just a little unmanned boat that could be launched along the surface of the water to hit an enemy boat, detonate, and—hopefully for the launcher—sink the enemy boat.
Whitehead added some crucial innovations to the torpedo, and those innovations are what made it the first environment-reactive vehicle: it could keep to a constant, set depth under the surface and it could stay on a fixed course toward its target. Together, these were the makings of the first, crude guidance system, and the first time any inanimate object could really control its direction and compensate to maintain it, even with environmental inputs acting upon it.
To do this, Whitehead installed two pieces of equipment in the torpedo: a horizontal rudder controlled by pendulum balance (to maintain depth) and a hydrostatic valve (a one-way, pressure-relieving valve), and a gyroscope system driving a vertical rudder to keep it on course. These systems allowed the torpedo to control its path on two dimensions, with the third (forward travel) dimension provided by a three-cylinder radial-compressed air engine.
The pendulum-and-hydrostat control of depth is ingenious. A hydrostat senses the depth, but does not control the horizontal rudder directly; if it did the torpedo would oscillate around the desired depth without ever really settling. The pendulum swings based on the pitch of the torpedo, and is connected to the rudder control in such a way that it can dampen the oscillations, providing much steadier control over the depth of the torpedo. The pendulum-and-hydrostat device was such a big deal at the time that it was called the “Whitehead Secret,”4 and the same fundamental design was used all the way up to World War II.
The gyroscopic control for azimuth/yaw control came in 1895—prior to that, the azimuth (you know, direction, basically) was set with vanes by hand. The gyroscope in the Whitehead torpedo was spun up via a spring, and acted on the vertical rudder via gimbals. This kept the torpedo on a straight, direct path regardless of whatever forces (such as ocean currents) were acting upon it.
1925: Houdina American Wonder
The first conventional automobile to be driven without a person at the wheel was developed in 1925, but it’s really sort of a cheat. It wasn’t an autonomous car, but rather a remotely controlled car, so it was still driven by a human even though the human wasn’t inside the car.
Pictures of the car show it labeled as a “1926 Chandler,” which is sort of confusing, since it appears to have been demonstrated and in operation since 1925. The car, nicknamed the “American Wonder,” was built by an electrical engineer named Francis P. Houdina.
The way it worked was pretty straightforward: the car had a kite-shaped receiving antenna mounted on the tonneau, and electric motors under radio control to actuate the controls. It’s not entirely clear how many of the car’s controls were controlled by the motors or how the mechanisms worked. We do know the steering seems to have been accomplished with a belt or similar device around the steering shaft itself, because a poor grip on the steering column caused some excitement during a demonstration drive in New York in the 1920s.5
Here’s how the New York Times described it:
A loose housing around the shaft to the steering wheel in the radio car caused the uncertain course as the procession got underway. As John Alexander of the Houdina Company, riding in the second car, applied the radio waves, the directing apparatus attached to the shaft in the other automobile failed to grasp it properly.
As a result the radio car careened from left to right, down Broadway, around Columbus Circle, and south on Fifth Avenue, almost running down two trucks and a milk wagon, which took to the curbs for safety. At Forty-seventh Street Houdina lunged for the steering wheel but could not prevent the car from crashing into the fender of an automobile filled with camera men. It was at Forty-third Street that a crash into a fire engine was barely averted. The police advised Houdina to postpone his experiments, but after the car had been driven up Broadway, it was once more operated by radio along Central Park drives.6
It seems that, at a minimum, there were mechanisms for steering, starting the car, actuating the throttle pedal and brake pedal, and perhaps clutch and shifting. It’s possible they just left it in first or maybe second gear, though I think they’d need some degree of clutch actuation.
The thing seemed to work generally well enough for a proof of concept, and in the overall scope of autonomous vehicles the American Wonder proved that motors, servos (automatic devices with some form of error-sensing and correction), and similar mechanisms could be used to actuate conventional car controls in place of actual human limbs and hands. If we replace those radio signals from a human with signals from onboard cameras, sensors, and computers, you’ve effectively got the basics of how modern autonomous vehicles are built.
One fascinating footnote to this has to do with the inventor’s name: Houdina. As you probably already noticed, that name is an awful lot like Houdini, as in Harry Houdini, the famous illusionist and escape artist. Houdini was not the sort of person to take guff of any kind, ever, and he felt that Houdina was deliberately using a name that sounded like Houdini for the name of his company, Houdina Radio Control Co. Houdini didn’t seem to care that the man’s name was, in fact, Houdina, and was convinced it was all just some dirty ploy to capitalize on Houdini’s success and name recognition. Guys who escape from chains underwater don’t usually write tersely worded letters, and Houdini instead opted for the more direct method of going to Houdina’s office and trashing the place.
Houdini wrecked some furniture and an electric chandelier, and pitched what must have been a very exciting fit. Houdini was summoned to court regarding the incident, but no one from Houdina showed up, so Houdini got away scot-free with the perfect crime of chandelier damage.
1933: Mechanical Mike Autopilot
Even though at the moment autonomous control for cars is the hot topic of (admittedly geeky) conversation, it’s worth remembering that airplanes have been flying themselves, more or less, for decades. At first glance this may seem counterintuitive—aren’t aircrafts dramatically more complex than cars? How do they routinely employ self-piloting systems that automobile makers are still struggling with?
The answer is pretty evident when you think about it for even a slight moment, and chances are most of you already realized it while reading that last sentence. It mostly has to do with this one indisputable fact: the sky is really big and really empty. Obstacle avoidance isn’t really that pressing a concern in the air. The chances of a cyclist pulling out unexpectedly in front of you in the sky are exceedingly remote; even if one did, they’d have much bigger things to worry about than getting hit by a passing airplane.
It’s sort of counterintuitive, but the air is a pretty forgiving place in which to develop autonomous piloting systems, even when accounting for the fact that if anything goes wrong the equivalent process of pulling over to the side of the road ends in a fireball on the ground. The sky is vast and empty, and that’s why fairly crude devices like the Mechanical Mike Autopilot, the first really practical aircraft autopilot, were so successful.
Autopilots like Mechanical Mike and most of the ones that followed are self-piloting in that they can maintain a set course and heading (that is, the compass direction an aircraft is pointed) and altitude, but they’re not concerned with any real obstacle avoidance, unless you count the ground, which is, admittedly, a pretty significant obstacle.
