Magnetic lock with throwable robot
A two wheeled throwable robot comprises an elongate chassis with two ends, a motor at each end, drive wheels connected to the motors, and a tail extending from the elongate chassis. The throwable robot includes an enable/disable arrangement comprising a pair of magnets generating a magnetic field and a magnetic field sensor positioned in proximity to the pair of magnets. The sensor is activated upon the occurrence of a specific modification of the magnetic field. The throwable robot may include a key member formed of a material to modify the magnetic field to enable the robot.
1. A throwable remotely controlled robot weighing less than six pounds comprising:
a housing having a holding portion defining a key holding slot;
a magnet disposed inside the housing, the magnet generating a first magnetic field;
a sensor disposed inside the housing, the sensor providing a first output signal when the first-magnetic field is present and a second output signal when a second magnetic field is present; and
a key member having shape conforming to the key holding slot, wherein the key member is formed of a material to modify the magnetic field from the first magnetic field to the second magnetic field.
2. The throwable remotely controlled robot of claim 1 , wherein the presence of the key member in the key holding slot alters an angle of flux lines in the magnetic field produced by the magnet at the sensor, the flux lines in the magnetic field produced by the magnet having a first angle at the sensor when the key member is present in the key holding slot and a second angle at the sensor when the key member is absent from the key holding slot.
3. The throwable remotely controlled robot of claim 1 , wherein the sensor comprises a Hall effect sensor.
4. The throwable remotely controlled robot of claim 1 , wherein the key member is configured as a plate.
5. The throwable remotely controlled robot of claim 1 , wherein the key member is made of steel.
6. The throwable remotely controlled robot of claim 1 , wherein the key member is retained within the housing by a magnetic force.
7. A throwable remotely controlled robot weighing less than six pounds with a housing comprising a magnet generating a magnetic field, and a sensor positioned in proximity to the magnetic field, the sensor requiring a specific modification of the magnetic field to actuate the sensor from providing a first output signal to providing a second output signal, and further comprising a key plate formed of a material to modify the magnetic field to enable the robot, the key plate conforming to a key holding slot in the housing.
8. The throwable robot of claim 7 , wherein the key plate is retained within the housing by a magnetic force.
9. The throwable remotely controlled robot of claim 7 , wherein the specific modification of the magnetic field is an increased vertical component of the magnetic field as measured by the sensor.
10. The throwable remotely controlled robot of claim 7 , wherein the specific modification of the magnetic field is an alteration of an angle of flux lines in the magnetic field.
11. The throwable remotely controlled robot of claim 7 , wherein actuating the sensor enables or disables the robot.
12. The throwable remotely controlled robot of claim 7 , wherein the key plate comprises a material with a relative electromagnetic permeability greater than five hundred.
13. A throwable surveillance robot having a housing defining a cavity and weighing less than six pounds comprising:
a tamper resistant system comprising:
a magnet disposed inside the housing cavity, the magnet being located near a key holding slot;
a key member conforming to the key holding slot, the key member comprising a material so that the magnetic flux field produced by the magnet changes when the key member is disposed in the key holding slot from a first magnetic field to a second magnetic field when the key member is not disposed in the key holding slot;
a magnetic field sensor disposed inside the housing cavity, the magnetic field sensor tripping when the first magnetic field is present, wherein tripping the magnetic field sensor causes the magnetic field sensor to change from providing a first output signal to providing a second output signal.
14. The throwable surveillance robot of claim 13 , wherein the tamper resistant system is sensitive to the specific location and orientation of the key member.
15. Throwable surveillance robot of claim 13 , wherein the sensor trips at a first vertical magnetic field strength, and releases at a second vertical magnetic field strength.
16. The throwable surveillance robot of claim 13 , wherein the magnetic field sensor has a trip point of 60 mT and a release point of 45 mT.
17. The throwable surveillance robot of claim 13 , wherein the key member is retained in place by a magnetic field of the magnet.
18. The throwable surveillance robot of claim 13 , wherein the key member is ferromagnetic.
19. The throwable surveillance robot of claim 13 , wherein the housing is a cylindrical body extending between a pair of drive wheels.
20. The throwable surveillance robot of claim 13 , wherein tripping the magnetic field sensor enables or disables the robot.