Inclined Marking Strip Scale for Absolute Position Measurement
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing measuring devices, such as magnetic linear scales, are limited in their ability to determine absolute positions over large distances due to the ambiguity in bit pattern widths and the need for additional indexing, which restricts the maximum measurable distance.
Innovation Solution
A measuring device with a scale tape featuring inclined marking strips and two detection sensors arranged on either side of the tape, allowing for the detection of angles of inclination to determine the position of a first body relative to a second body, enabling precise positioning over a larger range without the need for additional indexing or offset sensors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If additional indexing tracks or distinguishable bit patterns are used to determine absolute position, then measurement precision is improved, but device complexity increases and maximum measurement distance is limited
Solution Approach 1:
The marking strips are designed with asymmetric inclination angles relative to the transverse direction. Each marking strip transition has a unique angle of inclination that differs from all other transitions. This asymmetric angular encoding allows absolute position determination without requiring additional indexing tracks, as each position can be uniquely identified by its characteristic angle pattern.
Solution Approach 2:
Instead of using additional spatial dimensions (extra tracks) or varying bit pattern widths, the invention changes the angular parameter of the marking strips. The angle of inclination becomes the distinguishing feature that encodes absolute position information, allowing unambiguous position determination over large distances without increasing device complexity.
2Measurement precision
If additional indexing tracks are used to make bits distinguishable, then measurement precision is improved, but the maximum measurement distance is limited
Solution Approach 1:
The asymmetric angular encoding of marking strips provides unique position identification throughout the entire measurement range. Since each position is defined by a unique angle combination rather than by position within a limited bit pattern cycle, the measurement distance is no longer constrained by the length required to repeat distinguishable patterns.
Solution Approach 2:
The invention transitions from encoding position information in the spatial dimension (additional tracks) to encoding it in the angular dimension. By measuring the angle of inclination of marking strip transitions, the system accesses an additional encoding dimension that allows unambiguous absolute position determination over extended distances without requiring proportional increases in physical track length.
3Measurement precision
If distinguishable bit patterns with varying widths are used, then absolute position determination is improved, but manufacturing precision requirements increase
Solution Approach 1:
Rather than requiring precise control of bit pattern widths, the invention uses asymmetric angular orientations of marking strips. The distinguishing feature is the angle of inclination, which can be manufactured with standard precision while providing unique positional encoding. This avoids the need for high-precision control of linear dimensions.
Solution Approach 2:
The invention changes the encoding parameter from linear width variations to angular inclination variations. This parameter substitution allows absolute position determination while reducing manufacturing precision requirements, as angular features are more tolerant of standard manufacturing variations compared to precise linear dimension control.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables exact determination of the relative position of two bodies over a larger distance range by utilizing the angles of inclination of the marking strips, providing unambiguous absolute position measurement without the limitations of traditional bit pattern widths and indexing.
Implementation Method 1
the marking detection sensors are optical sensors or cameras
Implementation Method 2
the marker strips are formed by permanent magnetic poles of the scale tape and the marker detection sensors are magnetic sensors
Implementation Method 3
the magnetic sensors are magnetoresistive sensors or Hall sensors
Implementation Method 4
the magnetic sensors are magnetoresistive sensors or Hall sensors
Data Source
Figure 1~2
AI summary
A measuring device (1) for measuring the position of a first body (2) relative to a second body (3) comprises a scale band (4) attachable to the first body (2) and having a marking, and two marking detection sensors (5, 6) attachable to the second body (3), wherein the marking is formed by a pattern of marking strips (7) whose transitions (8) between a first position (9) of the scale band (4) and a second position (10) are each inclined at a respective angle (13) such that each of the angles of inclination (13) has a value that differs from the values of the other angles of inclination, wherein the scale band (4) is divided into a first track (17) and a second track (18), wherein one of the marking detection sensors (5) is arranged adjacent to the first track (17) and the other of the marking detection sensors (6) is arranged adjacent to the second track (18), and the Mark detection sensors (5,6) are arranged side by side between the first position (9) and the second position (10) when viewed in the transverse direction (12) of the scale band (4), so that the position of the first body (2) relative to the second body (3) within the first and second positions (9, 10) can be determined by detecting the angles of inclination (13). According to a method, the position of the bodies (2, 3) is determined based on the detected angles of inclination (13).