Autonomous safety system for a treadmill

1. A method for operating an exercise treadmill, comprising:

measuring an initial height of a user standing on a stationary treadmill belt before the treadmill belt is started in motion;

saving the initial height in memory;

enabling a treadmill motor to start moving the treadmill belt only after measuring the initial height of the user;

continuously measuring a current height of the user on a moving treadmill belt as a distance from a top of a head of the user on the moving treadmill belt to a surface of the moving treadmill belt;

evaluating the current height against the initial height to detect when the current height is lower than the initial height by a minimum threshold distance of 1-2 inches, thereby generating a first treadmill motor control signal for stopping the treadmill belt when the user is starting to fall and (a) before the user has fallen onto or off of the moving treadmill belt or (b) before the user moves to the back of the moving treadmill belt; and

stopping the treadmill motor from moving the treadmill belt in response to the first treadmill motor control signal.

2. The method of claim 1 , where measuring the initial height comprises measuring the initial height of the user from an image collected by an RGB camera sensor.

3. The method of claim 1 , where measuring the initial height comprises measuring the initial height of the user with a laser rangefinder device.

4. The method of claim 1 , where measuring the initial height comprises measuring the initial height of the user with a depth camera.

5. The method of claim 1 , where continuously measuring the current height comprises periodically measuring the current height of the user while the treadmill is in use.

6. The method of claim 1 , where stopping the treadmill motor comprises:

comparing a current speed of the treadmill belt to a predetermined maximum speed;

decelerating the current speed of treadmill belt to a specified slower speed in response to the first treadmill motor control signal if the current speed exceeds the predetermined maximum speed; and

stopping the treadmill belt after the treadmill belt reaches the specified slower speed.

7. An exercise treadmill, comprising:

a frame structure for housing a treadmill motor driving a treadmill belt;

one or more height sensors connected to the frame structure for making height measurements of a treadmill user; and

a control system, operatively connected to said treadmill motor and one or more height sensors, configured to evaluate an initial height measurement of the treadmill user on the stationary treadmill belt before the treadmill belt is started in motion against one or more subsequent height measurements of the treadmill user on the moving treadmill belt taken during operation of the exercise treadmill and generate a treadmill motor control signal for stopping the treadmill motor when a subsequent height measurement of one or more subsequent height measurements is lower than the initial height measurement by a predetermined threshold distance of 1-2 inches so that the treadmill belt is stopped when the user is starting to fall and (a) before the user has fallen onto or off of the moving treadmill belt or (b) before the user moves to the back of the moving treadmill belt, wherein the treadmill belt is configured to start in motion only after the initial height measurement is measured.

8. The exercise treadmill of claim 7 , where the control system and one or more height sensors are configured to make the initial height measurement by measuring a topmost point on a head of the treadmill user standing on the stationary treadmill belt in relation to a point on a surface of treadmill belt or on a surface on which the exercise treadmill rests.

9. The exercise treadmill of claim 7 , where the one or more height sensors comprise one or more RGB camera sensors, laser rangefinder devices, or depth cameras.

10. The exercise treadmill of claim 7 , where the control system is configured to stop the treadmill motor by:

comparing a current speed of the treadmill belt to a predetermined maximum speed;

decelerating the current speed of treadmill belt to a specified slower speed in response to the treadmill motor control signal if the current speed exceeds the predetermined maximum speed; and

stopping the treadmill belt after the treadmill belt reaches the specified slower speed.

11. The exercise treadmill of claim 7 , where the control system is configured to stop the treadmill motor by:

comparing a current speed of the treadmill belt to a predetermined maximum speed; and

stopping the treadmill belt in response to the treadmill motor control signal if the current speed does not exceed the predetermined maximum speed.

12. A method for operating an exercise treadmill, comprising:

determining an initial distance from a top of a head of a user standing on a stationary treadmill belt of the exercise treadmill to a surface of the stationary treadmill belt before the treadmill motor starts to move the treadmill belt;

saving the initial distance from the top of the head of the user to the surface of the treadmill belt;

enabling a treadmill motor to start moving the treadmill belt only after determining the initial distance;

continuously determining a current distance from the top of the head of the user on a moving treadmill belt to the surface of the moving treadmill belt;

comparing the saved initial distance to the current distance to determine when the user first starts to fall;

generating a first treadmill motor control signal to stop the treadmill motor when the current distance from the top of the head of the user to the moving treadmill belt is lower than the saved initial distance by a predetermined threshold distance so that the treadmill belt may be stopped when the user is starting to fall and (a) before the user has fallen onto or off of the moving treadmill belt or (b) before the user moves to the back of the moving treadmill belt.

13. The method of claim 12 , where the predetermined threshold distance is one to two inches.

14. The method of claim 12 , where the predetermined threshold distance is greater than a minimum of two inches.

15. A method for operating an exercise treadmill, comprising:

powering on the exercise treadmill without applying power to a treadmill motor so that a treadmill belt is not moving;

measuring an initial distance from a top of a head of a user standing on the treadmill belt to a surface of the treadmill belt that is not moving;

saving the initial distance from the top of the head of the user to the surface of the treadmill belt;

turning on the treadmill motor so that the treadmill belt is moving, wherein the treadmill motor is enabled to move the treadmill belt only after the initial distance is measured;

measuring a current distance from the top of the head of the user to the surface of the moving treadmill belt while the treadmill belt is moving;

evaluating the current distance against the initial distance to detect when the current distance has dropped by a minimum threshold distance from the initial distance, thereby generating a treadmill motor control signal for stopping the treadmill belt when the user is starting to fall and (a) before the user has fallen onto or off of the moving treadmill belt or (b) before the user moves to the back of the moving treadmill belt; and

stopping the exercise treadmill in response to the treadmill motor control signal.

16. The method of claim 15 , where the minimum height threshold distance is one to two inches.