High resolution absolute vector encoder
AssigneeMOTX Ltd.
InventorYves Villaret
Life of this patent
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Abstract
A high-resolution encoder device to measure and retrievably encode the relative position of a first part P with a second part S comprises sensible elements on part P, said sensible elements providing a variable property for sensing, such that said variable property varies over a length of said part P, a number n of sensors for sensing said variable property, said sensors being separate from each other and disposed on part S, said sensors configured to output signals in accordance with said sensing, and a processing unit connected to receive said signals from each of said n sensors and configured for succeeding ones of said relative positions to form a vector having entries from each sensor respectively, the vector defining said relative positions respectively.
Claims25
A high-resolution encoder device to measure and retrievably encode the relative position of a first part P of said encoder device with a second part S of said encoder device, said first part P and said second part S being movable with respect to one another, comprising:
- a) sensible elements disposed along a length of said first part P of said encoder device, said sensible elements providing a variable property for sensing said relative motion, such that said variable property varies over said length of said first part P;
- b) a number n of sensors for sensing said variable property, said sensors being separate from each other and disposed along said second part S, said sensors configured to output signals in accordance with said sensing of said variable property;
- c) a processing unit connected to receive said signals from each of said n sensors and configured for succeeding ones of relative positions along said first part P to form a vector V having entries from each sensor respectively, thereby defining said relative positions respectively;
- and the processing unit being configured to calculate the relative position from the vector;
- the processing unit further being configured to obtain an initial position by scanning for all possible positions until a position at which the vector function satisfies a condition
- N[Vc(X)−V]<Δ
- is found, wherein Δ is a predetermined threshold, N is a normalization function, Vc(X) is the vector of values of the analog output at position X retrieved from tables of pre-recorded data, said position satisfying said condition being usable to track said relative position.
A high-resolution encoding method to measure and retrievably encode the relative position of a first part P with a second part S, the first part P and the second part S being movable with respect to one another, the method comprising:
- a) providing a variable property for sensing such that said variable property varies over a length of said first part P, said variable property being provided via sensible elements distributed over said length of said first part P;
- b) on said second part S, sensing said variable property at n discrete locations;
- c) outputting signals from said n discrete locations in accordance with said sensing;
- d) receiving said signals from each of said n discrete locations;
- and
- e) for succeeding ones of said relative positions forming a vector V having entries from each sensor respectively, thereby defining said relative positions respectively, the encoder thereby using said vector to measure and encode said relative position;
- and
- f) obtaining an initial position by scanning for all possible positions until a position at which the vector function satisfies a condition
- N[Vc(X)−V]<Δ
- is found, wherein Δ is a predetermined threshold, N is a normalization function, Vc(X) is the vector of values of the analog output at position X retrieved from tables of pre-recorded data, said position satisfying said condition being usable to track said relative position.
Dependencies are inferred from the claim text.