A system for monitoring and controlling shopping cart usage comprises a wheel assembly that attaches to a shopping cart. The wheel assembly includes a wheel, a brake that can be activated to inhibit rotation of the wheel, a controller that controls the brake, a VLF receiver, and an RF transceiver. The RF transceiver may, for example, operate in a 2.4 GHz frequency band. In some implementations, the RF transceiver may be used to detect entry of the shopping cart into a checkout area of the store, and the VLF receiver may be used to detect that the shopping cart is exiting the store. The controller may activate the brake if the shopping cart attempts to exit the store without first passing through a checkout area.

A motorized cart retriever, which may be a cart pusher or a cart puller, can apply a force to a nest of human-propelled, wheeled carts to facilitate retrieval of the carts. The cart retriever can include a transceiver configured to wirelessly receive cart status information from cart transmitters of the wheeled carts and wirelessly report event data to a control unit. The cart status information may include an identification of the cart transmitter, a location of the cart, a lock or unlock status of a cart wheel, a misuse condition, etc. The event data can include the cart status information, a number of wheeled carts being retrieved, etc. The cart wheel may include a brake. The transceiver may communicate a message to the cart wheel to keep the brake unactuated during retrieval. The control unit may analyze the event data to detect traffic patterns of the carts.

An integrated circuit chip (2), an antenna (3) and a tamper loop (4), and in addition to this, a light emitting diode (LED) (20), configured to be activated, i.e. supplied with current, upon a signal received by the antenna (3). The LED (20) is integrated in the device in such a way that when the LED is activated in the above-described way, the LED lights up so as to become visible by the naked eye, on the condition that the tamper loop (4) is in a predefined state, either open or closed. The LED (20) is coupled between the same terminals (8,9) of the integrated circuit chip (2) as the tamper loop (4).

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.

An integrated circuit chip (2), an antenna (3) and a tamper loop (4), and in addition to this, a light emitting diode (LED) (20), configured to be activated, i.e. supplied with current, upon a signal received by the antenna (3). The LED (20) is integrated in the device in such a way that when the LED is activated in the above-described way, the LED lights up so as to become visible by the naked eye, on the condition that the tamper loop (4) is in a predefined state, either open or closed. The LED (20) is coupled between the same terminals (8,9) of the integrated circuit chip (2) as the tamper loop (4).

A motorized cart retriever, which may be a cart pusher or a cart puller, can apply a force to a nest of human-propelled, wheeled carts to facilitate retrieval of the carts. The cart retriever can include a transceiver configured to wirelessly receive cart status information from cart transmitters of the wheeled carts and wirelessly report event data to a control unit. The cart status information may include an identification of the cart transmitter, a location of the cart, a lock or unlock status of a cart wheel, a misuse condition, etc. The event data can include the cart status information, a number of wheeled carts being retrieved, etc. The cart wheel may include a brake. The transceiver may communicate a message to the cart wheel to keep the brake unactuated during retrieval. The control unit may analyze the event data to detect traffic patterns of the carts.

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.

In an embodiment, a method of managing an output power delivered by an antenna of a NFC apparatus includes: providing a matching circuit with a first tuning capacitive network coupled in series between a NFC controller and the antenna and with a second tuning capacitive network coupled to the NFC controller and the antenna and to a reference terminal, wherein the first or second tuning capacitive network has a variable capacitive value; determining tuning capacitive values of the first tuning capacitive networks to adjust a delivered output power at a desired level; and setting the tuning capacitive values of the first tuning capacitive network to the tuning capacitive values.

A system for monitoring and controlling shopping cart usage comprises a wheel assembly that attaches to a shopping cart. In some embodiments the wheel assembly includes a wheel, a brake that can be activated to inhibit rotation of the wheel, a controller that controls the brake, a VLF receiver, and an RF transceiver. The RF transceiver may, for example, operate in a 2.4 GHz frequency band. In some implementations, the RF transceiver may be used to detect entry of the shopping cart into a checkout area of the store, and the VLF receiver may be used to detect that the shopping cart is exiting the store. The controller may activate the brake if the shopping cart attempts to exit the store without first passing through a checkout area.

A motorized cart retriever, which may be a cart pusher or a cart puller, can apply a force to a nest of human-propelled, wheeled carts to facilitate retrieval of the carts. The cart retriever can include a transceiver configured to wirelessly receive cart status information from cart transmitters of the wheeled carts and wirelessly report event data to a control unit. The cart status information may include an identification of the cart transmitter, a location of the cart, a lock or unlock status of a cart wheel, a misuse condition, etc. The event data can include the cart status information, a number of wheeled carts being retrieved, etc. The cart wheel may include a brake. The transceiver may communicate a message to the cart wheel to keep the brake unactuated during retrieval. The control unit may analyze the event data to detect traffic patterns of the carts.