# Johannes Stockhammer, PhD (Dr.-Ing.)

> Vehicle systems engineer and PhD in control and cyber-physical systems. Tech lead at [Rivian and Volkswagen Group Technologies](https://rivianvw.tech/), based in Irvine, California. Works on EV thermal management, heat pumps, DC fast charging and embedded control software. Creator of the mode optimization strategy for real-time mixed-integer model predictive control (MPC) of vehicle thermal management systems.

Slogan: "I control things that move — in system theory, proven in the real world."
Website: https://josto.me/ · Contact: hi@josto.me · Research: research@josto.me

## Focus areas
- Controls & optimization: model predictive control, mixed-integer optimal control, the mode optimization strategy
- Thermal & energy: battery thermal management, heat pumps, refrigerant circuits (incl. R290/propane), cabin climate, DC fast charging
- Embedded software: production embedded C for refrigerant circuit and cabin HVAC — function design, software architecture, calibration, verification from unit test to vehicle
- Research & patents: 13 patent publications in 10 patent families

## Mode optimization strategy (key result)
A thermal management system with discrete valves has several operating modes. Choosing modes and continuous controls together is a mixed-integer problem that is hard and slow to solve. The mode optimization strategy splits it into a finite outer problem (choose the sequence of modes) and smooth inner problems (one fixed mode each, no integer variables), linked recursively: the optimal end state of one inner problem is the start state of the next.
Validated in a prototype vehicle (rapid control prototyping, HIL, climatic wind tunnel). Results: about 37 % shorter fast-charging time, about 8 % higher efficiency, about 6 % energy savings in the WLTC.

## Career
- 2026–now: Tech Lead, Vehicle Systems Engineering, [Rivian and Volkswagen Group Technologies](https://rivianvw.tech/), Irvine, California
- 2023–2026: Development Engineer, Climate & Thermal Systems, [Rivian and Volkswagen Group Technologies](https://rivianvw.tech/), Germany
- 2020–2025: Dr.-Ing. (PhD), Control and Cyber-Physical Systems, TU Darmstadt, in cooperation with industry; defended October 31, 2025
- 2017–2019: Dipl.-Ing. (FH), Automotive Electronics, Westsächsische Hochschule Zwickau, completed in two years, graduated with distinction
- 2016–2017: Civilian service in development cooperation, school partnership HTL Braunau with partner schools in León (Nicaragua) and Lira (Uganda)
- 2015–2016: Diploma project: electric race kart (traction control, three-stage regenerative braking, LiFePO4 battery with own BMS); Jugend Innovativ 2016 national finalist and recognition prize
- 2011–2016: HTL Braunau, electrical engineering, graduated with distinction

## Publications
- [Dissertation (DOI 10.26083/tuda-7633)](https://doi.org/10.26083/tuda-7633): Intelligentes Thermomanagement batterieelektrischer Fahrzeuge unter Berücksichtigung verschiedener Betriebsmodi: Modellierung, Analyse und dynamische Optimierung. TU Darmstadt. In German.
- Manuscript: A novel approach using mixed-integer MPC to optimize thermal management systems in BEV (J. Stockhammer, J. Lünenstraß, R. Findeisen)
- Manuscript: A dynamic optimization approach for thermal management systems in BEVs (J. Stockhammer, S. Giraldo Zapata, T. S. Schmidt, R. Findeisen)
- [Diploma thesis (DOI 10.13140/RG.2.2.26409.76642)](https://doi.org/10.13140/RG.2.2.26409.76642): Entwickeln eines automatisierten Schaltgetriebes für Motorräder, WHZ Zwickau, 2019

## Patent publications (DPMA)
- [DE102024210144A1](https://depatisnet.dpma.de/DepatisNet/depatisnet?action=bibdat&docid=DE102024210144A1): predictive, route-based optimization of an EV thermal management system (mode optimization strategy), 2026
- [DE102025101592A1](https://depatisnet.dpma.de/DepatisNet/depatisnet?action=bibdat&docid=DE102025101592A1): charging controlled by a predicted battery and vehicle state, 2026
- [DE102024139124A1](https://depatisnet.dpma.de/DepatisNet/depatisnet?action=bibdat&docid=DE102024139124A1): battery temperature window for maximum charging power, 2026
- [DE102025100127A1](https://depatisnet.dpma.de/DepatisNet/depatisnet?action=bibdat&docid=DE102025100127A1): battery heating control, 2026
- [DE102024203197A1](https://depatisnet.dpma.de/DepatisNet/depatisnet?action=bibdat&docid=DE102024203197A1): heat pump for cabin heating using component housings as heat exchangers, 2025
- [DE102024201887A1](https://depatisnet.dpma.de/DepatisNet/depatisnet?action=bibdat&docid=DE102024201887A1): hybrid battery cooling for DC fast charging, 2025
- [DE102023210440A1](https://depatisnet.dpma.de/DepatisNet/depatisnet?action=bibdat&docid=DE102023210440A1): fleet telematics to optimize charging targets, 2025
- [DE102023208220A1](https://depatisnet.dpma.de/DepatisNet/depatisnet?action=bibdat&docid=DE102023208220A1): cabin climate control without sun or ambient sensors, 2025
- [DE102023208028A1](https://depatisnet.dpma.de/DepatisNet/depatisnet?action=bibdat&docid=DE102023208028A1): drivetrain as a heater, 2025
- [DE102023200636A1](https://depatisnet.dpma.de/DepatisNet/depatisnet?action=bibdat&docid=DE102023200636A1): heat pump secondary circuit control, 2024; also WO2024156511, EP4608660, US2026/0233579

## Skills & certifications
MATLAB/Simulink, CasADi, Python, CANape, CAN/LIN; rapid control prototyping, HIL; EU F-gas certificate Category I incl. R290 (comparable to EPA 608 Universal); HV qualification.

## Profiles
- [LinkedIn](https://linkedin.com/in/josto)
- [Google Scholar](https://scholar.google.com/citations?user=rmtca84AAAAJ)
- [ResearchGate](https://www.researchgate.net/profile/Johannes-Stockhammer-3)
- [ORCID 0009-0008-4263-5369](https://orcid.org/0009-0008-4263-5369)
- [Team page, CCPS Laboratory, TU Darmstadt](https://www.ccps.tu-darmstadt.de/ccps/team_ccps/team_details_109632.de.jsp)