The metal charging snake prototype that Tesla recently demoed had me thinking some. While the snake is really cool, it looks mechanically complex and not at all inexpensive.
So this had me thinking about some ways that future Tesla vehicles could support automatic charging.
First, before the discussion goes off on wireless charging: It's simply nowhere near efficient enough, and probably won't be for another 10-15 years. So I was brainstorming a design for how vehicles could charge automatically, until the major disadvantages of wireless charging are eventually overcome.
This is not intended to be a retrofit for a Model S--I understand that this requires a modification to Tesla's skateboard design, but I think it is doable with relatively little pain.
Existing solutions involve the charging snake, or an articulated robot arm that plugs the existing connector into the car. While a robotic approach is certainly not too difficult to implement and could be decently reliable, it has a few disadvantages:
1. Cost. Such a system is not likely to be easily affordable.
2. Size constraints. A robotic system (snake or articulated robot) would require a certain amount of space next to the car to operate. Some charging situations may not have this space available.
3. Complex. Because it involves moving parts and control systems, it is inherently less reliable than a design with less moving parts.
So here's what I was thinking.
First, an existing side-mounted charge port is necessary on cars going forward, because there is so much infrastructure that uses the traditional plug approach. The proposal below would be ideal for home use (a garage or parking space) or for Superchargers.
It would work like this (excuse the horrible hasty Photoshop hacking, I am a mechanical engineer but lack artistic skills...especially when using a touchpad
:
On the underside of the car would be 5 flat, thin copper pads...maybe 6"x6". Each of these pads would be concealed behind a small sliding panel (could be plastic) on the bottom of the car to protect them from dirt and the elements. Each panel has a small lip at the front edge which you can grab and slide aft with your hand. When released it is closed by spring force.
Each of these pads on the car would be connected to +120V, -120V, Neutral, Ground, and one for handshaking:
On the garage floor would be 5 roller arms, each set up with a spring so that they naturally want to press up against the bottom of the car. The wheel itself is conductive and attached to, in this particular example, the +120V line:
As the car drives over these, the spring compresses to the proper height of the bottom of the car. As the roller approaches the lip on the sliding panel, it catches it and slides it back, exposing the copper charging pad. The spring force is enough to keep pressure on the lip to open it, and maintain good contact with the copper pad, but if the car keeps going the wheel will roll under the lip with no damage done.
So anyway, the car stops with the wheel contacting the pad and communicates to this device that it is now in park. A handshake process begins, and the device begins ramping up current. The current flows through the wheel, to the pad, and into the car.
This device could be screwed onto a garage floor, wires could be fed forward (so you don't drive over them), and there are probably several ways to "guide" the car so that the wheels are over the pad.
The point was that this type of thing could be implemented fairly cheaply and installed in any garage or parking space easily. It has few moving parts, requires little additional hardware on the car, and the guidance to get lined up wouldn't be too difficult. (The copper pads could be increased in size to, for example, 1 ft x 1 ft if needed.
Just initial brainstorming. Each wheel would need some sort of safety shroud, and weather considerations would need to be taken into consideration, but just wanted to through this initial brainstorming out there. I've gotta go for now.
So this had me thinking about some ways that future Tesla vehicles could support automatic charging.
First, before the discussion goes off on wireless charging: It's simply nowhere near efficient enough, and probably won't be for another 10-15 years. So I was brainstorming a design for how vehicles could charge automatically, until the major disadvantages of wireless charging are eventually overcome.
This is not intended to be a retrofit for a Model S--I understand that this requires a modification to Tesla's skateboard design, but I think it is doable with relatively little pain.
Existing solutions involve the charging snake, or an articulated robot arm that plugs the existing connector into the car. While a robotic approach is certainly not too difficult to implement and could be decently reliable, it has a few disadvantages:
1. Cost. Such a system is not likely to be easily affordable.
2. Size constraints. A robotic system (snake or articulated robot) would require a certain amount of space next to the car to operate. Some charging situations may not have this space available.
3. Complex. Because it involves moving parts and control systems, it is inherently less reliable than a design with less moving parts.
So here's what I was thinking.
First, an existing side-mounted charge port is necessary on cars going forward, because there is so much infrastructure that uses the traditional plug approach. The proposal below would be ideal for home use (a garage or parking space) or for Superchargers.
It would work like this (excuse the horrible hasty Photoshop hacking, I am a mechanical engineer but lack artistic skills...especially when using a touchpad
:On the underside of the car would be 5 flat, thin copper pads...maybe 6"x6". Each of these pads would be concealed behind a small sliding panel (could be plastic) on the bottom of the car to protect them from dirt and the elements. Each panel has a small lip at the front edge which you can grab and slide aft with your hand. When released it is closed by spring force.
Each of these pads on the car would be connected to +120V, -120V, Neutral, Ground, and one for handshaking:
On the garage floor would be 5 roller arms, each set up with a spring so that they naturally want to press up against the bottom of the car. The wheel itself is conductive and attached to, in this particular example, the +120V line:
As the car drives over these, the spring compresses to the proper height of the bottom of the car. As the roller approaches the lip on the sliding panel, it catches it and slides it back, exposing the copper charging pad. The spring force is enough to keep pressure on the lip to open it, and maintain good contact with the copper pad, but if the car keeps going the wheel will roll under the lip with no damage done.
So anyway, the car stops with the wheel contacting the pad and communicates to this device that it is now in park. A handshake process begins, and the device begins ramping up current. The current flows through the wheel, to the pad, and into the car.
This device could be screwed onto a garage floor, wires could be fed forward (so you don't drive over them), and there are probably several ways to "guide" the car so that the wheels are over the pad.
The point was that this type of thing could be implemented fairly cheaply and installed in any garage or parking space easily. It has few moving parts, requires little additional hardware on the car, and the guidance to get lined up wouldn't be too difficult. (The copper pads could be increased in size to, for example, 1 ft x 1 ft if needed.
Just initial brainstorming. Each wheel would need some sort of safety shroud, and weather considerations would need to be taken into consideration, but just wanted to through this initial brainstorming out there. I've gotta go for now
.
