Robo Claw Motor Controller NEW

There has been much written about this but I thought I would add new info gained today.

I called Orion in California and spoke with Nathan (714-442-8689). He is very familiar with the JRK12 and it's limitations as to voltage and amperage.

He indicates that the Robo Claw could be used easily if someone would write the software for the interface to SimTools.

In addition, they will be announcing new products next month, MCP260 and MCP230 with up to 60 volt and 120 Amps per channel (2 channels). Nathan indicated that if five XSimulator community members were interested in "beta" development for Racing Sims using these boards, then Orion would write the interface to make the Robo Claw compatible with the JRK12 code already written.

I like the idea of a "layman's interface" to a motor controller that would allow bigger motors and or motors with higher voltage. So this is of interest to me and I would be happy to be one of the five to incorporate the new RoboClaw into a new 2DOF with Traction Loss I would build.

Any comments or interest???

Also, please feel free to communicate with Nathan directly. Here is a chance to have a product developed specifically for our application.

If software can be written to control it to run Simtools, I am interested.

Nathan at Orion indicated that whoever wrote the SimTools software code to interface with JRK12 could also write "similar" code for RoboClaw and present products would work but user friendly interface of the JRK12 would not be same. The "new" here is that on the new MCP260 (120 Amp per channel) and MCP230 (100 Amp) products he would be willing to "invest" the coding time to make their product interface with SimTools in the same user friendly way as the JRK12.

I am not a programmer, but I can follow "logical" directions so GUI interfaces have a lot of appeal to me. Plus these boards look quite robust and give lots of flexibility. The more research I've done, from a mechanical engineering point of view, the more appealing DC motors appear to have big advantages over linear actuators---more design flexibility and lower cost. I just think we are pushing the envelope using 12Volt motors with 15A continuous and 30-50A stall amperage. These Robo Claw boards will run double that while running cooler and longer.

Who is/are the person/s who write code for the SimTools interfaces? (JRK12, Arduino, and SCN5)

As I can remember from old conversation http://www.xsimulator.net/community/threads/roboclaw-motor-controller-investigation.5273/
there were many points arisen. Close loop control, power supply....

As Roboclaw is designed to recharge the battery of autonomous robots,
what Nathan said about current sent back to recharge the battery?

Can it be used with server PSU?

The battery recharge is when used by a "coasting" robot to use the regenerative power from the DC motor---it would not be used for our application. It can be used with an external power supply.

It can be used with a potentiometer for position control.

Essentially, it would do what the JRK12 does and more. I think it could be controlled by an Arduino, but with the right interface code in SimTools, it could run without the Arduino--like the JRK.

So the only thing missing here is the code for the USB interface between Sim Tools and the Robo Claw board.

Racing Mat--are you not a programmer? Is this code thing like a days work for someone with skills and experience??..in other words not me!

SEE BELOW from the site http://www.orionrobotics.com/RoboClaw-HV-2x60A-Motor-Controller-60V_p_334.html


Description
The RoboClaw HV 2x60A motor controller 60V is an extremely efficient, versatile, dual channel synchronous regenerative motor controller. It can supply two brushed DC motors with 60 Amps continuous and 120 Amps peak. The Roboclaw HV 2x60A 60V also support main battery voltages upto 60v.

RoboClaw supports multiple sensor inputs including dual quadrature encoders with up to 19.6 million pulses per second, potentiometers and absolute encoders.With dual quadrature decoding you get greater control over speed, velocity and direction. Automatically maintain speed and direction even if the load changes. With the ability to use potentiometers you can easily create giant servo systems and control them from any of RoboClaw's interface modes.

The RoboClaw motor controller comes equipped with several built in modes to controller your motors. Use standard RC receiver/transmitter, serial devices, analog sources or a microcontroller such as an Arduino.

As a synchronous regenerative motor controller RoboClaw will charge the attached battery during a slow down or breaking action. With the advance circuitry it can also change direction during full throttle without damage! RoboClaw also incorporates a lithium cutoff mode which protects your batteries from damage. Get the power to win your next robotics competition!

Downloads

• Data Sheet

• Python Example for Raspberry Pi, OSX, Linux, Windows

• IonMotion Setup Application

• Roboclaw C# Class Library Source Code

• USB Roboclaw WIndows Driver

• Arduino Library and Examples

Features

• Supports up to 60V

• USB Interface

• 3.3V Compliant Outputs

• 5V Tolerant Inputs

• Quadrature Encoders

• Absolute Encoders

• Position and Velocity Control

• Encoders Supported in all Modes

• High Resolution Current Sense

• High Speed Direction Change

• Battery Level Monitoring

• Dual Channel Quadrature Decoding

• Dual 19,600,000 PPS Per Channel

• Thermal Protection

• Regenerative Breaking

• Serial, RC or Analog Control

• Easy to Use

• Can be Bussed

if available and SimTools compatible, me too. Thanks @stroutmail for putting one's back into our community.

The problem is not finding someone that can write an interface for simtools. The problem is that their provided documentation sucks at best! I have looked it over extensively. If you already know how to program it, then their documentation does serve as a reference I suppose but that’s about all its good for imho! Next time you talk with him ask how he expects those not familiar with their products already to "easily" learn how to write code for them, through osmosis?

What we need to know is exactly how to put the roboclaw into position mode and exactly what this all means and how to set the values correctly.

61 - Set Motor 1 Position PID Constants

The RoboClaw Position PID system consist of seven constants starting with P = Proportional, I=
Integral and D= Derivative, MaxI = Maximum Integral windup, Deadzone in encoder counts, MinPos = Minimum Position and MaxPos = Maximum Position. The defaults values are all zero.

Send: [Address, CMD, P(4 bytes), I(4 bytes), D(4 bytes), MaxI(4 bytes), Deadzone(4 bytes), MinPos(4 bytes), MaxPos(4 bytes)

Position constants are used only with the Position commands, 65,66 and 67 and RC or Analog
mode when in absolute mode with encoders or potentiometers.


62 - Set Motor 2 Position PID Constants

The RoboClaw Position PID system consist of seven constants starting with P = Proportional, I=
Integral and D= Derivative, MaxI = Maximum Integral windup, Deadzone in encoder counts, MinPos = Minimum Position and MaxPos = Maximum Position. The defaults values are all zero.

Send: [Address, CMD, P(4 bytes), I(4 bytes), D(4 bytes), MaxI(4 bytes), Deadzone(4 bytes), MinPos(4 bytes), MaxPos(4 bytes)

Position constants are used only with the Position commands, 65,66 and 67 and RC or Analog mode when in absolute mode with encoders or potentiometers.

65 - Drive M1 with signed Speed, Accel, Deccel and Position

Move M1 position from the current position to the specified new position and hold the new position. Accel sets the acceleration value and deccel the decceleration value. QSpeed sets the speed in quadrature pulses the motor will run at after acceleration and before decceleration. The command syntax:

Send: [Address, CMD, Accel(4 bytes), QSpeed(4 Bytes), Deccel(4 bytes), Position(4 Bytes), Buffer(1 Byte), Checksum]

66 - Drive M2 with signed Speed, Accel, Deccel and Position

Move M2 position from the current position to the specified new position and hold the new position. Accel sets the acceleration value and deccel the decceleration value. QSpeed sets the speed in quadrature pulses the motor will run at after acceleration and before decceleration. The command syntax:

Send: [Address, CMD, Accel(4 bytes), QSpeed(4 Bytes), Deccel(4 bytes), Position(4 Bytes), Buffer(1 Byte), Checksum]

And we need to know if we can still use pots with this method or if it can only be done using encoders.

I am told and it is written in their manual that analog position control with potentiometer is programmable. They give example of code for encoder using arduino..I will ask for simple example code for pot like move motor 1 forward to position 4.5 V. Seems like documentation is for robot makers...to a non programmer like me the documentation seems comprehensive if not illustrative..seems like we need to get them familiar with our application.

Perhaps we could share the Arduino code we use now with him and ask if he could adapt it to his board?

Yes, but their manual says one thing here and a different thing there in places so I don’t know which to believe. One place says you can use pots and the other says encoders with position mode. But if they can emulate the jrk properly, problem solved anyway!
And the documentation reads more like a dictionary to me. It doesn't really explain how to put things together, only a definition. I guess that's what the examples are for but as I recall, there is not an example of what we need.

And also, if I recall correctly, analog mode is for control with a joystick. To use that mode you must send a voltage signal to it. You could do that with a microcontroller but not from simtools directly. We need serial mode for that!

My understanding is the voltage 0-5 volt comes thru the pot..just like on the jrk and arduino.

I looked it up to be sure.

Analog mode is a type of input mode but its not the same as using pots for feedback.

And then there is this:

Also, please note where underlined above that it says analog mode can not use encoders and then later says analog mode can be used with encoders! WTF!

I think the applicable section is Serial Packet and Advanced Serial. It gives examples for encoders but does not for pots. I will ask for an example if using pots.

Also commands 91 thru 93 seem applicable...they seem to refer to a pot as an analog encoder rather than a PID. How to calibrate is not addressed. Please keep in mind that Nathan suggested that if there was enough interest from 5 or more users, he would create code and documentation JUST FOR US.

Sounds good man! Thanks for taking the time to do this too! We stalled when investigating the roboclaw before because nobody bothered to call to get better information!

I did the groundwork calling Dimension Engineering about the kangaroo to get it going with simtools so I hoped someone else interested in the roboclaw would take on the challenge.

From my understanding from your tutorial on the Kangaroo and Dimension Engineering Motor Controller, you can use larger motors without having to understand ARDUINO, BASIC or C++ programming. So I guess the only thing Robo Claw would offer is if their "interface" was even more "user friendly"??? Or just as an "Alternative" solution. Looks like the Kangaroo and Sabertooth 2X60 is a pretty good solution for either a Joyrider or Seat Shaker? ($200 to control two (2) motors.)

I have a Kangaroo w/ Sabertooth 2x25. They are very nice, albeit the newer 2x32 is definitely preferred (they've made many enhancements, not just power). You'd need one heck of a power supply / motor combo to warrant the 2x60. They can handle up to 30V, I use 24V.

That said, these new Robo Claws look pretty amazing. 60V, assuming your PSU and motors support it, mean much thinner wiring for the same wattage. Thin wire is much more flexible and usually a great deal less expensive. 25A would do 2HP, one heck of a sim...

60V PSUs with any real amperage are not common. It might be easier and cheaper to use batteries, albeit certainly less convenient. Still, I like the concept of these controllers.

I have spoken with Nathan at Basic Micro/Orion and passed on everyone's comments. I also started a thread on their forum which Nathan responds to. The "new" MCP products coming out in a month or so will have a user programmable interface whereas the present products require changes to firmware. In any case, the only reason the Analog Encoder==Potentiometer==POT is not better documented is that the feature was added after the documentation was written.

http://forums.basicmicro.com/topic10280.html?sid=033710df72ab81854fdb3a33276c67b1