Hydraulic Controller Inverse Filter Vibration Suppression

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Solution Overview

Problem

Existing hydraulic controllers for continuously variable transmissions (CVTs) face challenges in balancing responsivity and vibrations restraint-ability, leading to unstable torque transmission, belt slippage, and poor fuel efficiency due to hydraulic vibrations, which are not adequately addressed by traditional solutions like hydraulic dampers or primary lag filters.

Innovation Solution

A hydraulic controller that includes an electronic control unit (ECU) with a fundamental hydraulic-pressure command part, a feedforward control part using inverse filters for opposite-phase compensation, and a feedback control part with PID controllers, which determines a target control amount to enhance both responsivity and vibrations restraint-ability by optimizing hydraulic pressure control based on sensed values and oil temperature.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If a primary lag filter is used for control of the hydraulic actuator, then the vibrations restraint-ability is enhanced, but the responsivity is degraded

Engineering Contradiction:

Improvevibrations restraint-abilityVSAvoidresponsivity

Core Design Contradiction:

Stability of the object's compositionVSSpeed

Solution Approach 1:

The patent applies dynamics by making the lag characteristics of the filter adjustable rather than fixed. The control device changes the lag characteristics according to operating conditions, allowing the system to adapt between vibration suppression and responsivity requirements. This is achieved through a control device that modifies filter parameters based on real-time operating state.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent implements parameter changes by modifying the lag characteristics of the filter based on operating conditions. The control device adjusts filter parameters dynamically to optimize performance across different operating ranges, resolving the contradiction between vibration suppression and responsivity.

Inventive Principle:

Principle #35Parameter changes

2Speed

If the lag characteristics of the filter are reduced to enhance responsivity, then the responsivity is enhanced, but the vibrations restraint-ability is degraded

Engineering Contradiction:

ImproveresponsivityVSAvoidvibrations restraint-ability

Core Design Contradiction:

SpeedVSStability of the object's composition

Solution Approach 1:

The system dynamically adjusts filter characteristics based on operating conditions. When responsivity is prioritized, the lag characteristics are reduced; when vibration suppression is needed, lag characteristics are increased. This dynamic adaptation resolves the contradiction.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The control device changes filter parameters according to operating state, allowing the system to switch between vibration suppression mode and high responsivity mode as needed, thereby resolving the contradiction between these two opposing requirements.

Inventive Principle:

Principle #35Parameter changes

3Stability of the object's composition

If a hydraulic damper is arranged independently of the hydraulic controller to restrain hydraulic vibrations, then the vibrations restraint-ability is enhanced, but the device complexity and manufacturing cost increase

Engineering Contradiction:

Improvevibrations restraint-abilityVSAvoidsystem complexity

Core Design Contradiction:

Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The patent merges the vibration suppression function into the existing hydraulic controller by implementing it through control software/algorithms. Instead of adding a separate hydraulic damper, the vibration restraint is achieved through the control device that processes control signals, thereby suppressing vibrations without increasing mechanical system complexity.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The patent replaces the mechanical hydraulic damper with an electronic control solution. The control device uses signal processing and control algorithms to achieve vibration suppression that would traditionally require additional mechanical components, thereby reducing device complexity and manufacturing cost.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Data Source

PatentUS7715967B2Hydraulic controller and control method with pressure and oil-condition sensing and failure

Publication Date: 2010.05.11 JATCO LTD

AI summary

A hydraulic controller includes an actuator for electrically controlling the hydraulic pressure, a hydraulic-pressure sensing part for sensing an actual value of the hydraulic pressure in the actuator, and an ECU for controlling the actuator. The ECU includes a fundamental hydraulic-pressure value command part for carrying out setting and command of a fundamental hydraulic-pressure command value, a feedforward control part for calculating through an inverse filter a first target hydraulic-pressure command value in accordance with the fundamental hydraulic-pressure command value, a feedback control part for calculating a second target hydraulic-pressure command value in accordance with the sensed actual value of the hydraulic pressure and the fundamental hydraulic-pressure command value, and a target control-amount determination part for determining a target control amount of the actuator in accordance with the first and second target hydraulic-pressure command value, wherein the ECU controls the actuator in accordance with the determined target control amount.