E-Bike Drive Unit Startup With Reverse Motor Initialization

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing methods for initializing electric motors in vehicles, such as electric bicycles, are inefficient and disrupt normal operation, as they require time-consuming torque generation and sensor initialization during startup, which can delay full functionality and affect vehicle operation.

Innovation Solution

A method that rapidly initializes the electric motor by actuating it with a predetermined starting current in the reverse direction of rotation during system start, allowing for quick initialization of the motor and sensor systems without torque generation, enabling immediate standby mode and subsequent forward rotation for propulsion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the electric motor is initialized during normal operation, then sensor initialization can be performed, but torque generation is delayed and vehicle operation is disrupted

Engineering Contradiction:
Improvesensor initializationVSAvoidtorque generation speed
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent performs sensor initialization and motor calibration during a pre-start phase before the motor is needed for propulsion. The control unit executes initialization routines including sensor checks, encoder calibration, and current sensor validation before the vehicle begins moving, ensuring the motor is fully ready without delaying actual operation

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The startup process is divided into distinct phases: a pre-start initialization phase where sensors are calibrated and motor parameters are set, followed by a transition phase, and then normal operation phase. This segmentation allows initialization to occur without interfering with torque generation when needed

Inventive Principle:
Principle #1Segmentation

2Power

If the electric motor is actuated with high current during startup, then full torque can be generated quickly, but the startup process takes longer due to initialization requirements

Engineering Contradiction:
Improvetorque outputVSAvoidstartup time
Core Design Contradiction:
PowerVSLoss of time

Solution Approach 1:

All initialization tasks including sensor validation, encoder calibration, and motor parameter setup are completed before the motor needs to deliver full torque. The control unit executes these preparatory routines during the pre-start phase, so when the vehicle begins moving, the motor can immediately provide full power without delay

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements a streamlined startup sequence that quickly transitions through initialization phases. The control unit performs essential checks in rapid succession and bypasses unnecessary delays, enabling the motor to reach full operational capacity faster while still completing required initialization steps

Inventive Principle:
Principle #21Skipping (Rushing through)

3Ease of operation

If the electric motor rotates in forward direction during startup, then torque can be transmitted to drive the vehicle, but sensor initialization cannot be performed independently

Engineering Contradiction:
Improvevehicle propulsionVSAvoidinitialization process
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent separates the initialization process from the propulsion process by creating a distinct pre-start phase. During this phase, the motor remains stationary while sensors are calibrated and validated. Only after successful initialization does the system transition to forward rotation and torque transmission, allowing both functions to occur without interference

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The control unit acts as an intermediary that manages the transition between initialization and operation. It coordinates sensor calibration, validates motor parameters, and only after confirming system readiness does it enable forward rotation and torque transmission, ensuring both initialization and propulsion requirements are met

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

Enables a rapid and efficient system start of the electric motor, allowing for immediate full functionality without disrupting vehicle operation, and allows for precise estimation of motor parameters and detection of defects using a test current, enhancing user comfort and operational reliability.

Implementation Method 1

the electric motor is actuated with a predetermined starting current such that the electric motor rotates in a reverse direction

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP4375115A1Method for operating a drive unit of a vehicle that can be operated by muscle power and/or motor power
Publication Date: 2024.05.29 ROBERT BOSCH GMBH
  • EP4375115A1 patent drawingFigure 1
  • EP4375115A1 patent drawingFigure 2
  • EP4375115A1 patent drawing

AI summary

The invention relates to a method (20) for operating a drive unit (1) of a vehicle (10) that can be operated by muscle power and/or motor power, which has an electric motor (2) and a control unit, wherein in response to a system start of the drive unit (1) the electric motor (2) is actuated with a start current such that the electric motor (2) rotates in a reverse direction.