A navigation system uses a dead reckoning method to estimate an object's present position relative to one or more prior positions. In some embodiments, the dead reckoning method determines a change in position from the object's heading and speed during an elapsed time interval. In embodiments suitable for use with wheeled objects, the dead reckoning method determines the change in position by measuring the heading and the amount of wheel rotation. Some or all of the components of the navigation system may be disposed within a wheel, such as a wheel of a shopping cart.

A utility handcart can include foldable struts to reduce an overall volumetric footprint of the handcart. The struts can be selectively rotated with a pin to fix the struts in either a stowed position or a downward position for supporting wheels during use. The utility handcart can also include an uphill assist mechanism securing the wheels to the struts or engaged with the wheel axles to prevent the wheels from rotating in one direction, for example backward, when parked or pulled up a hill. The uphill assist mechanism can be selectively engaged to either allow for rotation of the wheels in both directions or prevent the backward rotation of the wheels as desired by the user.

A vehicle tracking system includes a wheel assembly containing sensor circuitry capable of sensing various types of conditions, such as specific electromagnetic and/or magnetic signals indicative of particular wheel locations. The sensor circuitry is coupled to an RF transceiver, which may but need not be included within the wheel. The wheel may also include a brake mechanism. In one embodiment, the wheels are placed on shopping carts and are used to collect and monitor shopping cart status and location data via a wireless network. In some embodiments, the wheel assemblies detect that they have entered into particular zones by measuring received signal strengths of received command transmissions, and by comparing these measurements to thresholds that are used to define zone boundaries.

A system is disclosed for tracking and controlling shopping carts and other types of human propelled vehicles. The system includes a wheel assembly that attaches to a cart. The wheel assembly includes a brake unit for inhibiting cart motion, and includes wireless communication circuitry. The wheel assembly is capable of activating the brake unit in response to one or more conditions, such as the receipt of an RF signal or command. In some embodiments, the system also includes a display unit that displays information to a user of the cart, including information regarding the cart's proximity to a lock zone in which the brake unit will become activated.

A vehicle tracking system includes a wheel containing sensor circuitry capable of sensing various types of conditions, such as wheel rotation, wheel vibration caused by skidding, and specific electromagnetic and/or magnetic signals indicative of particular wheel locations. The sensor circuitry is coupled to an RF transceiver, which may but need not be included within the wheel. The wheel may also include a brake mechanism. In one embodiment, the wheels are placed on shopping carts and are used to collect and monitor shopping cart status and location data via a wireless network. The collected data may be used for various purposes, such as locking the wheel of an exiting cart if the customer has not paid, estimating numbers of queued carts, stopping wheel skid events that occur during mechanized cart retrieval, store planning, and providing location-based messaging to customers.

Brake mechanisms for a wheel of non-motorized wheeled vehicle such as, e.g., a shopping cart, are described. In various embodiments, the brake mechanism can provide a variable amount of braking force or torque between zero and an amount sufficient to lock the wheel. In some embodiments, the brake mechanism includes a brake plate that is movable toward and away from a surface of the wheel hub along a direction parallel to the rotation axis of the wheel. The brake plate is configured not to rotate when the wheel and hub are rotating. Frictional engagement between the brake plate and the surface of the wheel hub provides the braking force. The brake plate and/or the surface of the wheel hub can include engagement features such as, e.g., protrusions and slots. In some embodiments, the brake mechanism fits entirely within the wheel.

Various systems for detecting unauthorized exit events are disclosed. The systems can support a variety of different methods for assessing whether a customer is exiting the store without paying. The particular method or methods used may vary widely based on the types and the locations of the system components included in a given installation. For example, the system may be configured to detect that a cart has passed or is passing through a checkout lane.

A navigation system uses a dead reckoning method to estimate an object's present position relative to one or more prior positions. In some embodiments, the dead reckoning method determines a change in position from the object's heading and speed during an elapsed time interval. In embodiments suitable for use with wheeled objects, the dead reckoning method determines the change in position by measuring the heading and the amount of wheel rotation. Some or all of the components of the navigation system may be disposed within a wheel, such as a wheel of a shopping cart.

A power generation system for wheeled objects comprises a generator mechanically coupled to one or more of the object's wheels to convert wheel rotational energy into electrical energy. The power generation system may comprise an electrical storage device configured to store the electrical power produced by the generator. Power from the generator and/or the electrical storage device can be used to provide power to other electrical systems in or on the object. In certain embodiments, the electrical storage device comprises a bank of high-capacity capacitors connected in series. Some embodiments use a control circuit, for example, to regulate the charging and discharging of the capacitor bank and to provide suitable voltages for other systems. The power generation system may be disposed within an object's wheel, such as a wheel of a shopping cart.

The foldable cart has a pulling rod assembly, a foldable cart frame, a plurality of wheels and a storage bag. The foldable cart frame has a front frame, a rear frame, two foldable fence assemblies and a foldable bottom supporting assembly. A front connecting bar is connected to a bottom of the front frame, and a bottom end of the pulling rod assembly is rotatably connected to a middle portion of the front connecting bar. The number of the wheels is four, two wheels are a pair of front universal wheels and two wheels are a pair of rear directional wheels, the two front universal wheels detachably connect to the front connecting bar; the rear frame has a pair of mounting blocks disposed on a bottom of the rear frame, and each rear directional wheel detachably connects to a corresponding mounting block.