RF only guidance system

A programmable utility vehicle assembly 10 comprising:

• a carriage 20 for moving over a plot,
• a mobile transceiver 30 attached to said carriage 20 for transmitting a signal,
• a power unit 22 for driving said carriage 20 over the plot,
• a steering unit 24 for steering said carriage 20 over the plot,
• a plurality of locating stations 40 each having a stationary transceiver 42 for receiving a signal from said mobile transceiver 30 and transmitting a return signal to said mobile transceiver 30,
• a central processing unit 60 (CPU) on said carriage 20 for preprogramming a desired carriage 20 path having a counter 62 for counting two way propagation time between said mobile transceiver 30 and said remote locating stations 40 to determine said carriage 20 location and guide said carriage 20 along the programmed path,
• said CPU 60 including a memory circuit 75 for storing data points
• each data point including said timing pulse two way propagation time between said mobile transceiver 30 and said remote locating stations 40 and a direct indicating said carriage 20 direction.

A programmable utility vehicle assembly 10 comprising:

• a carriage 20 for moving over a plot,
• a mobile transceiver 30 attached to said carriage 20 for transmitting a signal,
• a power unit 22 for driving said carriage 20 over the plot,
• a steering unit 24 for steering said carriage 20 over the plot,
• a plurality of locating stations 40 each having a stationary transceiver 42 for receiving a signal from said mobile transceiver 30 and transmitting a return signal to said mobile transceiver 30,
• a central processing unit 60 (CPU) on said carriage 20 for preprogramming a desired carriage 20 path having a counter 62 for counting two way propagation time between said mobile transceiver 30 and said remote locating stations 40 to determine said carriage 20 location and guide said carriage 20 along the programmed path,
• said carriage 20 including a keypad 90 connected to said CPU 60 for programming said CPU 60.

A method for programming a vehicle central processing unit 60 (CPU) on a carriage 20 for driving and directing the carriage 20 over a plot in response to instructions from the CPU 60, said method comprising the steps of:

• placing a plurality of remote locating stations 40 in spaced positions about a plot, and
• placing a mobile transceiver 30 on a carriage 20, and
• transmitting a first signal from the mobile transceiver 30 to the locating stations 40, and
• returning a return signal to the mobile transceiver 30 from the locating stations 40, and
• counting the two way propagation time of the first and return signals between the mobile transceiver 30 and the locating stations 40 for determining the carriage 20 location,
• transmitting a radio frequency timing pulse,
• transmitting separate coded timing pulses to said locating stations 40 wherein each locating station 40 includes a code interpreting circuit 71 for receiving and a code generating circuit 70 for retransmitting said separate coded signals to said mobile transceiver 30,
• delaying the return transmission to said mobile transceiver 30 from said locating stations 40, and
• storing data points comprising two way propagation time between the mobile transceiver 30 and the locating towers while maneuvering the carriage 20 along a desired route.

A method for programming a vehicle central processing unit 60 (CPU) on a carriage 20 for driving and directing the carriage 20 over a plot in response to instructions from the CPU 60, said method comprising the steps of:

• placing a plurality of remote locating stations 40 in spaced positions about a plot,
• placing a mobile transceiver 30 on a carriage 20,
• transmitting a first signal from the mobile transceiver 30 to the locating stations 40,
• returning a return signal to the mobile transceiver 30 from the locating stations 40,
• counting the two way propagation time of the first and return signals between the mobile transceiver 30 and the locating stations 40 for determining the carriage 20 location, setting predetermined times in the CPU 60 for the carriage 20 to automatically follow the programmed path.