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US 7,353,089 B1Granted
Method and system for a signal guided motorized vehicle
AssigneePEM Technologies, Inc.
InventorPaul E. McEvoy
Life of this patent
Estimating the term…
Abstract
A motorized cart that supports one or more golf bags automatically follows a golfer around the golf course from hole to hole. In particular, the golfer wears, or carries, a signal transmitter that emits a signal that is received by the motorized cart and then used by the motorized cart to stay within a predetermined range of the golfer. In addition to golfers, delivery personnel and other users may also benefit from this cart.
Claims18
A motorized cart controlled by a radio frequency signal comprising:
- a receiver configured to detect a signal emitted from a transmitter;
- a signal processor, in communication with the receiver, configured to determine a relative position of the transmitter based on a phase difference between the signal received on a first antenna and the signal received on a second antenna, and to generate first and second drive control signals from the signals received on the first and second antennas;
- and
- motor control circuitry, in communication with the signal processor, configured to drive a first drive motor based on the first drive control signal and drive a second drive motor based on the second drive control signal so as to move a location of the motorized cart,
- wherein the motorized cart maintains a predetermined distance from the transmitter, and
- further wherein the first and second drive control signals prevent the first and second drive motors from moving the cart when the cart is within a predetermined distance from the transmitter.
3 more elements
A method of controlling a driverless, motorized cart, comprising the steps of:
- receiving a radio-frequency signal at the cart on a first antenna and a second antenna from a transmitter;
- determining a location of the transmitter from the received radio-frequency signal;
- calculating a left/right direction of the cart in relation to the transmitter from a phase difference between the radio-frequency signal received on a first antenna and the radio-frequency signal received on a second antenna;
- calculating a distance between the location of the transmitter and a location of the cart from an amplitude of the received radio-frequency signal on the first and second antennas;
- comparing the distance to a predetermined value;
- in response to the distance being greater than the predetermined value, generating first and second drive control signals from the distance and left/right direction that respectively and independently control a first and a second drive motor causing movement of the cart toward the transmitter so as to maintain a predetermined distance from the transmitter;
- and
- in response to the distance being within the predetermined value, generating first and second drive control signals that prevent the first and second drive motors from moving the cart.
5 more elements
A motorized golf cart system comprising:
- a transmitter configured to emit a modulated signal;
- a receiver configured to detect the modulated signal;
- a signal processor, in communication with the receiver, configured to determine a relative position of the transmitter based on a phase difference between the modulated signal received on a first antenna and the modulated signal received on a second antenna, and generate first and second drive control signals from the modulated signals received on the first and second antennas;
- and
- motor control circuitry, in communication with the signal processor, configured to drive a first drive motor based on the first drive control signal and drive a second drive motor based on the second drive control signal so as to move a location of the motorized cart,
- wherein the motorized cart maintains a predetermined distance from the transmitter, and
- further wherein the first and second drive control signals prevent the first and second drive motors from moving when the cart is within a predetermined distance of the transmitter.
4 more elements
A motorized cart system comprising:
- a transmitter configured to emit a modulated signal;
- a receiver including a first antenna coupled to a first side of the cart and a second antenna coupled to an opposing second side of the cart, the receiver configured to detect the modulated signal;
- a signal processor, in communication with the receiver, configured to determine a relative position of the transmitter based on a phase difference between the modulated signal received on the first antenna and the modulated signal received on the second antenna, and generate first and second drive control signals from the modulated signals received on the first and second antennas;
- motor control circuitry, in communication with the signal processor, configured to drive a first drive motor based on the first drive control signal and drive a second drive motor based on the second drive control signal so as to move a location of the motorized cart, the signal processor further configured to monitor respective current draw from the first drive motor and the second drive motor and adjust a torque of the first and second drive motors in response to the monitored current draw;
- a battery charge circuit coupled with a power source of the motorized golf cart;
- and
- a port of the battery charge circuit configured to receive the transmitter and recharge a transmitter power source,
- wherein the motorized cart maintains a predetermined distance from the transmitter, and
- wherein the first and second drive control signals prevent the first and second drive motors from moving when the cart is within a predetermined distance of the transmitter, and
- wherein the battery charge circuit switches to a maintenance state when the transmitter power source is fully recharged to avoid overcharging.
7 more elements
Dependencies are inferred from the claim text.