Vehicle Wheel Absolute Angular Position Determination
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for determining the absolute angular position of a vehicle wheel are either slow or unreliable, particularly at low speeds and during reverse motion, due to issues with signal detection and counting by Hall elements.
Innovation Solution
A device comprising a wheel unit mounted on the wheel to determine data enabling reference leg identification, which is then wirelessly transmitted to a receiving unit on the vehicle, allowing for the determination of an absolute angular position using a measuring device that generates signals per predetermined angle and a counting device, along with acceleration or magnetic field sensors to account for speed changes and wheel rotation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a tooth of the gear wheel is omitted to infer absolute angular position, then the absolute angular position can be determined, but the method requires correlation analysis which is very slow and needs many revolutions
Solution Approach 1:
The patent applies preliminary action by pre-establishing a reference position using an acceleration sensor to detect the contact area of the wheel. This reference position is determined before speed measurement begins, allowing the Hall element signals to be directly correlated with absolute angular position without requiring slow correlation analysis over many revolutions. The reference leg is marked in advance using gravitational acceleration data, enabling immediate absolute position determination.
Solution Approach 2:
The patent introduces an acceleration sensor as an intermediary device that works together with the Hall element. The acceleration sensor detects the reference position (contact area) independently, providing a reference signal that mediates between the Hall element teeth detection and the absolute angular position calculation. This intermediary reference signal eliminates the need for slow correlation analysis while maintaining measurement precision.
2Productivity
If Hall elements are used to count teeth passing, then rotational speed can be determined, but it is not possible to determine absolute angular position
Solution Approach 1:
The patent merges two different measurement approaches: the Hall element-based tooth counting method for rotational speed determination and the acceleration sensor-based reference position detection for absolute angular position determination. By combining these two systems, the patent achieves both rotational speed measurement and absolute angular position determination simultaneously, resolving the limitation of using Hall elements alone.
Solution Approach 2:
The patent makes the wheel monitoring system multi-functional by enabling it to perform both rotational speed measurement (using Hall elements counting teeth) and absolute angular position determination (using acceleration sensor reference detection). The system universally handles both functions through integrated signal processing that correlates Hall element signals with the acceleration sensor reference position.
3Adaptability or versatility
If the wheel unit transmits data wirelessly, then the reference leg can be determined independently of mounting position, but additional components are required
Solution Approach 1:
The wheel unit performs self-service by autonomously determining its own reference position using the acceleration sensor and wirelessly transmitting this information to the control unit. This self-determination capability makes the system independent of mounting position, as the wheel unit automatically identifies its contact area and communicates it without requiring external calibration or positioning procedures.
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 quick and reliable determination of the absolute angular position of the wheel, independent of mounting position, and corrects for errors at low speeds and reverse motion by re-establishing the reference leg when vehicle speed changes.
Implementation Method 1
the wheel unit (10a, 10b, 10c, 10d) is set up to determine data that enable a reference leg of the wheel to be determined
Implementation Method 2
or a magnetic field sensor and be set up to determine the data on the basis of a geomagnetic field acting on the magnetic field sensor
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
A device and a method for determining an absolute angular position of a wheel of a vehicle. A wheel unit is mounted on the wheel side and configured to determine data which permit a reference limb of the wheel, and to wirelessly transmit the acquired data. A receiver unit is mounted on the vehicle side and receives the data of the wheel unit. A reference limb-determining device determines the reference limb of the wheel on the basis of the received data. A measuring device generates, in each case, one signal when the wheel rotates by a previously determined angle, and a counting device counts the signals generated by the measuring device. An angle-determining device determines an absolute angular position of the wheel on the basis of the signals counted by the counting device, and on the basis of the specific reference limb.