# US 8,571,778 B2 · Cart braking control during mechanized cart retrieval > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,571,778 B2 - Document ID: US8571778B2 - Status: Granted - Kind: B2 - Application number: 13/850,220 - Filed: 2013-03-25 - Published: 2013-08-22 - Granted: 2013-10-29 - Earliest claimed: 2005-03-18 - Assignees: Gatekeeper Systems, Inc. - Applicants: Gatekeeper Systems, Inc. - Inventors: Stephen E. Hannah; Scott J. Carter; Jesse M. James - Web page: https://patentgrep.com/patent/US8571778B2 ## CPC - B62B 5/0438: {hand operated} - H04W 4/02: Services making use of location information - A47F 10/04: for storing or handling self-service hand-carts or baskets - B60K 25/08: from a ground wheel, e.g. engaging the wheel tread or rim - B60T 7/16: operated by remote control, i.e. initiating means not mounted on vehicle - B60T 7/18: operated by wayside apparatus - B62B 3/14: characterised by provisions for nesting or stacking, e.g. shopping trolleys {(collapsible shopping trolleys B62B3/027)} - B62B 3/1404: {Means for facilitating stowing or transporting of the trolleys; Antitheft arrangements (B62B5/0423 takes precedence)} - B62B 3/1412: {mounted on the frame} - B62B 3/1424: {Electronic display devices} - B62B 3/1492: {Wheel arrangements} - B62B 5/0003: {Adaptations for loading in or on a vehicle} - B62B 5/0423: {braking or blocking when leaving a particular area} - B62B 5/048: {Hub brakes; drum brakes} - G01C 21/12: executed aboard the object being navigated; Dead reckoning - G01C 21/206: {specially adapted for indoor navigation} - G06K 7/10366: {the interrogation device being adapted for miscellaneous applications} - G06Q 10/08: Logistics, e.g. warehousing, loading or distribution; Inventory or stock management - G08B 13/2434: {Tag housing and attachment details} - G08B 13/2448: {Tag with at least dual detection means, e.g. combined inductive and ferromagnetic tags, dual frequencies within a single technology, tampering detection or signalling means on the tag} - G08B 13/2462: {Asset location systems combined with EAS (inventory, tracking, logistic G06Q10/00; entrance control systems G07C9/00)} - G08B 13/2482: {EAS methods, e.g. description of flow chart of the detection procedure} - G08G 1/20: {Monitoring the location of vehicles belonging to a group, e.g. fleet of vehicles, countable or determined number of vehicles} - H02K 7/1846: {structurally associated with wheels or associated parts (dynamos arranged in the wheel hub of cycles B62J6/12)} - H04W 4/024: Guidance services - H04W 4/029: Location-based management or tracking services - G08B 13/246: {Check out systems combined with EAS, e.g. price information stored on EAS tag (anti-theft systems in point of sale systems G07G3/003)} - G08B 13/2474: {Antenna or antenna activator geometry, arrangement or layout (loop antennae H01Q1/22)} - G08B 13/2477: {Antenna or antenna activator circuit} - Y10T 29/49826: Assembling or joining - B62B: HAND-PROPELLED VEHICLES, e.g. HAND CARTS OR PERAMBULATORS; SLEDGES (characterised by animal propulsion B62C; propulsion of sledges by driver or engine B62M) - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) - A47F: SPECIAL FURNITURE, FITTINGS, OR ACCESSORIES FOR SHOPS, STOREHOUSES, BARS, RESTAURANTS OR THE LIKE; PAYING COUNTERS - B60K: ARRANGEMENT OR MOUNTING OF PROPULSION UNITS OR OF TRANSMISSIONS IN VEHICLES; ARRANGEMENT OR MOUNTING OF PLURAL DIVERSE PRIME-MOVERS IN VEHICLES; AUXILIARY DRIVES FOR VEHICLES; INSTRUMENTATION OR DASHBOARDS FOR VEHICLES; ARRANGEMENTS IN CONNECTION WITH COOLING, AIR INTAKE, GAS EXHAUST OR FUEL SUPPLY OF PROPULSION UNITS IN VEHICLES - B60T: VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL (electrodynamic brake systems for vehicle, in general B60L; brakes per se, i.e. devices where braking effect occurs, including ultimate brake actuators, F16D); ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES - G01C: MEASURING DISTANCES, LEVELS OR BEARINGS; SURVEYING; NAVIGATION; GYROSCOPIC INSTRUMENTS; PHOTOGRAMMETRY OR VIDEOGRAMMETRY (measuring liquid level G01F; radio navigation, determining distance or velocity by use of propagation effects, e.g. Doppler effects, propagation time, of radio waves, analogous arrangements using other waves G01S) - G06K: GRAPHICAL DATA READING (image or video recognition or understanding G06V); PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS - G06Q: INFORMATION AND COMMUNICATION TECHNOLOGY [ICT] SPECIALLY ADAPTED FOR ADMINISTRATIVE, COMMERCIAL, FINANCIAL, MANAGERIAL OR SUPERVISORY PURPOSES; SYSTEMS OR METHODS SPECIALLY ADAPTED FOR ADMINISTRATIVE, COMMERCIAL, FINANCIAL, MANAGERIAL OR SUPERVISORY PURPOSES, NOT OTHERWISE PROVIDED FOR - G08B: SIGNALLING SYSTEMS, e.g. PERSONAL CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS - G08G: TRAFFIC CONTROL SYSTEMS (guiding railway traffic, ensuring the safety of railway traffic B61L; arrangement of road signs or traffic signals E01F9/00; radar or analogous systems, sonar systems, lidar systems specially adapted for traffic control G01S13/91, G01S15/88, G01S17/88; {radar or analogous systems, sonar systems, lidar systems specially adapted for anti-collision purposes G01S13/93, G01S15/93, G01S17/93}) - H02K: DYNAMO-ELECTRIC MACHINES (dynamo-electric relays H01H53/00; conversion of DC or AC input power into surge output power {H03K3/53}) - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract A vehicle tracking system includes a wheel 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. 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, and stopping brake activation events from occurring during mechanized cart retrieval. ## Claims ### Claim 1 A system for controlling usage of shopping carts, comprising: a shopping cart wheel assembly that attaches to a shopping cart, the shopping cart wheel assembly having a wheel, a braking unit that inhibits movement of the shopping cart when activated, and a control unit that controls the braking unit, the control unit comprising communication circuitry configured to detect transmissions of a boundary signal, wherein the control unit is configured to respond to the boundary signal by conditionally activating the braking unit; a first transmitter positioned at a fixed location associated with a boundary, the first transmitter configured to transmit the boundary signal; and a second transmitter associated with a mechanized cart retrieval unit, the second transmitter configured to transmit a brake deactivation signal during mechanized cart retrieval, said second transmitter configured to transmit the brake deactivation signal in response to initiation by a retrieval unit operator of a cart retrieval operation; wherein the control unit is responsive to receiving the brake deactivation signal by maintaining the brake unit deactivated regardless of whether the boundary signal is detected, such that the brake unit remains deactivated during mechanized cart retrieval regardless of whether the shopping cart crosses the boundary. ### Claim 2 (depends on 1) The system of claim 1, wherein the control unit is configured to detect the boundary signal in a first frequency band, and to detect the brake deactivation signal in a second frequency band. ### Claim 3 (depends on 1) The system of claim 1, wherein the communication circuitry comprises a radio frequency transceiver configured to detect the brake deactivation signal. ### Claim 4 (depends on 3) The system of claim 3, wherein the communication circuitry further comprises a Very Low Frequency (VLF) receiver configured to detect the boundary signal. ### Claim 5 (depends on 1) The system of claim 1, wherein the second transmitter is mounted to the mechanized cart retrieval unit. ### Claim 6 (depends on 1) The system of claim 1, wherein the second transmitter includes a directional antenna positioned to focus transmissions on shopping carts being retrieved by the mechanized cart retrieval unit. ### Claim 7 (depends on 1) The system of claim 1, wherein the deactivation signal comprises a command that is addressed to particular shopping carts that are identified as being part of a shopping cart nest. ### Claim 8 (depends on 1) The system of claim 1, wherein the shopping cart wheel assemblies are configured to generate RSSI values based on received transmissions of the brake deactivation signal, and to use the RSSI values do determine whether to maintain their respective brake units deactivated. ### Claim 9 A cart wheel assembly configured to be attached to a shopping cart, the cart wheel assembly comprising: a wheel; a braking unit configured to inhibit movement of the shopping cart when the braking unit is activated; and a control unit comprising a controller connected to communication circuitry, the control unit configured to detect a boundary signal transmitted in a first frequency band, and to detect a brake deactivation signal transmitted in a second frequency band, said brake deactivation signal transmitted in response to initiation of a cart retrieval operation by an operator of a mechanized cart retrieval unit, wherein the control unit is configured to (a) activate the braking unit in response to detecting the boundary signal if the brake deactivation signal is not detected, and (b) maintain the braking unit in a deactivated state if the brake deactivation signal is detected regardless of whether the boundary signal is detected. ### Claim 10 (depends on 9) The cart wheel assembly of claim 9, wherein the communication circuitry comprises a radio frequency transceiver configured to detect the brake deactivation signal. ### Claim 11 (depends on 10) The cart wheel assembly of claim 10, wherein the communication circuitry further comprises a Very Low Frequency (VLF) receiver configured to detect the boundary signal. ### Claim 12 (depends on 9) The cart wheel assembly of claim 9, in combination with a transmitter that transmits the brake deactivation signal to the control unit when the shopping cart is being retrieved by the mechanized cart retrieval unit, such that the brake unit remains deactivated during mechanized retrieval of the shopping cart. ### Claim 13 (depends on 12) The cart wheel assembly and transmitter device of claim 12, wherein the transmitter transmits the brake deactivation signal from a directional antenna. ### Claim 14 (depends on 9) The cart wheel assembly of claim 9, in combination with the mechanized cart retrieval unit, wherein the mechanized cart retrieval unit transmits the brake deactivation signal during mechanized cart retrieval. ### Claim 15 (depends on 9) The cart wheel assembly of claim 9, wherein the control unit is configured to disregard the brake deactivation signal when a received signal strength measurement of the brake deactivation signal falls below a defined threshold. ### Claim 16 A method of controlling shopping cart usage, comprising: attaching a wheel assembly to a shopping cart, the wheel assembly comprising a braking unit and a control unit that controls the braking unit, the control unit configured to conditionally activate the braking unit in response to detecting a boundary signal; and during mechanized retrieval of the shopping cart with a mechanized cart retrieval unit, transmitting, from a transmitter associated with the mechanized cart retrieval unit, a signal that causes the wheel assembly to maintain the braking unit deactivated regardless of whether the boundary signal is detected, said signal transmitted automatically in response to initiation by a retrieval unit operator of a mechanized cart retrieval operation. ### Claim 17 (depends on 16) The method of claim 16, wherein the signal comprises a command that is addressed to particular wheel assemblies identified as being part of a nest of shopping carts.