SAFE AND LOW COST COMPUTER PERIPHERALS WITH FORCE FEEDBACK FOR CONSUMER APPLICATIONS
Power management for an interface device that is manipulated by a user and in communication with a host computer and provides forces to the user. The device includes a sensor and an actuator. One embodiment provides first power from the host computer over a serial interface and second power from a power adapter. Another embodiment provides first power from the host computer and second power from a power storage device on the interface device that supplies power to the actuator. Another embodiment provides a power adapter supplying a portion of the first power to the sensor and a portion to the actuator, and a power storage device on the interface device provides second power to the actuator.
1 . An interface apparatus for interfacing motion of a user manipulable object with a host computer and enabling said host computer to track motion of said user manipulable object and to command feedback forces to said user manipulable object, said interface apparatus comprising:
a user object being physically contacted and manipulable by a user and having at least one degree of freedom of movement with respect to a ground surface;
a device microprocessor provided local to said interface apparatus and separate from said host computer and being controlled by software instructions stored in a memory device separate from said host computer, said microprocessor being coupled to said host computer by a first interface bus and receiving host commands from said host computer on said first interface bus;
an actuator coupled to said user object for applying a force along said degree of freedom to said user object, wherein said actuator applies said force in response to microprocessor force commands produced by said device microprocessor; and
a sensor coupled to said user object for detecting a position of said user object along said degree of freedom and for outputting a locative sensor signal which represents said position of said user manipulable object, said locative sensor signal being received by said host computer, wherein said host computer modifies a displayed process in response to said locative sensor signal.
2 . An interface apparatus as recited in claim 1 wherein said first interface bus is a serial interface bus for transmitting and receiving data serially.
3 . An interface apparatus as recited in claim 2 wherein said first interface bus is an RS-232 interface bus coupled to an RS-232 interface port of said host computer.
4 . An interface apparatus as recited in claim 3 wherein said user object includes a joystick.
5 . An interface apparatus as recited in claim 3 wherein said sensor is a first sensor and said locative sensor signal is a first locative sensor signal, and further comprising a second sensor coupled to said device microprocessor, wherein said first sensor outputs said first locative sensor signal to said host computer on said first interface bus, and wherein said second sensor detects said position of said joystick along said degree of freedom independently of said first sensor and outputs a second locative sensor signal to said microprocessor.
6 . An interface apparatus as recited in claim 5 further comprising a button device coupled to said interface apparatus, said button device providing a button input signal to said microprocessor when said user activates said button, said microprocessor providing said button input signal to said host computer using said game port interface bus.
7 . An interface apparatus as recited in claim 6 wherein said microprocessor, said first sensor, said second sensor, and said button are powered by said host computer using a power line of said RS-232 interface bus.
8 . A force feedback interface device as recited in claim 2 further comprising a power store circuit coupled to said actuator, said power store circuit storing power from a power source and providing said stored power to said actuator when said actuator applies said force to said user object, said power store circuit including a capacitor that charges to store said power and discharges said stored power for said actuator.
9 . An interface apparatus as recited in claim 4 wherein said microprocessor deactivates said actuator when said bus is disconnected from said host computer or disconnected from said interface apparatus.
10 . An interface apparatus as recited in claim 4 further comprising a safety switch for said user, wherein said actuator is operative to output said force only when said safety switch is closed.
11 . An interface apparatus as recited in claim 10 wherein said safety switch is a hand-weight safety switch coupled to said joystick, said hand weight safety switch being closed by said user when said user applies weight to said joystick by grasping said joystick.
12 . An interface apparatus as recited in claim 4 wherein said joystick includes a safety break-away handle that breaks off from said interface apparatus when a force over a predetermined threshold is applied to said joystick.
13 . An interface apparatus as recited in claim 5 further comprising a local memory device separate from said host computer, said local memory device storing at least one force routine, wherein said microprocessor selects a force routine in accordance with said at least one of said host commands, said force routine determining said microprocessor force commands, at least in part, from said sensor signals of said microprocessor sensors.
14 . An interface apparatus as recited in claim 1 wherein said selected force routine retrieves a plurality of digital force values stored in said local memory device and outputs said stored force values to said actuator.
15 . An interface apparatus for interfacing motion of a user manipulable joystick with a host computer, said interface apparatus comprising:
a joystick being physically contacted by a user and having at least one degree of freedom of movement;
an actuator coupled to said joystick for applying a force along said degree of freedom to said joystick; wherein said actuator applies said force in response to force commands received from said host computer via a first interface bus coupling said interface apparatus to a first interface port of said host computer; and
a sensor for detecting a position of said joystick along said degree of freedom and outputting sensor signals, said sensor signals being received by said host computer.
16 . An interface apparatus as recited in claim 15 wherein said first interface port is an RS-232 port.
17 . An interface apparatus as recited in claim 15 wherein said force commands received by said actuator are host data sent by said host computer and which instruct said actuator to output said force in accordance with a software process running on said host computer.
18 . An interface apparatus as recited in claim 17 wherein said first interface bus transmits said host data serially to said interface apparatus from said host computer, and further comprising at least one shift register for providing said serial host data as control signals to said actuator.
19 . An interface apparatus as recited in claim 17 further comprising a programmable logic device for receiving said control signals from said at least one shift register and controlling said force from said actuator using said control signals.
20 . An interface apparatus as recited in claim 18 wherein said interface bus transmits at least a portion of said host data in parallel in conjunction with said serially transmitted host data.
21 . An interface apparatus as recited in claim 18 wherein said interface bus is an RS-232 interface bus in which two lines are used to transmit data to said interface apparatus as parallel information and in which one line is used to transmit data to said interface apparatus as serial information.
22 . An interface apparatus as recited in claim 18 wherein said interface bus is an RS-232 interface bus in which all lines included in said RS-232 bus are used to transmit data to said interface apparatus as parallel information.
23 . An interface apparatus as recited in claim 20 wherein said actuator is a motor and said sensor is an analog potentiometer.
24 . An interface apparatus as recited in claim 17 further comprising a button device coupled to said interface apparatus, said button device providing a button input signal to said host computer via a second serial interface bus when said user activates said button.
25 . An interface apparatus as recited in claim 18 wherein said actuator is deactivated when at least one of said first and second interface buses is disconnected from said host computer or disconnected from said interface apparatus.
26 . An interface device as recited in claim 15 further comprising a device microprocessor provided local to said interface apparatus and separate from said host computer, said microprocessor being coupled to said host computer by said first serial interface bus, wherein said microprocessor receives host commands from said host computer on said first serial interface bus and provides processor host commands to said actuator to command said actuator to apply said force to said joystick.
27 . An interface apparatus as recited in claim 15 further comprising a hand-weight safety switch for said user and coupled to said joystick, wherein said actuator is operative to output said force only when said safety switch is closed, said hand weight safety switch being closed by said user when said user applies weight to said joystick by grasping said joystick.
28 . An interface apparatus as recited in claim 15 further comprising an optical safety switch for said user and coupled to said joystick, wherein said actuator is operative to output said force only when said safety switch is closed, said optical safety switch being closed by said user when said user blocks an optical sensor of said optical safety switch by contacting said joystick.