Vehicle Drive System Brake Coordination Controller

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Solution Overview

Problem

Existing vehicle electric drive systems lack coordination with the vehicle brake system, requiring operators to separately manage speed reduction using both brakes and the electric drive system, leading to potential abrupt speed changes.

Innovation Solution

A vehicle drive system that includes a controller coupled to the inverter/rectifier, receiving brake position signals to coordinate the operation of the electric drive system with the brake command members, allowing the traction motor/generator to function as a generator and the driven motor/generator to function as a motor when a brake command is applied, thereby decelerating the vehicle with increasing aggressiveness and preventing abrupt speed changes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the operator applies brakes to reduce vehicle speed, then vehicle deceleration is achieved, but the electric drive system does not coordinate with braking causing potential abrupt speed changes

Engineering Contradiction:
Improvebraking coordinationVSAvoidspeed control smoothness
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent merges the brake system and electric drive system into a coordinated unified control system. The controller receives brake position signals and electric drive position signals, processes them together, and generates coordinated control commands for both systems, ensuring they work synergistically rather than independently

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent implements feedback mechanisms by having the controller continuously monitor brake position signals from brake sensors and electric drive position signals from the electric drive system. This feedback loop enables real-time coordination and adjustment of both systems to prevent abrupt speed changes and ensure smooth operation

Inventive Principle:
Principle #23Feedback

2Productivity

If the operator separately manages speed reduction using both brakes and electric drive system, then speed control is possible, but operation complexity increases

Engineering Contradiction:
Improvespeed control capabilityVSAvoidcontrol system complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The controller serves multiple functions: it controls the electric drive system, processes brake position signals, coordinates braking operations, and manages the interaction between the electric drive and brake systems. This multi-functionality consolidates what would otherwise be separate control systems into a single unified controller

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The controller acts as an intermediary between the brake system and electric drive system. It receives inputs from both systems, processes them centrally, and generates coordinated outputs, mediating the interaction to simplify the overall control architecture while maintaining full functionality

Inventive Principle:
Principle #24Intermediary (Mediator)

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

The system ensures responsive and coordinated vehicle braking, limiting deceleration and acceleration to prevent abrupt speed changes, allowing the electric drive system to assist conventional braking and maintain smooth vehicle speed control.

Implementation Method 1

brake transducers or sensors, each coupled to a corresponding one of the brake command members, and generating a brake position signal representing a position of the corresponding brake command member

Methodology Applied
Scientific EffectPosition sensing:

Implementation Method 2

a first inverter/rectifier coupled to the driven motor/generator, a buss coupled to the first inverter/rectifier, a second inverter/rectifier coupled to the buss

Methodology Applied
Scientific EffectElectrical energy conversion:

Implementation Method 3

a traction motor/generator coupled to an output of the second inverter/rectifier and drivingly coupled to driven vehicle wheels

Methodology Applied
Scientific EffectElectromagnetic conversion: Electromagnetic Induction

Implementation Method 4

the controller receiving the brake position signals and coordinating operation of the electric drive system with operation of the brake command members

Methodology Applied
Scientific EffectSpeed control coordination:

Data Source

PatentEP1958838B1Vehicle drive system
Publication Date: 2017.10.04 DEERE & CO
  • EP1958838B1 patent drawingFigure 1
  • EP1958838B1 patent drawingFigure 2
  • EP1958838B1 patent drawingFigure 3~4

AI summary

The invention relates to a vehicle drive system (10). There is a need for a brake responsive vehicle drive system (10). A vehicle drive system (10) includes an internal combustion engine (12), an electric motor/generator (14) driven by the engine (12), and drive wheels (26, 30) driven by a traction motor/generator (24, 28). The motor/generators (24, 28) are controlled by a controller (40) which receives signals from an operator speed control member (36), wheel speed sensors (46, 48), and a pair of brake pedal position sensors (58, 60), each connected to a corresponding left or right brake pedal (57, 59). In response to operation of the brake pedals (57, 59), the controller (40) coordinates operation of the electric drive system with operation of the brake pedals (57, 59).