BRAT Biped SEQ Tutorial v1.06XE

> <a href="https://wiki.lynxmotion.com/info/wiki/lynxmotion/download/servo-erector-set-robots-kits/ses-v1-robots/ses-v1-bipeds/brat-biped-seq-b/WebHome/minibipd.zip">minibipd.zip</a></td>

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Image of Biped BRAT.</td>

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I. BRAT Configuration

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<td valign="top" align="left">Step

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1.

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Install the SSC-32 Visual Sequencer. Read the Sequencer's manual. This

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tutorial is not meant to replace the manual! Connect the SSC-32 to the

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serial port and apply power. The green LED should light and stay on until

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it receives a valid serial command. Run the Visual Sequencer program.

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Step 2.

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The first step in configuring your robot is to position all the servos to

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mid-position. This is a quick way to ensure the robot was constructed

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properly. Click on "All=1.5mS" in the upper left corner.

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Figure 2.</td>

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<td valign="top" align="left">Step

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3.

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Click the "Test" button.</td>

Figure 3.</td>

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<td valign="top" align="left">Step

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4.

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Place the robot in a position as close to neutral as possible. Click

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"Yes" and the robot should go to and hold the neutral position.

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Your robot should resemble figures 4-2 and 4-3. If the joints are off by

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more than 15° you may have made an error in assembly. To correct this,

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you remove the center screw from the round servo horn, pull the servo horn

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off the servo, rotate until it's aligned, then reattach the servo horn.

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When you are done, click on the

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"Stop" then "Exit" buttons.

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Figure 4-1.</td>

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Figure 4-2.

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Figure 4-3.</td>

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<td valign="top" align="left">Step

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5.

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Click on "SSC-32" in the upper left corner. This process

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configures the software to the servos in your robotic assembly. To do

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this, the servos' neutral, min, and max positions are defined and the

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actual angles each joint can achieve are entered.

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Take time to do an accurate

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configuration! Your robot will only perform as well as the accuracy of the

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configuration file it's using. In other words, sloppy configuration will

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make a sloppy robot when sharing projects.

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Figure 5.</td>

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<td valign="top" align="left">Step

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6.

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Each servo you configure must first be enabled. You simply click on the

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Enable checkbox. You can move the servo by adjusting the slider bar.

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You will enable the servos one at a time

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as you configure them.

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Figure 6.</td>

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<td valign="top" align="left">Step

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7.

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Channel 0 is for the BRAT's ankle on the right leg. Move the slider for

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servo 0 until the servo is at a 90° angle as shown. Note, the mouse's

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scrollwheel or keyboard's arrow keys can be used to make fine adjustments.</td>

Figure 7.</td>

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<td valign="top" align="left">Step

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8.

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Right click on the slider and select "Set position as neutral (0°)"

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from the menu.

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Note, you can see the actual servo pulse

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length in microseconds in the "Position" box on the left. This

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can be helpful to make a pulse offset table for experimenting with BASIC

programming.

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Figure 8.</td>

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<td valign="top" align="left">Step

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9.

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Move the slider for servo 0 until the servo is at a 45° angle as shown.

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Right click on the slider and select

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"Set position as min" from the menu as shown in Figure 9-2.

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Adjust the "Min Deg" box to say

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"-45°" as shown in Figure 9-3.

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Figure 9-1.</td>

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Figure 9-2.

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Figure 9-3.</td>

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<td valign="top" align="left">Step

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10.

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Move the slider for servo 0 until the servo is at an 84° angle as shown.

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Right click on the slider and select

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"Set position as max" from the menu as shown in Figure 10-2.

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Adjust the "Max Deg" box to say

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"84°" as shown in Figure 10-3.

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Move the slider back to 0° before going

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on to the next servo.

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Figure 10-1.</td>

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Figure 10-2.

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Figure 10-3.</td>

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<td valign="top" align="left">Step

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11.

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Channel 1 is for the BRAT's right knee. Adjust and set the neutral (0°)

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position with the knee straight as shown in Figure 11-1. Adjust and set

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the min and max positions as shown in Figure 11-2 and 11-3. Note, you do

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not have to change the angles because the knee can reach +/-90°.

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Move the slider back to 0° before going

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on to the next servo.

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Figure 11-1.</td>

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Figure 11-2.

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Figure 11-3.</td>

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<td valign="top" align="left">Step

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12.

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Channel 2 is for the BRAT's right hip. Adjust the hip as shown in Figure

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12-1 and set the neutral (0°) position. Adjust the hip as in Figure 12-2

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and set the minimum (-90°) position. Adjust the hip as in Figure 12-3 and

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set the maximum (45°) position. For clarity, the knees were bent in

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Figure 12-3.

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Move the slider back to 0° before going

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on to the next servo.

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Figure 12-1.</td>

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Figure 12-2.

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Figure 12-3.</td>

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<td valign="top" align="left">Step

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13.

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The robot's right side is now configured. You can now configure the

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robot's left side. Click on the "Bank 3" button to gain access

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to channels 16-23. Channel 16 is the right ankle, 17 is the right knee,

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and 18 is the right hip. Configuring these channels is identical to

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configuring channels 0-2 with one exception: After you are done with the

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normal configuration, you must click on the "Reverse" checkbox

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for these three channels! Make sure all servos are set to 0° (home) and

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save your work. For this robot, "home" position is with all the

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servos set to their 0° position. However, any position you leave the

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sliders in when you save the configuration is how the robot will look when

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you start Sequencer. In other words, "home" position does not

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have to be the 0° position, that's just what we used. Save your work. The

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.cfg file will need to be loaded each time you run the program. If you

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only have one robot to set up, save over the "ConfigSSC32.cfg"

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file. However, if you plan on using the sequencer with more than one

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robot, then input a new file name, such as "BipedBRAT.cfg" It's

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important that you save these files in the install directory, default

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C:\Program Files\Sequencer_SSC-32\</td>

Figure 13.</td>

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<td valign="top" align="left">Step

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14.

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Now we're going to import a pre-made project. This will enable you to use

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other people's projects on your robot.

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Download <a href="https://wiki.lynxmotion.com/info/wiki/lynxmotion/download/servo-erector-set-robots-kits/ses-v1-robots/ses-v1-bipeds/brat-biped-seq-b/WebHome/minibipd.zip">this

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zip file</a>. It contains several projects. Unzip it into the SEQ install

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directory. By default, it is C:\Program Files\Sequencer_SSC-32\

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Click on "Project" in the upper

left corner.</td>

Figure 14.</td>

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<td valign="top" align="left">Step

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15.

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Click on "Import," then select "biped6-long stride.csv"

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and click "Open," then "OK."

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Enter a project name or leave the

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default, then click "OK." You should see an "Import

success" message.

Click "Exit."

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Figure 15.</td>

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<td valign="top" align="left">Step

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16.

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Now for some fun! Let's make that robot walk!

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Click on "Sequencer" as shown

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in Figure 16-1.

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From the drop down menu in the project

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section, select "biped6-long stride."

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In the Play menu, click on "Project

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Loop" as shown in Figure 16-3. Caution, the robot will start moving

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immediately. To stop the robot, click on the black "stop" or

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"pause" buttons.

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If everything went well, your robot

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should have walked across the table. If it appears that the legs are

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moving in the same positions, you may have forgotten to reverse the servos

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on the robot's left side.

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Figure 16-1.</td>

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Figure 16-2.</td>

Figure 16-3.</td>

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<td valign="top" align="left">Step

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17.

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Refer to Table 17 for a list of the projects included in the zip file and

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a video link when available.

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After you're comfortable with playing

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projects, you can consult the Sequencer manual for more information on how

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to create your own. Remember to send us images and videos of your cool

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projects so we can publish them online!

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<td align="center" bordercolor="#808080" bgcolor="#C0C0C0">Project

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File</td>

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<td align="center" bordercolor="#808080" bgcolor="#C0C0C0">Video

Link</td>

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<td align="center" bordercolor="#C0C0C0" bgcolor="#FFFFFF">Balance

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on Ankle</td>

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<td align="center" bordercolor="#C0C0C0" bgcolor="#FFFFFF"><<a href="https://www.lynxmotion.com/images/video/bp6srv04.mpg">Video</a>></td>

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<td align="center" bordercolor="#C0C0C0" bgcolor="#FFFFFF">Balance</td>

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<td align="center" bordercolor="#C0C0C0" bgcolor="#FFFFFF"><<a href="https://www.lynxmotion.com/images/video/bp6srv06.mpg">Video</a>></td>

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<td align="center" bordercolor="#C0C0C0" bgcolor="#FFFFFF">Get

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up from Back</td>

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<td align="center" bordercolor="#C0C0C0" bgcolor="#FFFFFF"><<a href="https://www.lynxmotion.com/images/video/bp6srv05.mpg">Video</a>></td>

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<td align="center" bordercolor="#C0C0C0" bgcolor="#FFFFFF">Get

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up from Front</td>

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<td align="center" bordercolor="#C0C0C0" bgcolor="#FFFFFF"><<a href="https://www.lynxmotion.com/images/video/bp6srv01.mpg">Video</a>></td>

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<td align="center" bordercolor="#C0C0C0" bgcolor="#FFFFFF">Headbutt</td>

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<td align="center" bordercolor="#C0C0C0" bgcolor="#FFFFFF"><<a href="https://www.lynxmotion.com/images/video/bp6srv07.mpg">Video</a>></td>

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<td align="center" bordercolor="#C0C0C0" bgcolor="#FFFFFF"><<a href="https://www.lynxmotion.com/images/video/bp6srv03.mpg">Video</a>></td>

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<td align="center" bordercolor="#C0C0C0" bgcolor="#FFFFFF">Long

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Stride</td>

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<td align="center" bordercolor="#C0C0C0" bgcolor="#FFFFFF"><<a href="https://www.lynxmotion.com/images/video/bp6srv08.mpg">Video</a>></td>

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<td align="center" bordercolor="#C0C0C0" bgcolor="#FFFFFF"><<a href="https://www.lynxmotion.com/images/video/bp6srv09.mpg">Video</a>></td>

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<td align="center" bordercolor="#C0C0C0" bgcolor="#FFFFFF"><<a href="https://www.lynxmotion.com/images/video/bp6srv02.mpg">Video</a>></td>

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Table 17

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</center>

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II. Creating a Walking

Sequence

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<td valign="top" align="left">Step

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1.

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Run the Sequencer program.

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Select the "empty" project from

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the Project drop down menu, and click on the black "+" to make a

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new project. Enter a name for your project. As we are making the robot

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walk, a name such as "BRAT-Walk" might be applicable.</td>

Figure 1.</td>

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<td valign="top" align="left">Step

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2.

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Now we're faced with an empty project and a screen full of servo blocks.

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To make the screen more manageable, click on "Swap" at the top.

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This will swap the selected servos with the unselected ones. Since no

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servos are unselected, this will clear the screen.

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Now just click on the servos that you

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need, which should be servos 0, 1, 2, 16, 17, and 18.</td>

Figure 2.</td>

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<td valign="top" align="left">Step

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3.

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You can click and drag the servo boxes to arrange them so they resemble

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the robot's physical layout.</td>

Figure 3.</td>

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<td valign="top" align="left">Step

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4.

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You can also name the servos by clicking on the number in the servo box.

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It will bring up the screen in Figure 4. In addition to naming the servo,

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you can change the color of the servo box.</td>

Figure 4.</td>

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<td valign="top" align="left">Step

523

5.

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Now we're almost ready to make the robot walk. First, here's an outline of

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the walking sequence. The last two steps are just mirror images of the

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first two steps.</td>

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<td align="center" bordercolor="#808080" bgcolor="#C0C0C0">Step

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1</td>

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<td align="center" bordercolor="#C0C0C0" bgcolor="#FFFFFF">Shift

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weight to robot's right</td>

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<td align="center" bordercolor="#808080" bgcolor="#C0C0C0">Step

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2</td>

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<td align="center" bordercolor="#C0C0C0" bgcolor="#FFFFFF">Step

forward</td>

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<td align="center" bordercolor="#808080" bgcolor="#C0C0C0">Step

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3</td>

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<td align="center" bordercolor="#C0C0C0" bgcolor="#FFFFFF">Shift

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weight to robot's left</td>

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<td align="center" bordercolor="#808080" bgcolor="#C0C0C0">Step

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4</td>

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<td align="center" bordercolor="#C0C0C0" bgcolor="#FFFFFF">Step

forward</td>

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Table 5.</td>

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</center></div>

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<td valign="top" align="left">Step

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6.

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To make this project even easier, click on the "A<img border="0" src="https://wiki.lynxmotion.com/info/wiki/lynxmotion/download/servo-erector-set-robots-kits/ses-v1-robots/ses-v1-bipeds/brat-biped-seq-b/WebHome/link.gif" >B"

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button in the lower left corner. This screen allows you to link servos

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together. Click on "Servo 1" on the left side and "Servo

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17" on the right, then click "Add." Do the same with Servos

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2 and 18. This will allow you to switch the positions of the right and

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left legs with just a few clicks.</td>

Figure 6.</td>

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<td valign="top" align="left">Step

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7.

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The first step in this walk is to get the robot into position to take a

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stride in the second step. Set your servos to the degrees shown in Table

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7. They don't have to be exact; close will do. When you're done, click on

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the red "=" in the Step section to overwrite Step 1.

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Table 7.</td>

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</center></div>

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Figure 7.</td>

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<td valign="top" align="left">Step

642

8.

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Now, click on "A<=>B" and deselect the "Selected

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step" check box and click OK. Then click the green "+" in

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the Step section to add the current position as a new step.</td>

Figure 8.</td>

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<td valign="top" align="left">Step

654

9.

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To shift the robot's weight, just use the sliders and switch the degrees

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for Servos 0 and 16. Click on the green "+" in the Step section

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when you're done to add this as a new step.</td>

Figure 9.</td>

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</td>

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<td valign="top" align="left">Step

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10.

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Now all you have to do is take another step! Click on the

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"A<=>B" button again, deselect "Selected step"

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if it isn't already, and click OK. Click on the green "+" in the

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Step section when you're done.</td>

Figure 10.</td>

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<td valign="top" align="left">Step

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11.

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To test the walk sequence, click on the sequence loop button on the right

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side of the screen under "Play." You can stop or pause the

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walking sequence from the Play menu.

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If you were successful, the robot should

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be walking now. If the robot doesn't walk in a straight line, try

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increasing the ankle degrees so that more weight is shifted.

</td>

Figure 11.</td>

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<td valign="top" align="left">Step

697

12.

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To adjust the biped's walking speed, you can use the "Advanced

699

Play" feature. Click on the Advanced Play button on the right side of

the screen.</td>

Figure 12.</td>

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<td valign="top" align="left">Step

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13.

712

By moving the Time slider, you will adjust the speed of all the servos in

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the project to a percentage of the normal speed. 100% is the project's

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normal speed. Moving the slider below 100% causes the robot to move

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faster, while above 100% slows the robot down.

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Click on the Loop button to test your new

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speed. You can tweak the speed while the robot is moving to get it

718

perfect.

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If you click on the Apply button, the new

720

speed will be applied to the project. </td>

Figure 13.</td>

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