycle, the inclination sensor, the gyro sensor, or the like may be arranged below the saddle  111 . As illustrated in  FIG. 2B , in a case where the vehicle  100  is inclined to the left with respect to the perpendicular direction when seen from the driver, an inclination angle θ is detected by the inclination sensor, or an angular velocity with respect to the inclination angle θ is detected by the gyro sensor, and the inclination of the vehicle  100  is thereby detected. Further, as the inclination sensor  106 , for example, a torque sensor is present. The torque sensor is arranged on each of the first wheel  101  and the second wheel  102 , and the inclination of the vehicle  100  can be detected by using the difference between the respective torques of the wheels detected by the torque sensors. Further, as the inclination sensor  106 , for example, a steering angle sensor is present. The steering angle sensor is arranged on the handle  112  as the section gripped by the driver, and the inclination of the vehicle  100  can be detected by using the steering angle detected by the steering angle sensor. Note that the inclination sensor  106  can detect the inclination of the vehicle  100  with respect to the perpendicular direction even in a case where a road surface on which the vehicle  100  is traveling is a horizontal road surface as  FIG. 1 ,  FIG. 2A , and  FIG. 2B  and is an inclined road surface such as an upward slope or a downward slope. 
     The inclination sensor  106  generates the condition signal including the detected inclination (inclination signal  118 ) and transmits the condition signal to the vehicle body controller  114 . The vehicle body controller  114  receives the condition signal (inclination signal  118 ), determines the direction of the inclination of the vehicle  100 , and performs arithmetic processing of the condition signal (inclination signal  118 ) so as to correct the inclination of the vehicle  100  and return the position to the perpendicular direction. The first motor driver  115  and the second motor driver  116  respectively control power supply between the battery  109  and the first motor  104  and second motor  105  based on the control signal  121  transmitted from the vehicle body controller  114 . Power supply between the battery  109  and the first motor  104  and second motor  105  is controlled by the first motor driver  115  and the second motor driver  116  based on the control signal  121  transmitted from the vehicle body controller  114 , and the output of the first motor  104  and the output of the second motor  105  can thereby be controlled independently of one another. The output of the first motor  104  and the output of the second motor  105 , which are controlled independently of one another, respectively control the rotational force of the first wheel  101  and the rotational force of the second wheel  102  independently of one another, thereby correcting the inclination of the vehicle  100  and returning the position to the perpendicular direction. In this case, the first motor  104  and the second motor  105  can increase the rotational force of the wheel of the pair of wheels which is positioned on the same side as the inclination or can decrease the rotational force of the wheel which is positioned on the opposite side to the inclination. 
     The activating force sensor  107  of the sensor group is activated by power from the battery  109  and detects the activating force by the driver of the vehicle  100  for propelling the vehicle  100 . In a case where the vehicle  100  is a cycle, as the activating force sensor  107 , a torque sensor is present. As illustrated in  FIG. 1 , the torque sensor is arranged on a shaft that connects a left/right pair of pedals  110  together, detects the torque of the shaft that is rotated by the pedals  110  pushed by the driver of the vehicle  100 , and thereby detects a pedaling effort as the activating force by the driver. Note that the activating force sensor  107  may be any sensor as long as the sensor can detect the activating force exerted by the driver of the vehicle  100 . 
     The activating force sensor  107  generates the condition signal including the detected activating force (activating force signal  119 ) and transmits the condition signal to the vehicle body controller  114 . The vehicle body controller  114  receives the condition signals (inclination signal  118  and activating force signal  119 ) and performs arithmetic processing of the condition signals (inclination signal  118  and activating force signal  119 ) so as to correct the inclination of the vehicle  100  and return the position to the perpendicular direction. The first motor driver  115  and the second motor driver  116  respectively control power supply between the battery  109  and the first motor  104  and second motor  105  based on the control signal  121  transmitted from the vehicle body controller  114  and supply power from the battery  109  to the first motor  104  and the second motor  105  or supply power from the first motor  104  and the second motor  105  to the battery  109 . The outputs of the first motor  104  and second motor  105  whose power supply is controlled are controlled independently of one another similarly to the above, and the rotational force of the first wheel  101  and the rotational force of the second wheel  102  are controlled independently of one another, thereby correcting the inclination of the vehicle  100  and returning the position to the perpendicular direction. 
     The velocity sensor  108  of the sensor group is activated by power from the battery  109 , is arranged on the third wheel  103  as the rear wheel as illustrated in  FIG. 1 , and detects the velocity of the vehicle  100  from the rotational velocity of the third wheel  103 . Note that the velocity sensor  108  may be any sensor as long as the sensor can detect the velocity of the vehicle  100 . Further, the velocity sensor  108  may be arranged on either one of the first wheel  101  and the second wheel  102 . 
     The velocity sensor  108  generates the condition signal including the detected velocity (velocity signal  120 ) and transmits the condition signal to the vehicle body controller  114 . The vehicle body controller  114  receives the condition signals (inclination signal  118 , activating force signal  119 , and velocity signal  120 ) and performs arithmetic processing of the condition signals (inclination signal  118 , activating force signal  119 , and velocity signal  120 ) so as to correct the inclination and return the position to the perpendicular direction. The first motor driver  115  and the second motor driver  116  respectively control power supply between the battery  109  and the first motor  104  and second motor  105  based on the control signal  121  transmitted from the vehicle body controller  114  and supply power from the battery  109  to the first motor  104  and the second motor  105  or supply power from the first motor  104  and the second motor  105  to the battery  109 . The outputs of the first motor  104  and second motor  105  whose power supply is controlled are controlled independently of one another similarly to the above, and the rotational force of the first wheel  101  and the rotational force of the second wheel  102  are controlled independently of one another, thereby correcting the inclination of the vehicle  100  and returning the position to the perpendicular direction. 
     Specifically describing this, in a case where the vehicle  100  becomes unsteady and an inclination is detected by the inclination sensor  106 , the vehicle body controller  114  performs arithmetic processing of the condition signal based on the inclination (inclination signal  118 ) so as to be capable of controlling at least one of the first motor  104  and the second motor  105 . The first motor driver  115  and the second motor driver  116  respectively control power supply between the battery  109  and the first motor  104  and second motor  105  based on the control signal  121  transmitted from the vehicle body controller  114  and supply power from the battery  109  to the first motor  104  and the second motor  105  or supply power from the first motor  104  and the second motor  105  to the battery  109 , thereby correcting the inclination and returning the position to the perpendicular direction. Note that the first motor  104  and the second motor  105  respectively control the torque amounts necessary for the first wheel  101  and the second wheel  102  and times in which torques are exerted and can thereby provide rotational torques to the first wheel  101  and the second wheel  102  independently of one another. “Providing a forward rotational torque” of “providing a rotational torque” represents increasing the rotational force of the wheel by providing a torque in the same direction with respect to the rotation of the wheel in an advancing direction of the vehicle  100 , and “providing a reverse rotational torque” represents decreasing the rotational force of the wheel by providing a torque in the reverse direction with respect to the rotation of the wheel in the advancing direction of the vehicle  100 . Even when the rotational velocity of the wheel is zero, the motor can provide a rotational torque to the wheel. 
     Specifically, in a case where the vehicle  100  is inclined to the left when seen from the driver as illustrated in  FIG. 2B  (an inclination angle θ in the case of  FIG. 2B ), the inclination sensor  106  detects that the vehicle  100  is inclined to the left and transmits the condition signal (inclination signal  118 ) based on the detection (the inclination to the left), and the vehicle body controller  114  performs arithmetic processing of the condition signal (inclination signal  118 ) based on the inclination to the left; the second motor driver  116  supplies power from the battery  109  to the second motor  105  based on the control signal  121  transmitted from the vehicle body controller  114 , and the second motor  105  provides a forward rotational torque to the second wheel  102  on the left side to increase the rotational force of the second wheel  102 ; or the first motor driver  115  supplies power from the battery  109  to the first motor  104  based on the control signal  121  transmitted from the vehicle body controller  114 , and the first motor  104  provides a reverse rotational torque to the first wheel  101  on the right side to decrease the rotational force of the first wheel  101 ; and the rotational forces of the first wheel  101  and the second wheel  102  are controlled independently of one another; thereby correcting the inclination to the left and returning the position to the perpendicular direction (an inclination angle of zero in the case of  FIG. 2A ). Note that in a case where the reverse rotational torque is provided to the first wheel  101  to decrease the rotational force, the first motor  104  is activated as a generator by the first motor driver  115  to cause the first wheel  101  to perform regenerative braking, and power can thereby be supplied from the first motor  104  to the battery  109 . Further, in a case where the vehicle  100  is inclined to the right when seen from the driver, the inclination sensor  106  detects that the vehicle  100  is inclined to the right and transmits the condition signal (inclination signal  118 ) based on the detection (the inclination to the right), and the vehicle body controller  114  performs arithmetic processing of the condition signal (inclination signal  118 ) based on the inclination to the right; the first motor driver  115  supplies power from the battery  109  to the first motor  104  based on the control signal  121  transmitted from the vehicle body controller  114 , and the first motor  104  provides a forward rotational torque to the first wheel  101  on the right side to increase the rotational force of the first wheel; or the second motor driver  116  supplies power from the battery  109  to the second motor  105  based on the control signal  121  transmitted from the vehicle body controller  114 , and the second motor  105  provides a reverse rotational torque to the second wheel  102  on the left side to decrease the rotational force of the second wheel  102 ; and the rotational forces of the first wheel  101  and the second wheel  102  are controlled independently of one another; thereby correcting the inclination to the right and returning the position to the perpendicular direction. Note that in a case where the reverse rotational torque is provided to the second wheel  102  to decrease the rotational force, the second motor  105  is activated as a generator by the second motor driver  116  to cause the second wheel  102  to perform regenerative braking, and power can thereby be supplied from the second motor  105  to the battery  109 . 
     In a case where a reverse rotational torque is provided to the wheel and where the rotational force of the wheel has to be largely decreased in a short time, the motor may be activated as an electric motor. For example, in inclination correction of the vehicle  100  in a case where the vehicle  100  is inclined to the left, in a case where the inclination correction of the vehicle  100  is not adequately made even if the first motor  104  is activated as the generator and causes the first wheel  101  to perform regenerative braking, the first motor  104  is activated as the electric motor to enable the first motor  104  to provide a large reverse rotational torque to the first wheel  101 , and the rotational force of the first wheel  101  may thereby be decreased largely. In such a manner, in a case where a reverse rotational torque is provided to the wheel, necessary and optimal methods for activating the motor may be selected, such as activating the motor as the generator or the electric motor and activating the motor as the electric motor after activating it as the generator. 
     In a case where the vehicle  100  is an electrically-assisted cycle, because the range in which assistance can be performed may be designated by law or the like in accordance with the velocity of the vehicle  100 , a method for controlling the first motor  104  and the second motor  105  may differ in accordance with the velocity of the vehicle  100 . In a case where the velocity of the vehicle  100  detected by the velocity sensor  108  is a prescribed velocity (for example, 24 km/h) or higher, assistance may not be performed. Thus, in order to decrease the rotational force of the wheel positioned on the opposite side to the inclination detected by the inclination sensor  106 , the motor of the wheel provides a reverse rotational torque to the wheel, and the inclination is thereby corrected. 
     Specifically, in a case where the velocity of the vehicle  100  is the prescribed velocity or higher and where the vehicle  100  is inclined to the right, the inclination sensor  106  and the velocity sensor  108  detect that the vehicle  100  is inclined to the right and that the vehicle  100  is at the prescribed velocity or higher and transmit the condition signals (inclination signal  118  and velocity signal  120 ) based on the detection, the vehicle body controller  114  performs arithmetic processing of the condition signal (inclination signal  118 ) based on the inclination to the right and of the condition signal (velocity signal  120 ) based on the velocity, the second motor driver  116  supplies power from the battery  109  to the second motor  105  based on the control signal  121  transmitted from the vehicle body controller  114 , and the second motor  105  provides a reverse rotational torque to the second wheel  102  on the left side to decrease the rotational force of the second wheel  102 , thereby correcting the inclination to the right and returning the position to the perpendicular direction. In this case, the inclination to the right may be corrected such that the first motor  104  and the second motor  105  together provide reverse rotational torques to the first wheel  101  and the second wheel  102 , respectively, but the reverse rotational torque of the second motor  105  is made larger than the reverse rotational torque of the first motor  104 . Further, in a case where the vehicle  100  is inclined to the left, the inclination sensor  106  and the velocity sensor  108  detect that the vehicle  100  is inclined to the left and that the vehicle  100  is at the prescribed velocity or higher and transmit the condition signals (inclination signal  118  and velocity signal  120 ) based on the detection, the vehicle body controller  114  performs arithmetic processing of the condition signal (inclination signal  118 ) based on the inclination to the left and of the condition signal (velocity signal  120 ) based on the velocity, the first motor driver  115  supplies power from the battery  109  to the first motor  104  based on the control signal  121  transmitted from the vehicle body controller  114 , and the first motor  104  provides a reverse rotational torque to the first wheel  101  on the right side to decrease the rotational force of the first wheel  101 , thereby correcting the inclination to the left and returning the position to the perpendicular direction. In this case, the inclination to the left may be corrected such that the first motor  104  and the second motor  105  together provide reverse rotational torques to the first wheel  101  and the second wheel  102 , respectively, but the reverse rotational torque of the first motor  104  is made larger than the reverse rotational torque of the second motor  105 . 
     Further, in a case where the inclination sensor  106  and the velocity sensor  108  detect that the vehicle  100  is inclined in the front-rear direction with respect to the perpendicular direction and that the velocity of the vehicle  100  is decreased or increased such as a case where the vehicle  100  ascends on an upward slope or descends on a downward slope, the inclination sensor  106  and the velocity sensor  108  transmit the condition signals (inclination signal  118  and velocity signal  120 ) based on the detection, the vehicle body controller  114  performs arithmetic processing of the condition signal (inclination signal  118 ) based on the inclination in the front-rear direction and of the condition signal (velocity signal  120 ) based on the increasing or decreasing velocity, and the first motor driver  115  and the second motor driver  116  respectively control power supply between the battery  109  and the first motor  104  and second motor  105  based on the control signal  121  transmitted from the vehicle body controller  114 . In a case where the velocity of the vehicle  100  decreases, the first motor  104  and the second motor  105  respectively provide forward rotational torques to the first wheel  101  and the second wheel  102 , increase the rotational forces, and can thereby increase the velocity of the vehicle  100 . Further, in a case where the velocity of the vehicle  100  increases, the first motor  104  and the second motor  105  respectively provide reverse rotational torques to the first wheel  101  and the second wheel  102 , decrease the rotational force of the wheel  102 , and can thereby decrease the velocity of the vehicle  100 . 
     Usually, the first motor  104  and the second motor  105  are respectively activated as electric motors so as to be capable of converting electric energy (power) supplied from the battery  109  into kinetic energy (travel energy of the vehicle  100 ) and thereby control the first wheel  101  and the second wheel  102 . However, each of the first motor  104  and the second motor  105  may be activated as a generator. The first motor  104  and second motor  105  activated as the generators respectively cause the first wheel  101  and the second wheel  102  to perform regenerative braking, thereby provide reverse rotational torques to the first wheel  101  and the second wheel  102  to decrease the rotational forces, and can further convert the kinetic energy (the travel energy of the vehicle  100 ) into electric energy (power) to recover the electric energy to the battery  109 . For example, in a case where it is determined that the inclination direction is right and the velocity of the vehicle  100  is a prescribed value or greater, the second motor driver  116  activates the second motor  105  as the generator based on the control signal  121  transmitted from the vehicle body controller  114 , the second motor  105  causes the second wheel  102  on the left side to perform regenerative braking, thereby provide a reverse rotational torque to the second wheel  102  to decrease the rotational force of the second wheel  102 , further converts the travel energy of the vehicle  100  into power, and may thereby recover the travel energy of the vehicle  100  such that a current flows from the second motor  105  to the battery  109  and power is returned (supplied) from the second motor  105  to the battery  109 . 
     In a case where the vehicle  100  is an electrically-assisted cycle, because assistance can be performed when the driver of the vehicle  100  exerts the pedaling force as the activating force, a method for controlling the first motor  104  and the second motor  105  may differ in accordance with the activating force. In a case where the velocity of the vehicle  100  detected by the velocity sensor  108  is lower than a prescribed velocity and where the activating force is detected by the activating force sensor  107 , assistance can be performed. Thus, the rotational force of the wheel positioned on the same side as the inclination detected by the inclination sensor  106  is controlled, the motor of the wheel provides a forward rotational torque to the wheel, and the inclination is thereby corrected. 
     Specifically, in a case where the velocity of the vehicle  100  is lower than the prescribed velocity and the activating force is detected and where the vehicle  100  is inclined to the right, the inclination sensor  106 , the activating force sensor  107 , and the velocity sensor  108  detect that the vehicle  100  is inclined to the right, that the activating force by the driver is present, and that the vehicle  100  is at a lower velocity than the prescribed velocity and transmit the condition signals (inclination signal  118 , activating force signal  119 , and velocity signal  120 ) based on the detection, the vehicle body controller  114  performs arithmetic processing of the condition signal (inclination signal  118 ) based on the inclination to the right, of the condition signal (activating force signal  119 ) based on the activating force, and of the condition signal (velocity signal  120 ) based on the velocity, the first motor driver  115  controls power supply between the battery  109  and the first motor  104  based on the control signal  121  transmitted from the vehicle body controller  114 , and the first motor  104  provides a forward rotational torque to the first wheel  101  on the right side to increase the rotational force of the first wheel  101 , thereby correcting the inclination to the right and returning the position to the perpendicular direction. In this case, the inclination to the right may be corrected such that the first motor  104  and the second motor  105  together provide forward rotational torques to the first wheel  101  and the second wheel  102 , respectively, but the forward rotational torque of the first motor  104  is made larger than the forward rotational torque of the second motor  105 . Further, in a case where the vehicle  100  is inclined to the left, the inclination sensor  106 , the activating force sensor  107 , and the velocity sensor  108  detect that the vehicle  100  is inclined to the left, that the activating force by the driver is present, and that the vehicle  100  is at a lower velocity than the prescribed velocity and transmit the condition signals (inclination signal  118 , activating force signal  119 , and velocity signal  120 ) based on the detection, the vehicle body controller  114  performs arithmetic processing of the condition signal (inclination signal  118 ) based on the inclination to the left, of the condition signal (activating force signal  119 ) based on the activating force, and of the condition signal (velocity signal  120 ) based on the velocity, the second motor driver  116  controls power supply between the battery  109  and the second motor  105  based on the control signal  121  transmitted from the vehicle body controller  114 , and the second motor  105  provides a forward rotational torque to the second wheel  102  on the left side to increase the rotational force of the second wheel  102 , thereby correcting the inclination to the left and returning the position to the perpendicular direction. In this case, the inclination to the left may be corrected such that the first motor  104  and the second motor  105  together provide forward rotational torques to the first wheel  101  and the second wheel  102 , respectively, but the forward rotational torque of the second motor  105  is made larger than the forward rotational torque of the first motor  104 . 
     Note that in this case, power is supplied from the battery  109  to the motor that provides the forward rotational torque. For example, in a case where the inclination direction is right, the velocity of the vehicle  100  is lower than a prescribed value, and the activating force is present, in order to increase the rotational force of the first wheel  101  on the right side, the first motor driver  115  causes a current to flow from the battery  109  to the motor that increases the rotational force of the first wheel  101 , that is, the first motor  104  based on the control signal  121  transmitted from the vehicle body controller  114 , power is supplied from the battery  109  to the first motor  104 , and the first motor  104  provides a forward rotational torque to the first wheel  101 . 
     In a case where the velocity of the vehicle  100  detected by the velocity sensor  108  is lower than the prescribed velocity and where the activating force is not detected by the activating force sensor  107 , assistance may not be performed. Thus, the motor, which controls the rotational force of the wheel positioned on the opposite side to the inclination detected by the inclination sensor  106 , provides a reverse rotational torque to the wheel and thereby corrects the inclination. A specific method for correcting an inclination is similar to the above method in a case where the velocity of the vehicle  100  is the prescribed velocity or higher. 
     Note that in this case, the motor that provides the reverse rotational torque to the wheel is activated as the generator and causes the wheel to perform regenerative braking, the travel energy of the vehicle  100  is thereby recovered by the motor, and power may be returned (supplied) to the battery  109 . For example, in a case where it is determined that the inclination direction is right, the velocity of the vehicle  100  is lower than a prescribed value, and the activating force is not present, the second motor driver  116  activates the motor that decreases the rotational force of the second wheel  102  on the left side, that is, the second motor  105  as the generator and causes the second wheel  102  to perform regenerative braking based on the control signal  121  transmitted from the vehicle body controller  114 , the travel energy of the vehicle  100  is thereby recovered, a current flows from the second motor  105  to the battery  109 , power is returned (supplied) from the second motor  105  to the battery  109 , and further the second motor  105  activated as the generator may provide a reverse rotational torque to the second wheel  102 . 
     Further, in a case where an inclination is not detected by the inclination sensor  106  and the vehicle  100  is not unsteady and where the velocity of the vehicle  100  detected by the velocity sensor  108  is lower than the prescribed velocity and the activating force is detected by the activating force sensor  107 , assistance can be performed. Thus, the vehicle body controller  114  performs arithmetic processing of the condition signals (inclination signal  118 , activating force signal  119 , and velocity signal  120 ), the first motor driver  115  and the second motor driver  116  respectively control power supplied from the battery  109  based on the control signal  121  transmitted from the vehicle body controller  114 , supply power to the first motor  104  and the second motor  105 , and control the output of the first motor  104  and the output of the second motor  105  independently of one another, and the first motor  104  and the second motor  105  respectively provide forward rotational torques to the first wheel  101  and the second wheel  102  to increase the rotational forces of the first wheel  101  and the second wheel  102 . 
     The position of the vehicle  100  is likely to become unsteady also when the driver starts driving of the vehicle  100 . Accordingly, when the driving of the vehicle  100  is started by the driver, the first motor  104  and the second motor  105  respectively provide slight rotational torques to the first wheel  101  and the second wheel  102 , and the position of the vehicle  100  may thereby be stabilized. In this case, the activating force sensor  107  and the velocity sensor  108  are used to determine whether or not the driving of the vehicle  100  is started. In a case where an inclination is detected by the inclination sensor  106 , the first motor  104  and the second motor  105  may respectively provide slight rotational torques to the first wheel  101  and the second wheel  102  in accordance with the detection. 
     Specifically, in a case where the vehicle  100  stands still and the driver does not exert the activating force and where the vehicle  100  is inclined to the right, the inclination sensor  106 , the activating force sensor  107 , and the velocity sensor  108  detect that the vehicle  100  is inclined to the right, that the activating force by the driver is not present, and that the vehicle  100  stands still and transmit the condition signals (inclination signal  118 , activating force signal  119 , and velocity signal  120 ) based on the detection, the vehicle body controller  114  performs arithmetic processing of the condition signal (inclination signal  118 ) based on the inclination to the right, of the condition signal (activating force signal  119 ) based on the activating force, and of the condition signal (velocity signal  120 ) based on the velocity and thereby determines that the driving of the vehicle  100  is started, and the first motor driver  115  and the second motor driver  116  respectively control power supplied from the battery  109  based on the control signal  121  transmitted from the vehicle body controller  114  and supply power to the first motor  104  and the second motor  105 . Then, the first motor  104  that controls the rotational force of the first wheel  101  on the right side provides a slight forward rotational torque to the first wheel  101  and causes the first wheel  101  to slightly rotate with respect to the same direction as the advancing direction of the vehicle  100 , and the second motor  105  that controls the rotational force of the second wheel  102  on the left side provides a slight reverse rotational torque to the second wheel  102  and causes the second wheel  102  to slightly rotate with respect to the opposite direction to the advancing direction of the vehicle  100 , thereby correcting the inclination to the right and returning the position to the perpendicular direction. In this case, control may be performed either by the first motor  104  providing the slight forward rotational torque to the first wheel  101  or by the second motor  105  providing the slight reverse rotational torque to the second wheel  102 . Further, in a case where the vehicle  100  is inclined to the left, the inclination sensor  106 , the activating force sensor  107 , and the velocity sensor  108  detect that the vehicle  100  is inclined to the left, that the activating force by the driver is not present, and that the vehicle  100  stands still and transmit the condition signals (inclination signal  118 , activating force signal  119 , and velocity signal  120 ) based on the detection, the vehicle body controller  114  performs arithmetic processing of the condition signal (inclination signal  118 ) based on the inclination to the left, of the condition signal (activating force signal  119 ) based on the activating force, and of the condition signal (velocity signal  120 ) based on the velocity and thereby determines that the driving of the vehicle  100  is started, and the first motor driver  115  and the second motor driver  116  respectively control power supplied from the battery  109  based on the control signal  121  transmitted from the vehicle body controller  114  and supply power to the first motor  104  and the second motor  105 . Then, the second motor  105  that controls the rotational force of the second wheel  102  on the left side provides a slight forward rotational torque to the second wheel  102  and causes the second wheel  102  to slightly rotate with respect to the same direction as the advancing direction of the vehicle  100 , and the first motor  104  that controls the rotational force of the first wheel  101  on the right side provides a slight reverse rotational torque to the first wheel  101  and causes the first wheel  101  to slightly rotate with respect to the opposite direction to the advancing direction of the vehicle  100 , thereby correcting the inclination to the left and returning the position to the perpendicular direction. In this case, control may be performed either by the second motor  105  providing the slight forward rotational torque to the second wheel  102  or by the first motor  104  providing the slight reverse rotational torque to the first wheel  101 . Note that in a case where the vehicle  100  is a cycle, a sensor such as a load cell is further placed below the saddle  111 , a determination is made whether or not the driver rides on the vehicle  100 , that is, whether or not the driving of the vehicle  100  is started based on detection of a load by the sensor such as the load cell. In a case where an inclination is detected by the inclination sensor  106 , the first motor  104  and the second motor  105  may respectively provide the slight rotational 
     Next, a description will be made about a method for controlling the vehicle  100  in which at least one of the front wheel section and the rear wheel section is configured from a pair of wheels which have the right wheel as the first wheel  101  and the left wheel as the second wheel  102  and which can be propelled by the activating force of the driver. The method includes steps of detecting the conditions of the vehicle  100  and steps of controlling the rotational forces of the pair of wheels  101  and  102  independently of one another in response to the detection. 
     A detailed description will be made, by using the flowchart illustrated in  FIG. 5 , about a method for controlling the vehicle  100  that includes a pair of motors configured from the first motor  104  on the right side and the second motor  105  on the left side, which are respectively arranged on the pair of wheels. In STEP  100 , detection results by the inclination sensor  106 , the activating force sensor  107 , and the velocity sensor  108 , which are included in the vehicle  100 , are read. Next, in STEP  101 , a determination is made whether or not an inclination of the vehicle  100  is present based on the detection result by the inclination sensor  106 . In a case where a determination is made that an inclination is not present, in STEP  102 , a determination is made whether the velocity of the vehicle  100  is a higher velocity or a lower velocity than a prescribed velocity based on the detection result by the velocity sensor  108 . In a case where a determination is made that the velocity is a lower velocity, in STEP  103 , a determination is made whether or not the activating force by the driver is present based on the detection result by the activating force sensor  107 . In a case where a determination is made that the activating force is present, in STEP  104 , the right motor and the left motor respectively apply forward rotational torques to the right wheel and the left wheel. 
     In a case where a determination is made that an inclination is present in STEP  101 , in STEP  105 , a determination is made whether or not the driving of the vehicle  100  is started. Whether or not the driving of the vehicle  100  is started may be determined based on the detection results by the activating force sensor  107  and the velocity sensor  108 . 
     In a case where a determination is made that the driving is not started in STEP  105 , in STEP  106 , the inclination direction of the vehicle  100  is determined. Note that although the vehicle  100  is inclined with respect to the perpendicular direction in both of left turn and right turn of the vehicle  100 , in a case where a determination is made that the inclination is not due to unsteadiness but left turn or right turn, steps of STEPs  107  to  116  described in the following are set not to be performed. 
     In STEP  106 , in a case where a determination is made that the inclination occurs to the left, the inclination to the left is corrected, and the position is returned to the perpendicular direction. However, control methods of the right motor and the left motor differ in accordance with the velocity of the vehicle  100  and the activating force. In STEP  107 , a determination is made whether the velocity of the vehicle  100  is a higher velocity or a lower velocity than a prescribed velocity based on the detection result by the velocity sensor  108 . In a case where a determination is made that the velocity is a higher velocity, in STEP  108 , the right motor applies a reverse rotational torque to the right wheel to decrease the rotational force of the right wheel and thereby corrects the inclination to the left. In this case, the inclination to the left may be corrected such that the right motor and the left motor together apply reverse rotational torques to the right wheel and the left wheel, respectively, but the reverse rotational torque of the right motor is made larger than the reverse rotational torque of the left motor. Note that in a case where a reverse rotational torque is applied, the motor may be activated as a generator and cause the wheel to perform regenerative braking. In a case where a determination is made that the velocity is a lower velocity in STEP  107 , in STEP  109 , a determination is made whether or not the activating force by the driver is present based on the detection result by the activating force sensor  107 . In a case where a determination is made that the activating force is not present, in STEP  110 , the right motor applies a reverse rotational torque to the right wheel to decrease the rotational force of the right wheel and thereby corrects the inclination to the left. In this case, the inclination to the left may be corrected such that the right motor and the left motor together apply reverse rotational torques to the right wheel and the left wheel, respectively, but the reverse rotational torque of the right motor is made larger than the reverse rotational torque of the left motor. Note that in a case where a reverse rotational torque is applied, the motor may be activated as the generator and cause the wheel to perform regenerative braking. Further, the left motor may apply a slight forward rotational torque to the left wheel and slightly increase the rotational force of the left wheel. In a case where a determination is made that the activating force is present in STEP  109 , in STEP  111 , the left motor applies a forward rotational torque to the left wheel to increase the rotational force of the left wheel and thereby corrects the inclination to the left. In this case, the inclination to the left may be corrected such that the right motor and the left motor together apply forward rotational torques to the right wheel and the left wheel, respectively, but the forward rotational torque of the left motor is made larger than the forward rotational torque of the right motor. 
     In STEP  106 , in a case where a determination is made that the inclination occurs to the right, the inclination to the right is corrected, and the position is returned to the perpendicular direction. However, control methods of the right motor and the left motor differ in accordance with the velocity of the vehicle  100  and the activating force. In STEP  112 , a determination is made whether the velocity of the vehicle  100  is a higher velocity or a lower velocity than a prescribed velocity based on the detection result by the velocity sensor  108 . In a case where a determination is made that the velocity is a higher velocity, in STEP  113 , the left motor applies a reverse rotational torque to the left wheel to decrease the rotational force of the left wheel and thereby corrects the inclination to the right. In this case, the inclination to the right may be corrected such that the right motor and the left motor together apply reverse rotational torques to the right wheel and the left wheel, respectively, but the reverse rotational torque of the left motor is made larger than the reverse rotational torque of the right motor. Note that in a case where a reverse rotational torque is applied, the motor may be activated as the generator and cause the wheel to perform regenerative braking. In a case where a determination is made that the velocity is a lower velocity in STEP  112 , in STEP  114 , a determination is made whether or not the activating force by the driver is present based on the detection result by the activating force sensor  107 . In a case where a determination is made that the activating force is not present, in STEP  115 , the left motor applies a reverse rotational torque to the left wheel to decrease the rotational force of the left wheel and thereby corrects the inclination to the right. In this case, the inclination to the right may be corrected such that the right motor and the left motor together apply reverse rotational torques to the right wheel and the left wheel, respectively, but the reverse rotational torque of the left motor is made larger than the reverse rotational torque of the right motor. Note that in a case where a reverse rotational torque is applied, the motor may be activated as the generator and cause the wheel to perform regenerative braking. Further, the right motor may apply a slight forward rotational torque to the right wheel and slightly increase the rotational force of the right wheel. In a case where a determination is made that the activating force is present in STEP  114 , in STEP  116 , the right motor applies a forward rotational torque to the right wheel to increase the rotational force of the right wheel and thereby corrects the inclination to the right. In this case, the inclination to the right may be corrected such that the right motor and the left motor together apply forward rotational torques to the right wheel and the left wheel, respectively, but the forward rotational torque of the right motor is made larger than the forward rotational torque of the left motor. 
     In a case where a determination is made that the driving of the vehicle  100  is started in STEP  105 , in STEP  117 , the inclination direction of the vehicle  100  is determined. In a case where a determination is made that the inclination occurs to the left in STEP  117 , in STEP  118 , the right motor applies a slight reverse rotational torque to the right wheel to cause the right wheel to slightly rotate with respect to the opposite direction to the advancing direction of the vehicle  100 , and/or the left motor applies a slight forward rotational torque to the left wheel to cause the left wheel to slightly rotate with respect to the same direction as the advancing direction of the vehicle  100 , thereby correcting the inclination to the left and returning the position to the perpendicular direction. Further, in a case where a determination is made that the inclination occurs to the right in STEP  117 , in STEP  119 , the left motor applies a slight reverse rotational torque to the left wheel to cause the left wheel to slightly rotate with respect to the opposite direction to the advancing direction of the vehicle  100 , and/or the right motor applies a slight forward rotational torque to the right wheel to cause the right wheel to slightly rotate with respect to the same direction as the advancing direction of the vehicle  100 , thereby correcting the inclination to the right and returning the position to the perpendicular direction. 
     A vehicle in which at least one of a front wheel section and a rear wheel section is configured from a left/right pair of wheels and which can be propelled by rotating a wheel by an activating force of a driver of the vehicle includes a wheelchair and a wheelbarrow in addition to a cycle with three or more wheels. 
     It should be further understood by persons skilled in the art that although the foregoing descriptions have been made on embodiments of the present invention, the present invention is not limited thereto and various changes and modifications may be made without departing from the spirit of the present invention and the scope of the appended claims. 
     REFERENCE SIGNS LIST 
     
         
           100  vehicle 
           101  first wheel 
           102  second wheel 
           103  third wheel 
           104  first motor 
           105  second motor 
           106  inclination sensor 
           107  activating force sensor 
           108  velocity sensor 
           109  battery 
           110  pedal 
           111  saddle 
           112  handle 
           113  suspension mechanism 
           114  vehicle body controller 
           115  first motor driver 
           116  second motor driver 
           117  control device 
           118  inclination signal 
           119  activating force signal 
           120  velocity signal 
           121  control signal 
           122  suspension shaft 
           123  first arm 
           124  second arm