DRS and Power Management under the hood of my Prius
I ended up with a Toyota Prius as my rental car for the week in San Diego. I’ve never driven a Prius before, and honestly, I’ve never really had an interest in the car until now. Like most, I knew that the Prius uses a Hybrid Synergy Drive (HSD) engine, but I had no idea about all the cool technology built into making the car so efficient. As a matter of fact, the Prius engine technology is in some ways similar to the Distributed Resource Scheduling and Power Management features of VI3 Enterprise.
According to wikipedia’s page about the HSD:
Hybrid Synergy Drive, (HSD) is a set of hybrid car technologies developed by Toyota and used in that company’s Prius, Highlander Hybrid, Camry Hybrid, Lexus RX 400h, Lexus GS 450h, and Lexus LS 600h/LS 600hL automobiles. It combines an electric drive and a continuously variable transmission. The Synergy Drive is a drive-by-wire system with no direct mechanical connection between the engine and the engine controls: both the gas pedal/accelerator and the gearshift lever in an HSD car merely send electrical signals to a control computer.
Wikipedia’s page for the Prius helps explain how it’s computer manages resources dynamically and uses power management features as well.
The computer program used in the Prius shuts off the engine when the car is stopped, is reversing, or is descending hills, thereby dramatically decreasing fuel consumption in city driving. The HSD’s on-board computer program determines when and how to use the engine, motor, or both to power the car and recharge the battery so as to maximize efficiency. Typically, a gasoline engine runs inefficiently at half-throttle, creating a choking condition called pumping loss, a major reason for the inefficiency of gasoline engines compared to diesels. The Prius minimizes pumping loss by using a high torque range as much as possible with the throttle fully open. Drive-by-wire throttle control technology and Toyota’s Hybrid Synergy Drive (a torque combiner, electric drive, and computer control) are essential to this engine control. In addition to the immediate benefit of reducing fuel consumption and emissions, stopping the gasoline engine also improves the performance of the catalytic converter, as the exhaust gases from an idling engine tend to cool the catalyst below its optimal temperature.
All of this cool technology was a challenge for me to get started, however. It took me 10 minutes of trying to start the car on my own in the rental car parking lot before I decided to get help. For those who haven’t driven a Prius yet, there is not a key ignition. You put your key fob (the same one for the remote door locks) in a hole in the dashboard, and then with your foot on the brake you press a big “start” button also on the dash right behind the steering wheel. Then you pres the accelerator to get the engine to turn over.
on May 8th, 2008 at 3:44 am
my company car is a Prius. I love it. it’s got everything onboard I need and is cheap(compared to other cars with the same size, in the Netherlands that is, and due to tax reduction)