Electric Vehicles and Electric Motors
June 7, 2009 by Steve Meyer
Filed under Commentary, Design, Green Energy, Green Engineering, INDUSTRY, Materials, Mechanical, Motion Control
A friend of mine finally got delivery of a Tesla Roadster. This prompted discussion of the drive train and the fact that Tesla has had to go from two speed transmissions which were failing to a transmissionless drive train. The ultimate mechatronic challenge, the electric car, is also a challenger in terms of the precise application of electric motor technology.
But it has to be said that the motor and drive solution for the electric car is not where the problem has to be solved. Any motor can be made to run an electric car. What is critical is how you apply it. The starting conditions require high torque at low speed and the running conditions require low torque at high speed. So, typically, what looks like a small 5 to 15 horsepower running requirement at full speed, becomes a 150 horsepower starting requirement depending on how quickly you would like to start. If you want to keep up with a Corvette, it uses 450 HP to start.
And this produces a lot of confusion. Why not use at 2 speed transmission to help the situation. Fine, but the ones that are available can’t handle the dynamic response of the electric motor.
Can electronics help this situation? Interestingly, yes. There is a control algorithm generally called vector control which allows you to manage the rotor torque and stator torque separately. By varying the phase angle between the two, like advancing and retarding the timing of a mechanical distributor cap on an internal combustion engine, you get different speed torque curves out of the motor. COOL! Is there any downside to this?
Yes. You need more current to produce more torque. That doesn’t change. So you have to be able to supply the current, and you have to be able to manage the heat. The heat is transitory since you only need the high current during starting, but it is best to have sophisticated software running to keep track of the RMS temperature of the motor. Lower operating temperatures mean longer life and reduced risk of demagnetizing the motor.
So, yes, you can run an electric car with a garden variety AC motor, and with good electronics, you can make it run fairly efficiently. With higher efficiency motors, the benefit is increased driving range from a given power source. High efficiency motors are frequently smaller and lighter weigh, but a weight savings in the motor of 50 or even 100 pounds is not that big a factor in the driving range when the curb weight of the vehicle is 3000 pounds.
Basically, its F=ma. If you can reduce the mass of the vehicle, you reduce the battery payload required to power the car. Aluminum space frames, like on the Prowler, have been studied by the car industry and can reduce curb weight by 400 pounds and reduce cost by 10% at the same time. We need to bring all the mechatronic leverage to the situation that we can, if we are going to make electric cars that make sense. Before its too late for Detroit.
Zuken Implements Mechatronics Design Strategy and Launches New 3D Modeling Solution
Munich, Germany and Westford, MA, USA – Zuken has made another step to strengthen the link between the electronics and mechanical design worlds by enabling parallel MCAD/ECAD design with a new collaborative software tool called Board Modeler. This forms part of company-wide strategy underway to deliver increased versatility and reliability between the mechanical, electrical, and electronics design disciplines. Board Modeler docks in Zuken’s electronic systems and PCB design suite CR-5000, allowing layout and mechanical engineers to work more closely together in synchronization from as early in the process as floor planning. In this way Board Modeler gives engineers the power to rise to the challenge of integrating PCBs into ever more mechanically complex products, while saving time through parallel working and the elimination of design re-work.
Layout Engineer Gets True 3D
For the first time, with Board Modeler the layout engineer can easily work in a 3D environment modeller. The true component shape is now visible, rather than just showing items approximated as a cuboid or cylinder (2.5D). This is achieved by performing 3D conversions of footprint data, importing parts made by MCAD, or by using Zuken’s online component database, which contains over 4.5 million accurately detailed 3D components. This enables the engineer to carry out floor planning, perform collision checks between the PCB housing, components or other PCBs; all working with the true 3D component shapes. Board Modeler also eliminates duplication of effort between electronic and mechanical design by permitting the layout engineer to import board outlines, pre-placed parts and obstacles directly from mechanical CAD tools. It also automatically back-annotates any board and placement changes, as board outline and restriction areas, into the PCB design, whether new or imported, so any required layout action, like re-routing, can be done easily. Industry standard neutral file formats, including STEP, ACIS , STL and IDF, are used to bridge the gap to virtually any mechanical CAD system.
This solution is the logical step forward from Zuken’s previous tools – EM Designer and EM Checker, and improves 3D capabilities through direct integration with board design solution CR-5000 Board Designer and manufacturing board panelling solution Board Producer, allowing users to handle more complex 3D data. This smooth integration also means board layout structures, with all the material properties and electrical constraints, can be exported via Board Modeler into numerical simulation tools for mechanical, electrical or thermal verification. Simulation results can then be easily back annotated into CR-5000 tools for design modifications.
Board Modeler also features a multi-board option that allows design verification of multiple boards and chassis on a multi-site global basis.
Supporting Mechatronics across Design Lines
By Ralph Raiola, Editor
Electronic Products
When it comes to mechatronics design, getting everyone on the same page is apparently more difficult than one might think. A recent Webcast sponsored by IBM titled “System Design: New Product Development for Mechatronics,” presented research about the challenges and pressures faced when designing in a mechatronics environment.
Energy Stimulus Debate
February 8, 2009 by Steve Meyer
Filed under Commentary, Design, Green Engineering, Networks, Solar Power
As “We the People” wait for Congress to do something to stimulate the economy we are flooded with information about “Green Initiatives” as part of the stimulus strategy. And its really easy to get dragged along with the tide of enthusiasm. After all, the electric car has languished in the shadows for over 70 years since the Baker company closed its doors. So the idea of re-inventing even a small part of the automotive industry in the US is very appealing during a difficult period in our history.
We all share the concern that unemployment is up and many areas of the economy are slow. But let’s be sure that when the government says its going to spend our money, that the decisions are based on sound strategy. Maybe government spending money that it doesn’t currently have isn’t such a great idea. Read more
The Tools, They are a Changing’
December 14, 2008 by Steve Meyer
Filed under Commentary, Design, Simulation
(regarding the title, just think Bob Dylan’s “The Times They are a Changin”)
Just as Computer Aided Design, CAD, has revolutionized the design process, it is growing in capability and impacting many other arenas of engineering. The first major extensions to CAD were integration of Finite Element Analysis, the ability to analyze loads on the parts being created. And certainly, if the design software can model the complex aspects of loading, then animation of part motion can’t be a far reach. And that’s the case today. Read more
Robotic Kits for “Do-It-Yourself” Packaging System Design
October 17, 2008 by admin
Filed under Design, Mechanical, Robotics, Solar Power
Modular programming and articulating arm kits let you design your own robotic-based packaging system.
By Tom Jensen
Engineering Manager
ELAU Inc., a Company of Schneider Electric
For many years two factors gave robot designers and manufacturers a lock on developing equipment for the packaging market: patents and the specialized kinematic knowledge required to program robotic motion. While the robotic arms were under patent, the controls held the unique motion algorithms needed to handle the complex path planning, blending, and resolution of multiple trajectories to the same point. Thus, robot articulating arms and specific controls were exclusive to robot developers.
Read more
Low-cost photosensor apes eye’s response
August 14, 2008 by Bryan DeLuca
Filed under Design, Robotics
The S10604 chip-on-board-type illuminance sensor displays a spectral response close to human eye sensitivity, with reduced sensitivity to IR light. Priced under $0.80 each in hundreds, the RoHS-compliant sensor suits energy-saving brightness control applications from large-screen TVs to cell phones LCDs.
Designed to reduce effects from 940-nm LEDs like those used in remote controls, the S10604 also features minimal error due to color-temperature variations of sources such as fluorescent and incandescent lamps. The device comes in a 2.0 x 1.25 x 0.8-mm package that suits mass-production pick-and-place operations. (From $0.77 ea / 100 to 999 — available now.)
Hamamatsu, Bridgewater, NJ
Information 800-524-0504
http://sales.hamamatsu.com
Development platform has FPGA, ARM 922
July 22, 2008 by Bryan DeLuca
Filed under Design, Robotics
The RC240 development platform aids the design and optimization of high-performance algorithms using an FPGA and an ARM 922T core for digital entertainment, communications, and robotics applications. It includes a 4-Mgate Virtex-4 FPGA, 12 Mbytes of pipelined SRAM, 128 Mbytes of SDRAM for FPGA use, and 128 Mbytes of SDRAM for ARM CPU use.
Power-dense battery targets robotics
July 22, 2008 by Bryan DeLuca
Filed under Design, Robotics
The seven-cell 25-V 2.9-Ah 73-Wh PG3665A29 high-power-density smart lithium-ion batteries packs are for robotics and 24-Vdc motor applications. The battery provides the capability to continuously deliver 20 A with 30-A peaks making them appropriate for applications that have high inrush currents at startup and shutoff.
5 Design Challenges and Solutions for Machine Builders
Machine builders can virtually prototype their machine control systems with LabVIEW and the NI SoftMotion Development Module for motion profile generation as well as mechanically simulate and detect collisions with SolidWorks and COSMOSMotion.
Intense competition is putting pressure on machine builders to deliver machines with higher throughput, reduced operating cost, and increased safety.
By Nipun Mathur, National Instruments
Faster, better, cheaper, safer is the name of the game for machine builders. For this reason, today’s machine builders have switched from rigid, single-purpose machines – relying purely on mechanical gears and cams – to flexible multipurpose machines by adopting modern control systems and servomotors.
Although these improvements have made machines more adaptable, they also have introduced a significant amount of complexity to the machines and subsequently to the machine design process. Along with designing the mechanicals, machine builders now incorporate control logic, human machine interfaces (HMIs), networking, and machine condition monitoring systems into their designs. The added complexity has created inefficiencies in the machine design process that lengthen design time and increase design cost.
Solving this multidisciplinary engineering problem requires improvements in three key areas – development techniques, design tools, and embedded control technology. The term mechatronics is gaining popularity as a way to describe this evolution. It represents an industry-wide effort to improve the design process by integrating the best available development practices and technologies to streamline machine design, prototyping, and deployment. A mechatronics-based approach can lower the risks associated with machine design and meet the following five key challenges that machine designers face today. Read more
