Implement Controller Pitch Rate Correction via Gravity Frame Conversion
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Solution Overview
Problem
Conventional earth-moving machines face instability and control issues due to inaccurate pitch rate measurements, as gyros in 4 DOF IMUs provide unreliable pitch rate indications relative to the gravity reference frame, leading to instability in earth-moving implements like blades or buckets.
Innovation Solution
An implement controller that includes pitch, roll, and turning rate sensors, along with a processor to convert pitch rate measurements from the body reference frame to the gravity reference frame, enabling precise control of earth-moving implements by calculating the pitch rate in the gravity reference frame using roll and yaw rate data.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a 4 DOF IMU with gyroscope is used to measure pitch rate, then the measurement is reliable relative to the body reference frame, but the measurement becomes unreliable relative to the gravity reference frame
Solution Approach 1:
The patent introduces an intermediary computational process that uses additional sensors (accelerometers, magnetometers, GPS) to calculate the relationship between the body reference frame and gravity reference frame. This intermediary system converts the gyroscope's body-frame measurements into gravity-frame measurements through coordinate transformations, resolving the reliability issue without replacing the gyroscope itself.
Solution Approach 2:
The patent makes the IMU system multi-functional by using the same sensor suite for multiple purposes: the gyroscope provides body-frame pitch rate, while the accelerometers and other sensors simultaneously provide data for calculating the gravity-frame orientation. This allows a single system to serve both reference frames reliably.
2Adaptability or versatility
If the machine turns on a hill, then the machine's orientation relative to earth changes, but the gyroscope does not detect the pitch change
Solution Approach 1:
The patent implements feedback by continuously monitoring the machine's orientation using multiple sensors and comparing the body-frame measurements with the calculated gravity-frame orientation. When discrepancies are detected (such as during turns on hills), the system uses this feedback to correct the pitch angle measurement, ensuring accuracy regardless of terrain or maneuver conditions.
3Stability of the object's composition
If pitch rate measurement is inaccurate, then the earth moving implement becomes unstable, but adding correction systems increases device complexity
Solution Approach 1:
The patent merges the pitch rate correction functionality with the existing implement control system. Rather than adding a separate correction system, the patent integrates the gravity-frame calculation and pitch correction into the existing controller that already manages the earth moving implement, achieving stability improvement without proportionally increasing overall system complexity.
Data Source
AI summary
A system and method of controlling an earth moving implement of a machine is disclosed. The method may include receiving a pitch rate of the machine in a body reference frame and determining a roll of the machine. The method may further include determining a turning rate of the machine and calculating a pitch rate of the machine in a gravity reference frame based on the pitch rate of the machine in the body reference frame, the roll of the machine, and the turning rate of the machine. The method may further include controlling the earth moving implement based on the pitch rate of the machine in the gravity reference frame.