Exercise device
A personal exercise device with a cable and resistance mechanism comprises a sensor arrangement configured to detect two orthogonal angles to define a trajectory of the cable extending in a 3-dimensional space during use. The sensor arrangement comprises a pulley to direct the cable as it extends from the device during use, a cable follower through which the cable passes, the cable follower pivotally mounted to pivot about a first pivot axis and about a second pivot axis, the second pivot axis orthogonal to the first pivot axis, and wherein the first pivot axis is collinear with a rotational axis of the pulley, and one or more sensors configured to detect pivoting of the cable follower about the first and second pivot axes and provide one or more outputs indicative of the two orthogonal angles to define the trajectory of the cable extending in the 3-dimensional space.
1. A personal exercise device comprising:
a user interface to be moved by a user in a 3-dimensional space when using the personal exercise device;
a resistance mechanism to generate a force;
a cable coupled between the user interface and the resistance mechanism to transmit the force from the resistance mechanism to the user interface; and
a sensor arrangement configured to detect two orthogonal angles to define a trajectory of the cable extending in the 3-dimensional space during use, the sensor arrangement comprising:
a pulley to direct the cable as it extends from the personal exercise device during use, the pulley comprising a rotational axis;
a cable follower through which the cable passes, the cable follower pivotally mounted to pivot about a first pivot axis and about a second pivot axis, the second pivot axis orthogonal to the first pivot axis, and wherein the first pivot axis is collinear with the rotational axis of the pulley, and
one or more sensors configured to detect pivoting of the cable follower about the first and second pivot axes and provide one or more outputs indicative of the two orthogonal angles to define the trajectory of the cable extending in the 3-dimensional space.
2. The personal exercise device as claimed in claim 1 , wherein the cable follower is mounted on a pivoting frame, the pivoting frame pivotally mounted to pivot on the rotational axis of the pulley.
3. The personal exercise device as claimed in claim 2 , wherein the pivoting frame and the pulley are mounted together on a single axle.
4. The personal exercise device as claimed in claim 2 , wherein the cable follower is pivotally mounted to the pivoting frame to pivot relative to the pivoting frame about the second pivot axis.
5. The personal exercise device as claimed in claim 4 , wherein the second pivot axis is aligned with a central plane of the pulley.
6. The personal exercise device as claimed in claim 2 , wherein the pulley, pivoting frame and cable follower are pivotally mounted on one or more pivot mounts to pivot about the second pivot axis.
7. The personal exercise device as claimed in claim 6 , wherein the pulley and pivoting frame are mounted on an axle supported by one or more axle supports, and the one or more axle supports are mounted to the one or more pivot mounts to pivot on the second pivot axis.
8. The personal exercise device as claimed in claim 1 , wherein a first angle of the two orthogonal angles is an angle of the cable follower in a first plane perpendicular to the rotational axis of the pulley.
9. The personal exercise device as claimed in claim 8 , wherein the first plane pivots on the second pivot axis with the pulley.
10. The personal exercise device as claimed in claim 8 , wherein the first angle is indicative of an angle of wrap of the cable about the pulley.
11. The personal exercise device as claimed in claim 8 , wherein a second angle of the two orthogonal angles is an angle of the cable follower in a vertical second plane orthogonal to the first plane, between the first plane and a vertical plane that intersects the first plane at the second pivot axis.
12. The personal exercise device as claimed in any one of claim 11 , wherein the one or more sensors comprises:
a first sensor configured to detect the pivoting of the cable follower about the first pivot axis and provide an output indicative of the first angle, and
a second sensor configured to detect the pivoting of the cable follower about the second pivot axis and provide an output indicative of the second angle.
13. The personal exercise device as claimed in claim 12 , wherein the sensor arrangement further comprises gears between the pivoting frame and the first sensor or a sensor element sensed by the first sensor, the gears providing an increasing gear ratio from the pivoting frame to the first sensor or the sensor element.
14. The personal exercise device as claimed in claim 1 , wherein the sensor arrangement further comprises limit stops to limit an amount of pivoting of the cable follower about the first pivot axis and/or second pivot axis.
15. The personal exercise device as claimed in claim 1 , wherein the second pivot axis is collinear with the cable extending on a resistance mechanism side of the pulley.
16. The personal exercise device as claimed in claim 1 , wherein:
the resistance mechanism comprises an electric motor and a spool rotationally driven by the electric motor, and wherein the cable is coupled to the spool; and
the personal exercise device comprises a motor controller configured to operate the electric motor to generate the force.
17. The personal exercise device as claimed in claim 1 , further comprising a position sensor and a system controller configured to determine:
a length of cable extending in the 3-dimensional space based on one or more outputs from the position sensor;
the two orthogonal angles based on the one or more outputs from the one or more sensors; and
a position of the user interface in the 3-dimensional space during use based on the length of the cable and the two orthogonal angles.
18. The personal exercise device as claimed in claim 17 , wherein the system controller is configured to provide feedback to the user via a feedback device based on the position of the user interface in the 3-dimensional space.
19. The personal exercise device as claimed in claim 1 , wherein the sensor arrangement is mounted within a recess in a top of a housing of the personal exercise device.
20. A method for determining a position of a user interface of a personal exercise device in a 3-dimensional space during use, the personal exercise device comprising:
the user interface, a resistance mechanism to generate a force, a cable coupled between the user interface and the resistance mechanism to transmit the force from the resistance mechanism to the user interface, and a pulley directing the cable from the personal exercise device in the 3-dimensional space, and a cable follower through which the cable passes, the cable follower pivotally mounted to pivot about a first pivot axis and a second pivot axis, the second pivot axis orthogonal to the first pivot axis;
wherein the method comprises:
determining a length of cable extending in the 3-dimensional space;
determining two orthogonal angles to define a trajectory of the cable extending in the 3-dimensional space based on pivoting of the cable follower about the first and second pivot axes; and
determining the position of the user interface in the 3-dimensional space during use based on the length of the cable and the two orthogonal angles.
21. The method of claim 20 , wherein the first pivot axis is collinear with a rotational axis of the pulley.