Southwest Research Institute

Gm Global Technolgoy Operations, Inc.

Bapiraju Surampudi

Joe Steiber

Jayant V Sarlashkar

Kevin Jones

Junmin Wang

Gary L Stecklein

Benjamin R Furman

Jeff Qiang Xu

Paul A Piorkowski

Alfonso G Hysko

David T Stark

Venkata Rajesh Chundru

Robert M Senseney

Marlin R Turbett

Matthew S Castiglione

Benjamin A Treichel

Mickey E Argo, Jr

Shuvodeep Bhattacharjya

David L Joseph

Robert W Tator

Michael R Rosati

Steven D Nash

Battery testing and monitoring by determining battery characteristics such as an increase thickness of the battery SEI layer, extent of lithium-ion plating, loss of cyclable lithium, dendrite growth (and extent), and/or other characteristics that may impact the performance and/or safety of a lithium-ion battery. The battery characteristics may be determined at perioding intervals using test data that includes voltage and current at various charging levels and state of charge, thus providing impedance profiles that can be compared to modelled and/or known thresholds of battery conditions.

Systems and methods for battery performance monitoring

A method of developing a charging profile for charging a lithium-ion battery. A first phase of charging is at a constant current level, with the constant current level selected on the basis of battery resistance during charging and differential voltage (dV/dQ) analysis. A switch point is selected on the basis of a state of charge (SOC) of the battery when dV/DQ values increase. Next is an increasing voltage charging phase, with the voltage rate selected on the basis of charge acceptance and charge time.

Development of fast charge profiles for lithium-ion batteries

A method of charging a lithium-ion battery. It is assumed that the battery has a cooling system. A desired temperature profile for the battery during charging is determined. The charge current is pulse width modulated (PWM), as is the activation of the cooling system. During charging, various parameters of either or both of the PWM signals are adjusted such that the desired temperature profile is maintained.

Fast charging for lithium-ion batteries using pulse width modulated charging and cooling

In general, the present disclosure is directed to forming lithium ion battery (LIB) cells with structure and chemistry that achieves formation of a solid electrolyte interphase (SEI) layer that allows for operating in relatively high ambient temperature environments, e.g., up to and exceeding 60&#xb0; C., while significantly reducing self-discharge amounts, e.g., relative to other LIB cells formed with SEI layers measuring about 1-2 nanometers in thickness. For example, one non-limiting embodiment of the present disclosure enables a self-discharge amount for a LIB cell of 10% or less over a four (4) week period of time when operating at an ambient temperature of 60 degrees Celsius.

Techniques for forming thermally resilient energy storage devices and a battery thermal management system implementing same

A method of controlling the charge current during charging of a lithium-ion battery. A battery charging controller is based on a Kalman filter, which uses estimated battery states to generate a feedback metric to continually adjust a battery cell model. The battery cell model then delivers data to an optimization process that generates the charge current.

Control of lithium plating of lithium-ion battery during charging

A system and method for providing an application-independent estimation of the state of health (SOH) of a battery. A battery terminal voltage, under a non-zero load, when a specific amount of charge has been drawn from the battery is compared to stored terminal voltage test data obtained under the same conditions. An estimate of SOH is provided in response to the comparison.

System and method for estimating battery state of health

A system for simulating the effects of use and aging on immersive coolants. Two conductive coils are immersed in a tank containing a sample of the coolant. The coils are spaced such that electrical activation of the first coil induces current in the second coil. A DC power source is provided to an inverter, which provides AC current for activating the first coil. The induced AC current in the second coil is delivered to a rectifier which converts the induced AC current to DC current. The DC current is then returned to the power source. The electromagnetic field between the coils simulates motor operation, so that the coolant's physical and chemical characteristics can be tested for the effects of use and aging.

Simulating use and aging of immersive coolants for electric motors

A method and system for application independent map-based cycle life testing of battery cells is provided. A target depth of discharge (DOD) and a charge/discharge current level is selected for the battery test. The battery is discharged to the target DOD. The battery is cycled within the DOD range one or more times, wherein the cycling comprises a charge pulse and a discharge pulse at the selected current levels. A reference performance test (RPT) is performed on the battery, wherein the RPT comprises a static capacity test and a dynamic power test. The cycling and RPT testing are repeated until an end of test condition is detected.

Application independent map-based cycle life testing of battery cells

A landmark-based method of estimating the position of an AGV (autonomous ground vehicle) or conventional vehicle, which has an onboard database of landmarks and their locations coordinates. During travel, the AGV looks for and identifies landmarks. It navigates according to position estimations that are based on measured yaw rate and speed. When a landmark s encountered and recognized, its true location coordinates are looked up from the database. These true coordinates are then used to enhance position estimation accuracy between landmarks.

Position estimation for ground vehicle navigation based on landmark identification/yaw rate and perception of landmarks

The present disclosure relates to a reference yaw rate generator for an autonomous ground vehicle control system. The reference yaw rate generator is configured to generate a reference yaw rate (r) based on an actual latitudinal position (Y), a desired latitudinal position (Y), an actual longitudinal position (X), a desired longitudinal position (X) and an actual heading (&#x3c8;) of the autonomous ground vehicle.

Autonomous ground vehicle control system for high-speed and safe operation

A method of controlling the shifting of an automatic manual transmission is based on observer-based timing of different phases of the shift process. The observer-based control strategy includes simultaneous management of the engine throttle and transmission actuators. The torque characteristics of the transmission are also taken into consideration during control of the engine throttle, thereby minimizing shift time and wear on transmission components. The control strategy uses mathematical models called observers to monitor the value of inherent properties attributable to specific actuators and to provide signals used to implement parallel task execution.

Observer-based control method for automatically shifting a manual transmission

The virtual vehicle transmission test cell includes an electric motor which simulates a fuel driven engine, an output motor which simulates the load a transmission experiences in a vehicle, and an environmental element which controls the ambient environment of the transmission and the temperature of the transmission oil within the transmission. The virtual vehicle transmission test cell reduces in-vehicle testing, reduces testing with fuel-driven test cells, and enables development of a transmission design before a corresponding engine is completed and built for testing.

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San Antonio, TX, United States of America

Bapiraju Surampudi