Abstract: An electric vehicle has a control unit having a decelerating control function of decelerating an electric motor disposed on a side of a vehicle body corresponding to a turning direction of the electric vehicle, and an accelerating control function of outputting an accelerating control signal for performing acceleration control to accelerate the electric motor when operation of the electric vehicle is switched from a first traveling mode to a second traveling mode. When the electric motor has a speed not exceeding a predetermined reference speed, the accelerating control function performs the acceleration control such that a level of the accelerating control signal is increased abruptly for a temporary time from the switching of the operation of the electric vehicle from the first traveling mode to the second traveling mode.

Abstract: The recreational electric vehicle (hereinafter REV) is a convenient indoor or outdoor vehicle for one or two people with a space for personal goods. REV is most suited for adaptations for recreational use. It uses electric power for zero pollutant emissions, quiet operation, and a very low running cost. REV is driven using a joystick and is able to turn on the spot.

Abstract: A driving device of a robot cleaner with a shock-absorbing unit. The driving device includes a robot cleaner body and a pair of motors disposed in the robot cleaner body which are driven by respective power supplies. The driving device also includes a pair of driving wheels rotated by the pair of motors, a pair of driven wheels following the pair of driving wheels, and a driving force transmitting means which causes the driving wheels and the driven wheels to move in association with each other. A frame unit is disposed in the robot cleaner body to support the pair of driving wheels and the pair of driven wheels, and a shock-absorbing unit is disposed in the frame unit to absorb shock that occurs from a cleaning surface.

Abstract: The disclosed invention used power-assist wheelchair hubs and an array of sensors to provide obstacle-avoidance features on a wheelchair. In a power-assisted manual wheelchair, the traditional rear wheels are replaced with motorized hubs that magnify the force applied to the rear wheels by the user. The present invention uses sensors to detect obstacles and drop-offs near the wheelchair, and uses the power-assist hubs to alter wheelchair movement in response to these sensor readings.

Abstract: There are two basic methods of steering a wheeled vehicle. One method is to turn one or more steerable wheels. The other is to drive one or more left hand wheels independently of one or more right hand wheels. Traditional vehicles address the potential conflict between the two steering systems by either disabling one system or by causing one to overpower the other. This leads to skidding or scuffing problems respectively. In the present invention both steering systems are enabled but are integrated by means of an on board computer so that they always act in unison. This mutual reinforcement will allow the invention to operate safely on steep or slippery slopes while minimizing fuel consumption and ground damage. The invention will also be more maneuverable than traditional vehicles since it is capable of both pure rotation and pure translation or any combination of rotation and translation.

Abstract: A system and method of controlling a multi-wheel drive vehicle is provided. The invention is preferably applicable to the steering of such a vehicle and determines the individual velocities for each wheel drive. In this regard, the invention includes two general steps. The first step includes determining the distance of each wheel drive and a vehicle velocity reference point from a turning reference point. The second step includes ratioing each wheel drive's distance from the turning reference point with the vehicle velocity reference point's distance from the turning reference point. The ratios are then applied to a vehicle velocity associated with the vehicle velocity reference point to determine the velocity of each respective wheel drive. Once determined, the velocities are output to each wheel drive.

Abstract: A transporter for transporting a subject over a surface that may be irregular. The transporter includes a support platform for supporting a load, the loaded support platform defining fore-aft and lateral planes and characterized by a load distribution. A plurality of ground contacting elements are coupled to the support platform such that the transporter is statically stable with respect to tipping in the fore-aft plane. At least one of the plurality of ground contacting elements is driven by a motorized drive arrangement. A sensor module generates a signal indicative of the load distribution. Based at least on the load distribution, a controller commands the motorized drive arrangement.

Abstract: An autonomous robot, that is for example, suitable for operations such as vacuuming and surface cleaning includes a payload configured for vacuum cleaning, a drive system including a steering system, a navigation system, and a control system for integrating operations of the aforementioned systems.

Abstract: A method for compensating a rotational position error of a robot cleaner is disclosed to reduce a rotational position error of a robot cleaner by compensating an offset value of a gyro sensor of the robot cleaner. The method includes: detecting an offset value of a sensor for detecting a rotational speed of a robot cleaner; compensating the detected offset value; and correcting a rotational position of the robot cleaner on the basis of the compensated offset value.

Abstract: An articulated forklift truck for use in narrow aisles comprises a front chassis section (10) having a first pair of ground-engaging wheels (20) and a rear chassis section (12) having a second pair of ground-engaging wheels (22). The front chassis section (10) carries a mast (16) and lift forks (18) and is pivoted to the rear chassis section (12) about a substantially vertical axis (14) to allow the truck to be steered. Both front wheels (20) but only one of the rear wheels (22) are driven by electric of hydrostatic motors (24, 26).

Abstract: A robotic cart pulling vehicle includes a positioning error reducing system for reducing accumulated error in the ded-reckoning navigational system. The positioning error reducing system including at least one of a low load transfer point of the cart attaching mechanism, a floor variation compliance structure whereby the drive wheels maintain a substantially even distribution of load over minor surface variations, a minimal wheel contact surface structure, a calibration structure using at least one proximity sensor mounted on the robot body, and a common electrical and mechanical connection between the cart and the robot vehicle formed by a cart attaching post.

Abstract: A motorized vehicle has a vehicle body, at least a pair of wheels mounted on the vehicle body for undergoing rotation to cause the motorized vehicle to undergo travelling, and a pair of electric motors each mounted on the vehicle body to selectively undergo forward and reverse rotation to rotationally drive a respective one of the wheels. A first switch is connected to the electric motors so that operation of the first switch causes the electric motors to undergo rotation simultaneously in opposite directions to turn the motorized vehicle in a first direction while the motorized vehicle does not undergo travelling. A second switch is connected to the electric motors so that operation of the second switch causes the electric motors to undergo rotation simultaneously in opposite directions to turn the motorized vehicle in a second direction opposite to the first direction while the motorized vehicle does not undergo travelling.

Abstract: An electric drive configuration for a skid steered vehicle comprises: a pair of propulsion motors (74a, 74b), each with a motor shaft protruding from both ends of the motor and mounted on the same axis across the vehicle, each being coupled at the outer end to drive one of a pair of tracks or set of wheels of the skid steered vehicle; a control differential steep gear unit (72) positioned between the two propulsion motors and in driveable communication with the inner ends of the two motor shafts: and a steer motor (71) in driveable communication with the controlled differential (72), the steer motor (71) being controllable from zero speed giving straight line running in which both motor shafts are coupled to run at the same speed, to a range of speeds in both directions of rotation giving steering capability in both directions.

Abstract: A wireless remote controlled rover (100) having a circular outer boundary when viewed in profile, comprising an elongated round-profile frame (20) outfitted with a pair of omnidirectional wheels (101L,R), rotatable in opposite directions by a drive system (50), for steering. Each of omnidirectional wheels (101L,R) comprises a set of secondary wheels (150L,R) akin to large diameter hollow flexible shafts arcuately bent and distributed in a polar array about corresponding hubs (82L,R). The secondary wheels (150L,R) are rotatable by the drive system (50) for longitudinal thrust of rover (100). A user controls the steering and thrust actions via remote control (166) for navigation and to compensate for incidental inertial rolling/careening effects of the two-wheel round-profile rover (100) while in motion. An onboard intelligent electronic processing unit (33) uses sensory feedback for autopilot, or assistive navigation, during certain scenarios such as performing user-requested optimum stopping maneuvers.

Abstract: A device of a cart includes a control, a speed regulating potentiometer, a microprocessor, a digital-to-analogue converter, a motor controlling unit, and a switch; the control is angularly displaceable and near to handlebars of the cart; the potentiometer is connected to the control so as to output a voltage, which depends on displacement of the control; the microprocessor can produce digital signals according to the output voltage of the potentiometer; the converter is used for converting the digital signals into analogue voltage; the motor controlling unit is used for making a motor run at a variable-speed mode, at which mode the speed of the motor will depend on output voltage of the converter; immediately after the rider presses the switch, the microprocessor will ignore output voltage of the potentiometer, and start and continue giving a same digital signal to the converter so that the motor starts running at constant speed.

Abstract: A two-wheel electric vehicle with ringlike, large, powered parallel wheels, in which at least one ringlike wheel is driven by a large toroidal electric motor. The fully circular rotor of the large toroidal electric motor is integrated with the hub of the ringlike wheel, while the circular or semi-circular toroidal stator is joined to the body of the two-wheel electric vehicle, the ringlike wheel and the toroidal electric motor having a common bearing. The electric power source to drive the toroidal electric motor is located near the ground-facing portion of the vehicle body. An opening is formed in the internal circular area of the toroidal stator, to allow the entry and exit of the passengers of the vehicle. A similar small vehicle with parallel, coaxial wheels allows the occupant of the small vehicle to travel, seated either facing the conventional front or the rear of the small vehicle.

Abstract: Disclosed is a driving apparatus for a robot cleaner enabling drive wheels to be in contact with a floor all the time. The driving apparatus for a robot cleaner includes a robot cleaner main body, driving motors mounted in the robot cleaner main body, and for transferring power to drive wheels, driving motor housings hinged with the robot cleaner main body, and for accommodating the driving motors therein, and pressure members disposed between the robot cleaner main body and the driving motor housings, and for pressing the driving motor housings. Accordingly, the driving motor housings are mounted to rotate about the center of the rotation hinges so that the drive wheels come in contact with the floor all the time, preventing the drive wheels from being lifted over the floor and making lost rotations due to curved portions of the floor or obstacles.

Abstract: The left and right rear drive wheels of a vehicle are controlled independently, and the traveling direction of the vehicle is changed by providing a rotational speed difference between each of the left and right rear drive wheel. A vehicle operator merely designates the turning direction by moving an operation stick, e.g., to the left or right, which will in turn enable an automatic turn at an optimum curvature to be performed which frees the vehicle operator from complicated steering operations. A highly precise and responsive turn is achieved when the left and right independent control is implemented with a PLL control circuit.

Abstract: A personal transporter device and corresponding method of operation are given that utilize an exercise mode. A transporter assembly includes a platform, a ground-contacting module, and a motorized drive. The platform supports a user. The ground-contacting module is connected to the platform. The motorized drive powers the ground-contacting module to drive the assembly in a selected direction over an underlying surface. A controller is coupled to and controlling the motorized drive, and also has an exercise mode for opposing a user-provided human power input with a selected level of resistance. When the device is a dynamically stabilized transporter, the controller also controls the motorized drive so as to dynamically stabilize the transporter assembly.

Abstract: A device and methods for supporting a payload, such as a user, at a variable height above the ground and for repositioning the payload in a dynamically stabilized mode of operation. The transporter device has two laterally disposed primary wheels and a payload support that may be used to raise or lower the payload. A torque is applied to the laterally disposed wheels so as to propel the transporter on the basis of a control signal that may include repositioning of the device.

Abstract: A battery powered motor vehicle for transporting a rider in a standing position can be steered by either selective distribution of the riders weight, or alternative by turning a steering console. By attaching a cargo rack, the battery powered motor vehicle can be converted to a hand truck for transporting cargo. In the hand truck mode, the battery powered motor vehicle can either be powered wherein the vehicle moves in reverse, or manually pushed wherein the vehicle is in a neutral state.

Abstract: A power steering system capable of giving a driver no discomfort even when an incoming current instruction value sharply decreases. The power steering system comprises a controller C for determining a solenoid current instruction value SI on the basis of a current instruction value I1 in accordance with a steering angle supplied from a steering angle sensor, a current instruction value I2 in accordance with a steering angular velocity, and a current instruction value in accordance with a vehicle speed. The controller C comprises a delay control section for reducing the rate of decrease only when the incoming current instruction value sharply decreases and outputting the resulting current instruction value.

Abstract: A power steering system capable of preventing an unnecessary standby flow produced in high speed travel. A controller C determines a basic current instruction value Id based on a current instruction value I1 in accordance with a steering angle detected by a steering angle sensor 14, a current instruction value I2 in accordance with a steering angular velocity and current instruction values I5, I6 in accordance with a vehicle speed, and adds a standby current instruction value Is to the basic current instruction value Id, and outputs the resultant value of the addition as a solenoid current instruction value SI, and changes the standby current instruction value Is on the basis of the vehicle speed.

Abstract: An electric-powered vehicle includes electric-powered drivers for driving wheels, a controller for controlling the electric-powered drivers to generate an assisting driving force in accordance with a vehicle operating force by an operator, and a brake-operation unit for applying braking forces on the wheels. The vehicle also includes a brake-operation detector for detecting a brake operation performed by the brake-operation unit. When the brake-operation detector detects the brake operation, the controller controls the drivers to reduce the assisting driving force. This structure solves a problem caused by simultaneous generation of the braking forces and the assisting driving force.

Abstract: A motorized vehicle has a vehicle body, at least a pair of wheels mounted on the vehicle body for undergoing rotation to cause the motorized vehicle to undergo travelling, and a pair of electric motors each mounted on the vehicle body to selectively undergo forward and reverse rotation to rotationally drive a respective one of the wheels. A first switch is connected to the electric motors so that operation of the first switch causes the electric motors to undergo rotation simultaneously in opposite directions to turn the motorized vehicle in a first direction while the motorized vehicle does not undergo travelling. A second switch is connected to the electric motors so that operation of the second switch causes the electric motors to undergo rotation simultaneously in opposite directions to turn the motorized vehicle in a second direction opposite to the first direction while the motorized vehicle does not undergo travelling.

Abstract: An electronic control system for a wheeled electric cart is disclosed. In response to a turning of the cart, a direction change signal proportional to an angle of rotation is generated by a steering controller and sensed by an angle of rotation sensor, and an electronic differential is adapted to receive a direction change signal and a speed signal respectively, perform a function about a distance between two rear wheels and a distance between front and rear wheels at the same side, the direction change signal, and the speed signal to generate a speed and direction change signal, transmit the speed and direction change signal to left and right motors for causing the left and right motor to rotate at different speeds, and cause the left and right wheels to turn in different speeds accordingly. The invention can carry out high transmission efficiency while turning curves.

Abstract: A system for mobile robots to detect obstructions. Obstructions include objects which may impair the or impede the mobility of the robot, as well as transitions from carpeted surfaces to hard surfaces, transitions from hard surfaces to carpet, or transitions between other types of flooring. The system includes a plow which may move underneath the obstruction, The obstruction may the be brushed aside, or rise to an elevation detectable by the robot. Upon detection, the robot may change its direction of movement or stop moving altogether.

Abstract: A motorized vehicle has wheels mounted on a vehicle body for undergoing rotation to cause the motorized vehicle to undergo travelling, electric motors for selectively undergoing forward and reverse rotation to rotationally drive respective ones of the wheels, brakes for applying brake forces to respective ones of the wheels, handlebars extending from the vehicle body, and turn control levers mounted on the handlebars to undergo angular movement within a range of preselected angular positions. The turn control levers are connected to respective ones of the brakes and respective ones of the electric motors so that the electric motors undergo rotation simultaneously in opposite directions in accordance with the preselected angular positions of the turn control levers to turn the motorized vehicle while the motorized does not undergo travelling.

Abstract: Disclosed is a driving apparatus for a robot cleaner enabling drive wheels to be in contact with a floor all the time. The driving apparatus for a robot cleaner includes a robot cleaner main body, driving motors mounted in the robot cleaner main body, and for transferring power to drive wheels, driving motor housings hinged with the robot cleaner main body, and for accommodating the driving motors therein, and pressure members disposed between the robot cleaner main body and the driving motor housings, and for pressing the driving motor housings. Accordingly, the driving motor housings are mounted to rotate about the center of the rotation hinges so that the drive wheels come in contact with the floor all the time, preventing the drive wheels from being lifted over the floor and making lost rotations due to curved portions of the floor or obstacles.

Abstract: A two wheeled automotive vehicle having a heavily weighted passenger compartment pivotally mounted on, and with its center of gravity below, a trapeze cross bar that is in turn pivotally mounted between axially aligned stub axles for the road wheels. Attitude control is provided and other function for controlling the reactive forces of braking is also disclosed.

Abstract: A mobile X-ray apparatus has a carriage provided with at least one pair of independently driven driving wheels and a motor. The carriage includes a driving handle, which comprises sidebars, attached to a rotation axis solidly fixed to the carriage, and a crossbar, which is connected to the sidebars in an articulated manner to allow the turning movement of the sidebars about the said axis independently of each other. The apparatus also controls the operation of the motor by movements of the handle. The sidebars are provided with a toothed rim that moves along with the movement of the respective sidebar. The movements are measured by a potentiometer, which converts the movement into an electric signal by which the motor of the driving wheels is controlled.

Abstract: A method for operating a vehicle having variable-speed left-side and right-side propulsion units (such as, without limitation, a tracked vehicle having a left track powered by a left-track motor and a right track powered by a right-track motor). The left-side propulsion unit is controlled by a first output signal from a first manual controller (such as, without limitation, a left joystick). The right-side propulsion unit is controlled by a second output signal from a second manual controller (such as, without limitation, a right joystick). At least one of the first and second output signals is modified to create a substantially identical output signal for the first and second manual controllers when the first and second output signals are within a predetermined tolerance. The left-side and right-side propulsion units are controlled with the identical output signal when the first and second output signals are within the predetermined tolerance.

Abstract: A motorized wheelchair is advantageously provided with a rate-of-turn feedback sensor and with forward/reverse motion, lateral motion, and vertical motion acceleration feedback sensors that are integrated into a closed-loop wheelchair servo control system to differentially control the rotational speed of wheelchair opposed motor-driven wheels and thereby obtain improved wheelchair motion stability through reduction/elimination of likely wheelchair spin-out and wheelchair tipping during wheelchair operation.

Abstract: Systems and methods for controlling a device are disclosed. In one embodiment, the systems and methods allow for the control of a human transport device such that the human transport device remains in an upright position regardless of the surface being traversed. The systems and methods may include a plurality of operational modes where each mode has different characteristics. Additionally, systems and method for locating a center of gravity of a device are disclosed.

Abstract: A method for controlling a four-wheel steering system of a vehicle includes recognizing a driver-selectable mode, receiving a signal preferably indicative of a front wheel steering-angle, and determining a rear-to-front steering-angle ratio in correspondence with the recognized mode and the received signal; and optionally includes receiving a signal indicative of vehicle speed, recognizing a current system state, determining a desired steering-angle, generating a command based on the desired and received steering-angles and the recognized system state, and diagnosing conditions in accordance with the received signals in order to enter a output disable mode.

Abstract: The present invention provides a suspension for a conveyance that is capable of traversing obstacles and rough terrain. In this regard, the suspension has a frame member and a pivoting assembly. The pivoting assembly has a pivot arm and a drive assembly. The pivot arm is pivotally coupled to the frame and has a first engagement surface. The drive assembly is pivotally coupled to the frame and has a second engagement surface configured to engage the first engagement surface. The second engagement surface is further configured to disengage from the first engagement surface upon pivotal movement of the drive assembly in a first direction and to re-engage the first engagement surface upon pivotal movement of the drive assembly in a second direction.

Abstract: The invention concerns a drive unit for a tracked vehicle with a first and a second electric generator (6, 8) and with a first and a second internal combustion engine (10, 12), such that one generator (6, 8) can be driven respectively by one combustion engine (10, 12), and with electric drive motors (14, 16, 18, 20) for driving a right-hand and a left-hand drive track (4, 2). According to the invention it is proposed that the elements of the drive unit are linked in such manner that the right-hand drive track (4) is associated with first and second right-hand electric drive motors (14, 16), the left-hand drive track (2) is associated with first and second left-hand electric drive motors (18, 20), the two first drive motors (14, 18) being fed by the first generator (6) and the two second drive motors (16, 20) being fed by the second generator (8). Due to the wiring of the energy paths according to the invention, very great operational security is achieved even when the drive unit is partially damaged.

Abstract: The transformable vehicle comprises a central chassis assembly having first and second distal ends with an axis passing therebetween, a first wheel assembly mounted to the first distal end, and a second wheel assembly mounted to second distal end. A multifunction transformable vehicle comprising at least two configurational states: a stowed state and a transformed state. In the stowed state, the transformable vehicle comprises a compact structure suitable for storage, transport or deployment. During transition from the stowed state to the transformed state, the first and second wheel assemblies move longitudinally outward along the axis to reveal the central chassis assembly.

Abstract: A switch for use in a ride-on vehicle for children. The switch includes plural contact sets operated by an actuator to control the speed and/or direction of the vehicle. In the disclosed embodiment, a separator structure blocks contact sets from closing when they should be open to prevent inadvertent shorting.

Abstract: A robotic inspection system for gas turbine combustion components includes an exterior manipulator for visual inspection of the exterior surface of the impingement sleeve, an interior manipulator for visual inspection of the interior of the transition piece body and an annulus manipulator for inspecting the side weld seams of the transition piece body. The exterior manipulator includes an arcuate segment extending about the annular spaced impingement sleeves and a robotic subassembly including a linear rail and an upper arm and forearm mounting an inspection head pivotally coupled to one another for visual inspection of the top, bottom and side external surfaces of the impingement sleeve. The interior manipulator mounts to the open end of the combustion casing and includes an arm mounted for universal pivotal movement to the mount, actuators for pivoting the arm and motors for extending and rotating an inspection head about pan and tilt axes within the interior of the transition piece body.

Abstract: An apparatus for driving electrically a hand-operated wheelchair includes two driving devices, a power supply device, and a control device. Each driving device includes a motor unit provided with a motor shaft and a transmission unit that is adapted to be mounted removably on a respective one of the wheels of the wheelchair so as to transfer rotation of the motor shaft to the respective one of the wheels in such a manner that each of the wheels rotates at a speed smaller than that of the respective motor shaft. The power supply device is adapted to be disposed on a chair frame for supplying electrical power to the motor units. The control device controls speed ratios of the motor shafts of the motor units so as to be adapted to steer the wheelchair.

Abstract: An omnidirectional vehicle includes a body, and a plurality of units, each unit including a bearing rotatably supporting a steering shaft around a vertical axis with a rotor plate, and a driving wheel axially supported by a supporter fixed to the rotor plate. The driving wheel is positioned at a location spaced apart for a first offset distance from the steering shaft in the rolling direction of the driving wheel and spaced apart for a second offset distance from the steering shaft in the direction perpendicular to the rolling direction of the driving wheel. A first motor is fixed to the body for driving the steering shaft, and a second motor is fixed to the body for rotating the driving wheel. In the holonomic omnidirectional vehicle, the control system and the driving system are simplified, and interference therebetween is prevented. Also, it is possible to reduce the capacities of the actuators, the electric power for driving the vehicle and the manufacturing costs.

Abstract: A power unit for use with a motorized cart. Two wheels are rotatably mounted to opposite ends of an interconnecting member. In one embodiment, at least one driving motor is housed in at least one of these two wheels. In another embodiment, a driving motor is housed in one of the two wheels, and batteries are housed in the other wheel. In a further embodiment, two opposite platforms are mounted over the interconnecting member in a spaced relation to each other. In yet another embodiment, a battery-accommodating portion is disposed between the two platforms. Batteries are housed in the battery-accommodating portion. Where the cart is a golf cart, the motor and the batteries are concealed from view in every embodiment of the invention. This is favorable from an aesthetical point of view. Furthermore, the space in at least one wheel can be effectively utilized. Where the frame of the golf cart is foldable, it is easy to store and transport the cart.

Abstract: A motorized walker/wheelchair having wheels, an A-frame which has a driven a leg and a rolling leg which join at a vertex. Rising from one of the legs there is a control handle assembly. A motor wheel, or optionally two motor wheels, are provided at the lower portion of the driven leg of the A-frame. A caster wheel extends from the bottom of the rolling leg. Provision is made for a seat which is secured at its rearward portion to the seat support spreader. Hand controls are provided to the handle support which in turn control the operation of at least one motor driven wheel, or optionally, to separate motors driving two wheels. The two legs, the driven leg and a rolling leg, are joined at a pivot point at their vertex.

Abstract: Motorized chassis, base, cart and/or carriage apparatus and methods for supporting mobile medical imaging systems. Such apparatus having precision propulsion mechanism to mechanically guide, advance and retract medical imaging equipment about a body of a patient. The invention further including methods of manufacture and use thereof.

Abstract: An electric power assisted, manually operated vehicle such as a wheelchair. A force sensor senses the manual input force and the power assist is generated in response to the sensed input force. A number of embodiments are disclosed wherein the amount of assist is varied in response to running conditions and/or operator conditions so as to improve the performance. In many of these embodiments, the assist is greater at low speeds and is held constant at higher speeds and then decreased as the speed exceeds a predetermined high speed. In some of these embodiments, a regenerative braking is also applied in the event the vehicle speed becomes excessive. Also, the null or dead band range of the sensor is adjusted so as to provide a wider range when stationary than when running. This decreases sensitivity for startup and yet provides good response during running.

Abstract: With a vehicle comprising a motor (5) and at least one rotatable element (1, 2; 10) which follows the ground, at least one rotatable element (1, 2; 10) is connected to a steering mechanism for controlling the direction of travel of the vehicle. The steering mechanism comprises means (11) for adjusting the momentary distance from the axis of rotation of at least a part of a rotatable element (1, 2; 1 0) to the ground or means for adjusting the momentary coefficient of friction of at least a part of a rotatable element (1, 2; 10). Thus, the vehicle has a simple steering mechanism.

Abstract: A motorized wheelchair is advantageously provided with a rate-of-turn feedback sensor and with forward/reverse motion, lateral motion, and vertical motion acceleration feedback sensors that are integrated into a closed-loop wheelchair servo control system to differentially control the rotational speed of wheelchair opposed motor-driven wheels and thereby obtain improved wheelchair motion stability through reduction/elimination of likely wheelchair spin-out and wheelchair tipping during wheelchair operation.

Abstract: A central drive personal mobility vehicle is disclosed comprising a frame having a right and a left frame mounting located in a trailing frame portion of the frame with a seat being mounted to an intermediate portion of the frame. A right and a left leaf spring extend between a proximal end and a distal end. The proximal ends of the right and left leaf springs are secured to a right and a left drive wheel assembly supporting a left and a right drive wheel. The distal ends of the right and left leaf springs are secured to the right and left frame mounting for resiliently mounting the right and left drive wheel assemblies to the frame.

Abstract: The invention is a multifunctional, mobile appliance capable of performing a variety of tasks safely, quietly, without pollution, and out of sight of its owner. Such tasks might include lawn mowing, fertilizing, and edging, floor vacuuming, waxing, and polishing, or rug shampooing. In its preferred implementation, the mobile unit 1 would obtain precise real time and position information using the Real Time Kinematic Global Positioning System. The user initially guides the appliance around the work-area perimeters. The device then uses this information to determine the full working area. Proximity detectors and impact sensors help the appliance avoid unexpected obstacles. The device is quiet enough to perform its task in the middle of the night while its owner is asleep, but can be programmed to work continuously or during any user-specified time interval. The small turning radius of the appliance allows it to follow intricate perimeters.