John Deere Electronic Solutions design engineers complete an electronic design analysis to establish how we will create a circuit topology, define the component values to be used, and determine the range of performance expected. This guarantees a thorough circuit design and validates that components are compatible. It also enables us to conduct simulations and sub-circuit verifications to ensure the electronics will perform as expected, identifying and limiting potential problems prior to prototype development.
The engineering team creates schematics that tie all the validated sub-circuits together. Each design undergoes several reviews, analyses and verifications from groups of engineers representing multiple competencies, including up-front interaction with our design validation testing group. This integration of teams identifies potential problems, and feedback results in constantly improving design advancements.
Core Tools Include:
- P-Spice circuit simulation
- Mentor Graphics Expedition
- Schematics and PCB layout with auto-route capability
- ECAD interface to Pro-E mechanical tools
- Mentor Graphics Hyperlink
Printed Circuit Board Design
PCB designers work with electronic design engineers to establish placement of parts, critical trace sizes for current, and any modifications that might need to be made to enhance the board manufacturing process. Mechanical engineers collaborate with the PCB engineers concerning panelization and building processes.
Mechanical Design (Enclosures & Housings)
The mechanical design department at John Deere Electronic Solutions is particularly adept at designing housings and enclosures that protect the PCB assemblies and electronic components from the extreme temperatures, shock and vibration under which they are required to operate. Mechanical design is a cross-functional effort to ensure designs meet all functional requirements and any required vehicle, user and harnessing interfaces. All parts and assemblies are created and virtually verified using PTC Creo CAD software.
Designs are subjected to material selection, thermal, vibration and tolerance analyses to meet product requirements. Mechanical design has extensive experience in selecting and verifying materials and has significant material analysis capabilities available. Thermal analysis is conducted with the Fluent IcePak CFD analysis package at the component, PCBA and system levels. ANSYS finite element analysis tools are used to virtually simulate vibration, deflection and structural stresses on both the PCBA and complete assembly. Tolerance analyses utilizing worst case and statistical methods are employed to verify a proper fit and appropriate clearances. Finally, designs are documented and verified to meet any industry standards required including, but not limited to:
- Drawing standards per ASME Y14.5M with Geometric Dimensioning and Tolerancing (GD&T).
- NADCA standards for Die Casting, UL, IEC 60529, IMDS and RoHS as applicable.
John Deere Electronic Solutions implements an integrated approach to product design and development, with clear evidence shown in the interaction of our PCB and mechanical design teams. PCB design is the integration of the mechanical and electronic disciplines. Utilizing design tools that are integrated electronically, the mechanical engineers design the outside enclosures of the structures using the PCB design team layouts. And the PCB designers use computer models created by the mechanical engineers to design the circuit boards. In addition, both teams work closely with on-site manufacturing engineers, process engineers, and manufacturing test engineers. This collaboration ensures an efficient, reliable design that can be cost-effectively manufactured on the equipment we have available. Once the PCB is designed, validated, and tested, design information is downloaded directly into the manufacturing equipment, which saves time, money, and reduces the chances for error.
It is also at this stage of design that our teams meet with our mechanical custom parts and component suppliers to ensure viability and availability of the quality parts we need to proceed with manufacturing the PCB. Once designs are finalized, they are subject to an intensive cross-functional design review before initiating the prototype build.
Software Design & Programming
Our software engineers design for quality using proven, ruggedized processes and applying Statistical Quality Techniques to identify and remove defects earlier in the software lifecycle. We have experience in developing product software for integrated or distributed systems, and use automated tools such as Software verification and Hardware in the Loop Simulations to ensure that our software functions efficiently, while seamlessly integrating into your existing systems. Code is written in C, and we are proficient with numerous operating systems, including RTXC, Nucleus and JD/OS; Standard OSEK; and Advanced WinCE, VxWorks and Embedded Linux.
Design For Manufacturability
A key component of John Deere Electronic Solutions ruggedized design is our dedication to Design For Manufacturability (DFM). Key design criteria are captured in a lessons learned database and design notes. Throughout the Product Delivery Process, engineering works closely with manufacturing, requiring phase gate reviews and process reviews to provide the best design for manufacturability and lowest cost solution for our customers. Having the process and manufacturing engineers involved in the product development process at John Deere Electronic Solutions enables a more efficient transition from product development to production.
Product Verification & Validation
After prototypes are built, they are subjected to an extensive Complete Verification Plan to verify circuit assumptions and ensure the design meets the designated requirements in the Product Requirements Document. Tests are customized to the specific project, and include a Bench Test and Electrical and Environmental Test, which are conducted by our Product Test Department.
Once prototypes have passed verification, they are provided to the customer for validation testing on the vehicle to confirm end-user performance. Once validation testing is confirmed as successful, the customer gives approval and production begins.