Microsoft Robotics Blog : Technical Information

Recorded talk : Microsoft Robotics Studio -- An Introduction

JosephFernando — Fri, 29 Feb 2008 20:43:00 GMT

If you are interested in an introduction to Microsoft Robotics Studio you can find Vlad’s talk here.

With this talk you will learn:

· How to get started with Microsoft Robotics Studio

· How to easily create services for a wide variety of robot hardware using the Visual Programming Language

· How MSRS makes Asynchronous Programming easy with the Concurrency and Coordination Runtime (CCR) which simplifies programming to handle asynchronous input from multiple robotics sensors and output to motors and actuators

· How the Decentralized Software Services (DSS) application model makes it simple to access, and to respond to a robot’s state, using a Web-browser or Windows-based application thereby allowing real time monitoring of robotic sensors and response to motors and actuators.

Also you can find a collection of other interesting technical talks by Vlad Vinogradsky, Architect Evangelist, here.

Thanks

Joseph Fernando

Performance considerations when using enumerable types

JosephFernando — Fri, 19 Oct 2007 04:50:00 GMT

We’ve observed a high CPU utilization when using enumerable datatypes with binary serialization/intranode interaction. Performance degradation is most noticeable when a List (or Array) contains many items and/or the frequency of use is very high. The root cause for this is in the conversion of each item in the list to XML prior to binary serialization in our proxies. This regression will be fixed with the next update.

For now you can use the following workaround.

1. Identify each class which is itself a member of a list or array.
2. In the definition for this class, inherit from Microsoft.Dss.Core.IDssSerializable, and implement stubs for the members as shown below.

using Microsoft.Dss.Core;
...

[DataContract()]
public class MySensorState
{
[DataMember]
public List<MyListElement> MyLists;
}

[DataContract]
public class MyListElement: IDssSerializable
{
…

#region IDssSerializable Members

object IDssSerializable.Clone()
{
throw new Exception("The method or operation is not implemented.");
}

void IDssSerializable.CopyTo(IDssSerializable target)
{
throw new Exception("The method or operation is not implemented.");
}

object IDssSerializable.Deserialize(System.IO.BinaryReader reader)
{
throw new Exception("The method or operation is not implemented.");
}

void IDssSerializable.Serialize(System.IO.BinaryWriter writer)
{
throw new Exception("The method or operation is not implemented.");
}
#endregion

}

Using the CCR and DSS beyond Robotics

George Chrysanthakopoulos — Sat, 10 Mar 2007 00:02:00 GMT

"Can I use the CCR for something other than Robotics?"

The answer is yes, and same applies to our distributed runtime (DSS). We think robotics is a very interesting application for autonomous software, for software that coordinates inputs with outputs. Coordination, responsiveness, dealing with partial failure is what the CCR helps you with which tends to be what most software needs.

Note that commercial use of the CCR and DSS falls under our commercial license so please read about it at [1]. But our license does not restrict you to use the runtime only on robots, which is a common misunderstanding. You can use it for anything, and the CCR has no dependencies on any of the robotic specific samples or even on the services runtime (DSS).

More on the CCR and how it can easily express patterns from a variety of other paradigms (like futures, state machines, data flows, event based synchronization, locks, joins, etc) will come in future posts.

If you like to discuss the CCR please use our newsgroup for now, since that is where all the active threads are taking place.

If you are using CCR or DSS for an application outside robotics then please tell us about it by posting a message to our Newsgroup. Even if we may not be able to provide support for such uses we would love to hear about it.

[1] http://msdn.microsoft.com/robotics/downloads/EULA_Com/default.aspx

Change of Protocol Name: WSAP to DSSP

JosephFernando — Wed, 09 Aug 2006 08:31:00 GMT

In our first Community technical preview we introduced a ‘SOAP’ based protocol called "WSAP". This protocol has now been renamed to "DSSP" which stands for Decentralized Software Services Protocol. DSSP defines a set of state-oriented message operations for retrieving, manipulating, and subscribing to structured state changes in a service.

The DSSP specification can be found at: http://purl.org/msrs/dssp.pdf

With the August 2006 Community Technical Preview we’ve included a conversion tool that will help you migrate your existing projects to the current release. Once you install the new setup refer to the installed link for additional information: Start/ [All]Programs / Microsoft Robotics Studio (August 2006) / Migrating Microsoft Robotics Studio Projects.

-Joseph

Test suite

JosephFernando — Tue, 08 Aug 2006 02:55:00 GMT

As part of the Microsoft Robotics Studio August 2006 CTP, we provide a small test suite that can be used to verify that various parts of the Studio behave as expected. For platforms or languages not mentioned on our download page you can try and see if the basic functionality is ok by installing the Studio and running the tests. The test suite is in the form of a few VBScripts that can be executed directly from a command prompt without any parameters. From a "Microsoft Robotics Studio Command Prompt" you can find the scripts by going to this folder:

cd test\Dss\BVT

You can run any of the scripts using the Windows Scripting Host, for example

cscript BVT_Intranode.vbs

When running this particular script you will see three Command Prompts popping up and if the script terminates correctly you will see something like this in the Command Prompt where you started:

Microsoft Robotics Studio: C:\Microsoft Robotics Studio (August 2006)

Terminating running DssHost processes

Starting the first node of the BVT intranode test

Starting the second node of the BVT intranode test

BVT is running... for most recent results, see C:\Microsoft Robotics Studio (August 2006)\test\Dss\BVT\BVT_Intranode.output.txt

BVT passed successfully!

Terminating running DssHost processes

You can find the most recent result of the test suite in the output.txt file. In addition, you can see the debugging output generated by the Studio using a tool such as "DebugView" from SysInternals™. The other scripts function in a similar manner. If you find problems then we are interested in hearing about it on the Microsoft Robotics Studio newsgroup.

WSAP

JosephFernando — Tue, 27 Jun 2006 11:23:00 GMT

Microsoft Robotics Studio (MSRS) uses a SOAP based protocol called WSAP. With WSAP an application is defined as a flexible composition of lightweight entities called services. Through operations defined by WSAP services can be created, manipulated, monitored, and destroyed repeatedly over the lifetime of an application.

WSAP defines a set of state-oriented message operations for retrieving, manipulating, and subscribing to structured state changes in a service. WSAP can be thought of as an extension to HTTP and is expected to be used as an addition to existing HTTP infrastructure.

For more information please see:

http://download.microsoft.com/download/0/9/3/0936d9a3-0d03-4174-97db-1c75d0ef44aa/WSAP.doc

Microsoft Robotics Studio Runtime

JosephFernando — Tue, 27 Jun 2006 11:00:00 GMT

A typical robot perceives it’s surrounding through an array sensors and interacts with its environment by orchestrating the reaction across one or many actuators. For a decent operation these activities must be performed simultaneously and possibly across multiple compute units. Though this may sound simple, concurrent processing of sensory input, making decisions and controlling the actions can get fairly complex very quickly when bound to classical threading and synchronization mechanisms.

Microsoft Robotics Studio (MSRS) simplifies the orchestration and the distribution of computation by the introduction of service-oriented application architecture and a light weight runtime. This architecture facilitates the composition of structured applications through the assembly of software pieces – called services that provide device level abstraction, isolation, concurrency, distribution and failure tolerance. In this environment applications are a collection of services that orchestrates the interaction between these services by implementing the program logic.

To execute these concurrent and distributed applications the runtime offers the following:

A Concurrency and Coordination Runtime (CCR):

CCR enables the coordination of messages without the use of threading, locks, semaphores, etc. The CCR is based on asynchronous message passing and provides an execution context for services including a set of high-level primitives for synchronizing messages.

Decentralized System Services (DSS):

DSS provides a service hosting environment and a set of basic services facilitating tasks such as debugging, logging, monitoring, security, discovery, and data persistence.

The interested reader is referred to the following technical article:

http://msdn.microsoft.com/robotics/getstarted/runtime/default.aspx