Two years ago, Kondo surprised everyone by releasing the KHR-1 humanoid robot kit with the RCB-1 controller. For the first time, a researcher, experimenter, or hobbyist, could build an affordable bipedal walking robot capable of very startling performance. Now, they are going to raise the performance bar drastically higher when the new Kondo RCB-3 robot controller hits store shelves in Japan next month. We were able to spend several hours hands-on with the new controller last weekend during a 'sneak-preview' briefing with the Kondo design engineers.
The RCB-3 was specifically designed to support high speed command execution, multi-tasking type performance, and master/slave operation. Servo control support includes PWM, ICS2.0, as well as H/L output.
To support real-time control, the RCB-3 incorporates two serial communication approaches - a high speed serial port capable of 115,200 bps communication, and a lower speed serial port for use with R/C type controls. The low speed interface is compatible with the existing KHR-1 controls.
In addition to 24 output ports to control servos and other similar devices, the controller features digital inputs as well as three analog input ports. Analog signal inputs can be scaled and mixed to trigger conditional program branching within the controller. This opens up a wealth of interface and autonomous behavior possibilities.
Servo ranges can also be scaled in software. For example, the 4014 servos we used during the briefing had an active range of approximately 4,000. By inserting a factor of 0.5 the effective servo range was mapped to 2,000.
The RCB-3 programming environment that runs under Windows 2000/XP, is also feature packed. Based on an easy to understand and use graphical interface, it's easy to create positions, tests, and branching conditions. To create a new position, all you have to do is click on the POS icon, then drop it in the programming window. Double clicking and right clicking bring up windows for you to adjust the servo positions and operating parameters.
Setting up a conditional branch is just as simple. Click and drop, then double-click to setup the conditions. Branching conditions include counters as well as external sensor inputs. It's also possible to scale and mix the inputs. Program flow is determined by clicking on a line icon, then using it to connect the positions and branching conditions you've already created in the programming window.
Want to change the starting position of a particular sequence? It's as easy as selecting and moving a little red flag icon that indicates the sequence starting point.
It's also simple to copy, edit, and reuse program/sequence segments. Just copy and paste them in the programming window, or pull them in from files.
The RCB-3 is what Kondo refers to as a HV, or high voltage (9-12 volt) device, and is primarily intended for use with their 400 series HV servos. However, the controller can easily be used with an existing, non-HV, KHR-1 robot using a booster designed by Kondo specifically for that purpose.
What can do you do with all that power and flexibility?
During the briefing, the Kondo engineers demonstrated a KHR-1 robot equipped with the RCB-3 controller. As you can see from the video below, the performance was pretty amazing. The robot responded immediately to commands. When the engineer swung the control joystick back and forth, the robot's arms tracked in real-time. It's easy to implement master/slave control strategies similar to those used by the Great Majingaa's control harness, only with the RCB-3 implementation you can do it all without the complicated harness.
When the engineers tilted the robot, it's feet tracked, or tracked as much as possible, parallel to the horizon. A good example of this is shown in the video when the robot does a smooth, almost effortless, cartwheel.
Of course, these are only simple examples. With the controllers conditional branching ability, and the fact that you can scale and mix inputs, users will quickly come up with much more complex behaviors. True autonomous behavior is definitely within reach. It's not a matter of 'if', it's only a matter of time - and the time frame is going to be extremely short after the new controller gets into the hands of robot experimentors.
Left: Kondo engineers explain the RCB-3 features and benefits.
Right: Each participant had a test bed that included the robot
controller, 4014 servo, and a PC so that we could actually
play with the controller and software in operation.
Creating a program/sequence with the RCB-3 software was very
straight forward and easy to understand using the graphical interface.
The robot controller software allows you to modify and adjust a
wide range of parameters and operating conditions.
Here's a short video clip showing some of the performance you can expect from the new robot controller:
Kondo plans to release the RCB-3 for sale in Japan during May, 2006 and is now busy finishing up the last items, like packaging, documentation, etc. to be able to go to market. Their MSRP target is 38,000 yen (without tax, in Japan). Needless to say, overseas availability, English documentation, and pricing, are not available at this time.
So, what's our impression?
Very positive. The RCB-3 is positioned to set a new standard for robot controllers while making a whole new generation of applications and solutions possible.
What else would we like to see?
Simple. While being able to experiment with the RCB-3 during the briefing was great, we weren't allowed to take it home with us. We're really looking forward to the opportunity to upgrade our KHR-1 to the new controller so we can give it a real work-out.
http://www.kondo-robot.com Kondo Robot website (Japanese)
http://www.rt-net.j p RT Corporation website - Robot kits, accessories, and training school (Japanese and English)