Position-based motion controller
First Claim
1. In a muscle exercise and diagnostic system having a shaft for defining a fixed axis of rotation and body interface means for coupling motion of a body to the shaft so that the shaft rotates in response to motion of the body, a motion controller comprising:
- velocity selecting means for selecting a desired velocity;
position sensing means for detecting a current rotational position of the shaft and for providing a current position indicating signal in response thereto;
position predicting means, coupled to the velocity selecting means and to the position sensing means, for predicting a first subsequent rotational position of the shaft based on the selected velocity and the current rotational position of the shaft; and
motion controlling means, coupled to the shaft and to the position sensing means, for controlling the rotation of the shaft in response to the position indicating signal and the first predicted position.
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Accused Products
Abstract
An isokinetic exercise system includes an active exercise resistance unit and a computer controller. The active exercise resistance unit includes a lever arm assembly attached to a motor, and a patient attachment cuff is slidingly mounted to the lever arm assembly. A potentiometer is used to determine the length of the patient'"'"'s limb, and a potentiometer/optical encoder assembly is used to determine the angular position of the lever arm assembly as the limb is exercised. A strain gauge assembly is used to determine the torque applied to the lever arm assembly. The limb length, position and torque values are converted into digital form and supplied to a computer. The computer accepts selected velocity and maximum torque value from the operator and uses these values to control the velocity of and torque applied to the lever arm assembly. More specifically, the computer predicts a subsequent lever arm angular position based on the set velocity. If the actual subsequent angular position of the lever arm assembly does not match the expected position, then motor current is directly adjusted to ensure that subsequent actual and calculated positions of the lever arm match. The exercise system also includes a torque limiting function wherein the torque applied to the lever arm or patient attachment device is limited to a set maximum. If the patient attempts to exceed this maximum torque, then the motor accelerates the lever arm to keep the torque within the prescribed limits.
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Citations
17 Claims
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1. In a muscle exercise and diagnostic system having a shaft for defining a fixed axis of rotation and body interface means for coupling motion of a body to the shaft so that the shaft rotates in response to motion of the body, a motion controller comprising:
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velocity selecting means for selecting a desired velocity; position sensing means for detecting a current rotational position of the shaft and for providing a current position indicating signal in response thereto; position predicting means, coupled to the velocity selecting means and to the position sensing means, for predicting a first subsequent rotational position of the shaft based on the selected velocity and the current rotational position of the shaft; and motion controlling means, coupled to the shaft and to the position sensing means, for controlling the rotation of the shaft in response to the position indicating signal and the first predicted position. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
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Specification