Move the documentation dection to the top of the page

index.html

@@ -14,6 +14,179 @@
         <p>Interactive simulation of a swerve drive robot with configurable size, speeds, and number of wheels</p>
     </header>
     <main>
+        <section class="documentation">
+            <h2>About This Project</h2>
+            <details>
+                <summary>How To Use</summary>
+                <div class="documentation-content">
+                    <h3>Getting Started</h3>
+                    <p>This interactive visualizer demonstrates how a swerve drive robot moves based on commanded
+                        velocities. Use the controls to experiment with different configurations and movement patterns.
+                    </p>
+
+                    <h3>Drive Controls</h3>
+                    <ul>
+                        <li><strong>Strafe Left/Right:</strong> Controls the robot's velocity in the X direction
+                            (field-relative). Positive values move right, negative values move left.</li>
+                        <li><strong>Move Forward/Backward:</strong> Controls the robot's velocity in the Y direction
+                            (field-relative). Positive values move forward, negative values move backward.</li>
+                        <li><strong>Rotation:</strong> Controls the robot's angular velocity (turn rate) in radians per
+                            second. Positive values rotate counter-clockwise.</li>
+                        <li><strong>Max Module Speed:</strong> Sets the maximum speed limit for any individual swerve
+                            module. If calculated speeds exceed this, all modules are scaled proportionally.</li>
+                        <li><strong>Reset Controls:</strong> Returns all velocity sliders to zero.</li>
+                    </ul>
+
+                    <h3>Preset Configurations</h3>
+                    <p>Choose from 9 pre-built robot configurations ranging from 2 to 16 wheels. Each preset
+                        demonstrates different module arrangements:</p>
+                    <ul>
+                        <li><strong>2-Wheel:</strong> Differential drive arrangement</li>
+                        <li><strong>3-Wheel Triangle:</strong> Three modules in an equilateral triangle</li>
+                        <li><strong>4-Wheel Square:</strong> Classic square configuration</li>
+                        <li><strong>4-Wheel Rectangle:</strong> Rectangular configuration for longer robots</li>
+                        <li><strong>6-Wheel Hexagon:</strong> Hexagonal arrangement</li>
+                        <li><strong>8-Wheel Octagon:</strong> Octagonal arrangement</li>
+                        <li><strong>8-Wheel Square:</strong> Double-layered square with inner and outer modules</li>
+                        <li><strong>12-Wheel Hexagon:</strong> Double-layered hexagonal arrangement</li>
+                        <li><strong>16-Wheel Octagon:</strong> Double-layered octagonal arrangement</li>
+                    </ul>
+
+                    <h3>Custom Configurations</h3>
+                    <p>Create your own robot configuration:</p>
+                    <ol>
+                        <li>Enter the desired number of modules (Minimum of 2)</li>
+                        <li>Click <strong>Generate Position Inputs</strong> to create input fields</li>
+                        <li>For each module, specify:
+                            <ul>
+                                <li><strong>Module Name:</strong> A label for the module</li>
+                                <li><strong>X Position:</strong> Distance from robot center (pixels, positive = right)
+                                </li>
+                                <li><strong>Y Position:</strong> Distance from robot center (pixels, positive = up)</li>
+                            </ul>
+                        </li>
+                        <li>Click <strong>Apply Custom Configuration</strong> to see your design</li>
+                        <li>Use <strong>Remove Position Inputs</strong> to clear the custom fields. This does not reset
+                            the robot, only clears the input box</li>
+                    </ol>
+
+                    <h3>Understanding the Visualization</h3>
+                    <ul>
+                        <li><strong>Robot Frame:</strong> The filled polygon connecting the outer-most module positions
+                        </li>
+                        <li><strong>Modules:</strong> Circular markers at each wheel position</li>
+                        <li><strong>Velocity Arrows:</strong> Red arrows showing the direction and magnitude of each
+                            module's velocity</li>
+                        <li><strong>Grid:</strong> Moves relative to the robot to show field-relative motion</li>
+                        <li><strong>Gyro Heading:</strong> The current rotation angle of the robot in degrees</li>
+                    </ul>
+
+                    <h3>Module States Panel</h3>
+                    <p>Displays real-time information for each module:</p>
+                    <ul>
+                        <li><strong>Angle:</strong> The direction the module is pointing (in degrees)</li>
+                        <li><strong>Speed:</strong> The velocity of the module (in pixels/second)</li>
+                    </ul>
+                </div>
+            </details>
+            <details>
+                <summary>Explanation of Swerve Kinematics</summary>
+                <div class="documentation-content">
+                    <h3>What is Swerve Drive?</h3>
+                    <p>Swerve drive (also called holonomic drive) is a drivetrain design where each wheel module can
+                        independently rotate and drive in any direction. This allows the robot to move in any direction
+                        while simultaneously rotating, providing exceptional maneuverability.</p>
+
+                    <h3>Kinematic Equations</h3>
+                    <p>The simulator calculates each module's state using inverse kinematics. Given a desired robot
+                        velocity (v<sub>x</sub>, v<sub>y</sub>) and rotation rate (ω), we calculate each module's
+                        required velocity.</p>
+
+                    <h4>Field-Relative vs Robot-Relative</h4>
+                    <p>This simulator uses <strong>field-relative control</strong>, meaning the velocity commands are
+                        relative to the field, not the robot's current orientation. The inputs are transformed to
+                        robot-relative coordinates using the current gyro heading:</p>
+                    <pre>
+v<sub>robot_x</sub> = v<sub>field_x</sub> × cos(-θ) - v<sub>field_y</sub> × sin(-θ)
+v<sub>robot_y</sub> = v<sub>field_x</sub> × sin(-θ) + v<sub>field_y</sub> × cos(-θ)
+                    </pre>
+                    <p>Where θ is the robot's heading angle (gyro reading).</p>
+
+                    <h4>Module Velocity Calculation</h4>
+                    <p>For each module at position (x<sub>i</sub>, y<sub>i</sub>) relative to the robot's center of
+                        rotation:</p>
+                    <ol>
+                        <li><strong>Translation component:</strong> The robot's linear velocity (v<sub>robot_x</sub>,
+                            v<sub>robot_y</sub>)</li>
+                        <li><strong>Rotation component:</strong> Perpendicular to the position vector, with magnitude
+                            proportional to distance from center:
+                            <pre>
+v<sub>rot_x</sub> = -y<sub>i</sub> × ω
+v<sub>rot_y</sub> = x<sub>i</sub> × ω
+                            </pre>
+                        </li>
+                        <li><strong>Combined velocity:</strong> Vector sum of translation and rotation:
+                            <pre>
+v<sub>module_x</sub> = v<sub>robot_x</sub> + v<sub>rot_x</sub>
+v<sub>module_y</sub> = v<sub>robot_y</sub> + v<sub>rot_y</sub>
+                            </pre>
+                        </li>
+                    </ol>
+
+                    <h4>Module Angle and Speed</h4>
+                    <p>From the module's velocity vector, we calculate:</p>
+                    <ul>
+                        <li><strong>Speed:</strong> The magnitude of the velocity vector: √(v<sub>x</sub>² +
+                            v<sub>y</sub>²)</li>
+                        <li><strong>Angle:</strong> The direction of the velocity vector: arctan2(v<sub>y</sub>,
+                            v<sub>x</sub>)</li>
+                    </ul>
+
+                    <h4>Speed Normalization</h4>
+                    <p>If any module's calculated speed exceeds the maximum allowed speed, all module velocities are
+                        scaled proportionally. This preserves the movement direction while respecting hardware limits:
+                    </p>
+                    <pre>
+scale = max_speed / max(calculated_speeds)
+if scale &lt; 1:
+    all_module_speeds × scale
+                    </pre>
+
+                    <h3>Gyro Integration</h3>
+                    <p>The robot's heading (gyro angle) is continuously updated by integrating the rotation rate:</p>
+                    <pre>
+θ<sub>new</sub> = θ<sub>old</sub> + ω × Δt
+                    </pre>
+                    <p>Where Δt is the time step. The heading is normalized to stay within the range [-π, π].</p>
+
+                    <h3>Real-World Applications</h3>
+                    <p>Swerve drive systems are commonly used in:</p>
+                    <ul>
+                        <li><strong>FRC (FIRST Robotics Competition):</strong> For competitive robots requiring precise
+                            positioning</li>
+                        <li><strong>Industrial AGVs:</strong> Automated guided vehicles in warehouses</li>
+                        <li><strong>Research Platforms:</strong> Mobile robots requiring omnidirectional movement</li>
+                    </ul>
+
+                    <h3>Key Advantages</h3>
+                    <ul>
+                        <li>True holonomic motion (can move in any direction without rotating)</li>
+                        <li>Can translate and rotate simultaneously</li>
+                        <li>Excellent maneuverability in constrained spaces</li>
+                        <li>No "drift" or unwanted rotation during translation</li>
+                    </ul>
+
+                    <h3>Implementation Considerations</h3>
+                    <ul>
+                        <li><strong>Mechanical Complexity:</strong> Each module requires two motors (drive and steering)
+                        </li>
+                        <li><strong>Control Complexity:</strong> Requires coordinated control of all modules</li>
+                        <li><strong>Sensor Requirements:</strong> Absolute encoders recommended for module angles</li>
+                        <li><strong>Cost:</strong> More expensive than traditional drivetrains</li>
+                    </ul>
+                </div>
+            </details>
+        </section>
         <section class="visualization-canvas">
             <h2>Robot Visualization</h2>
             <canvas id="swerve-canvas" width="800" height="800"></canvas>
@@ -25,18 +198,18 @@
             <fieldset>
                 <legend>Translation &amp; Rotation</legend>
 
-                <div class="control-group">
-                    <label for="vx-slider">Strafe Left/Right (pixels/s)</label>
-                    <input type="range" id="vx-slider" min="-300" max="300" step="10" value="0">
-                    <output id="vx-value">0</output>
-                </div>
-
                 <div class="control-group">
                     <label for="vy-slider">Move Forward/Backward (pixels/s)</label>
                     <input type="range" id="vy-slider" min="-300" max="300" step="10" value="0">
                     <output id="vy-value">0</output>
                 </div>
 
+                <div class="control-group">
+                    <label for="vx-slider">Strafe Left/Right (pixels/s)</label>
+                    <input type="range" id="vx-slider" min="-300" max="300" step="10" value="0">
+                    <output id="vx-value">0</output>
+                </div>
+
                 <div class="control-group">
                     <label for="omega-slider">Rotation (rad/s)</label>
                     <input type="range" id="omega-slider" min="-3" max="3" step="0.1" value="0">
@@ -51,7 +224,7 @@
 
                 <div class="control-group">
                     <label for="max-speed-slider">Max Module Speed (pixels/s)</label>
-                    <input type="range" id="max-speed-slider" min="1" max="300" step="10" value="150">
+                    <input type="range" id="max-speed-slider" min="200" max="1000" step="10" value="400">
                     <output id="max-speed-value">0</output>
                 </div>
             </fieldset>
@@ -67,6 +240,9 @@
                     <button id="preset-4rect" type="button">4-Wheel Rectangle</button>
                     <button id="preset-6wheel" type="button">6-Wheel Hexagon</button>
                     <button id="preset-8wheel" type="button">8-Wheel Octagon</button>
+                    <button id="preset-8square" type="button">8-Wheel Square</button>
+                    <button id="preset-12hex" type="button">12-Wheel Hexagon</button>
+                    <button id="preset-16oct" type="button">16-Wheel Octogon</button>
                 </div>
             </fieldset>
             <fieldset>
@@ -99,15 +275,7 @@
                 <!-- Dynamically generated module data will appear here -->
             </div>
         </section>
-        <section class="documentation">
-            <h2>About This Project</h2>
-            <details>
-                <summary>How To Use</summary>
-            </details>
-            <details>
-                <summary>Explaination of Swerve Kinematics</summary>
-            </details>
-        </section>
+
     </main>
 
     <script type="module" src="vendor/lucio/graham-scan.mjs"></script>

script.js

@@ -86,18 +86,19 @@ class SwerveDrive {
     }
 
     drive(velocityX, velocityY, turnSpeed, maxModuleSpeed, deltaTime = 0.01) {
-        // Update gyro heading first
-        this.updateHeading(turnSpeed, deltaTime);
+        // Store the requested turn speed for later calculation of actual turn speed
+        this.requestedTurnSpeed = turnSpeed;
 
-        // Take in a requested speeds and update every module
+        // Take in a requested speeds and update every module (but don't update heading yet)
         this.modules.forEach(module =>
             module.calculateState(velocityX, velocityY, turnSpeed, this.gyroHeading)
         );
 
         // If any speeds exceed the max speed, normalize down so we don't effect movement direction
         const maxCalculated = Math.max(...this.modules.map(m => m.speed), 0);
+        let scale = 1.0;
         if (maxCalculated > maxModuleSpeed) {
-            const scale = maxModuleSpeed / maxCalculated;
+            scale = maxModuleSpeed / maxCalculated;
             this.modules.forEach(module => {
                 module.velocity.x *= scale;
                 module.velocity.y *= scale;
@@ -105,6 +106,38 @@ class SwerveDrive {
                 module.angle = module.velocity.angle();
             });
         }
+
+        // Update heading with the actual turn speed (scaled if modules were limited)
+        const actualTurnSpeed = turnSpeed * scale;
+        this.updateHeading(actualTurnSpeed, deltaTime);
+        this.actualTurnSpeed = actualTurnSpeed;
+    }
+
+    getActualVelocity() {
+        // Calculate the actual robot velocity from the average of module velocities
+        // This returns the velocity in robot-relative coordinates
+        if (this.modules.length === 0) return new Vec2D(0, 0);
+
+        let sumX = 0;
+        let sumY = 0;
+
+        // Average the module velocities (they're in robot frame)
+        this.modules.forEach(module => {
+            sumX += module.velocity.x;
+            sumY += module.velocity.y;
+        });
+
+        const avgX = sumX / this.modules.length;
+        const avgY = sumY / this.modules.length;
+
+        // Transform back to field-relative coordinates
+        const cosHeading = Math.cos(this.gyroHeading);
+        const sinHeading = Math.sin(this.gyroHeading);
+
+        const fieldVelX = avgX * cosHeading - avgY * sinHeading;
+        const fieldVelY = avgX * sinHeading + avgY * cosHeading;
+
+        return new Vec2D(fieldVelX, fieldVelY);
     }
 }
 
@@ -159,7 +192,7 @@ const PresetConfigs = {
         return modules;
     },
 
-    eightWheel: (size) => {
+    eightWheelOctogon: (size) => {
         const radius = size / 2;
         const modules = [];
         for (let i = 0; i < 8; i++) {
@@ -171,7 +204,64 @@ const PresetConfigs = {
             });
         }
         return modules;
+    },
+
+    eightWheelSquare: (size) => {
+        const full = size;
+        const half = size / 2;
+        return [
+            { x: full, y: full, name: "Outer FL" },
+            { x: full, y: -full, name: "Outer FR" },
+            { x: -full, y: full, name: "Outer BL" },
+            { x: -full, y: -full, name: "Outer BR" },
+            { x: half, y: half, name: "Inner FL" },
+            { x: half, y: -half, name: "Inner FR" },
+            { x: -half, y: half, name: "Inner BL" },
+            { x: -half, y: -half, name: "Inner BR" }
+        ];
+    },
+
+    twelveWheelHexagon: (size) => {
+        const outerRadius = size;
+        const innerRadius = size / 2;
+        const modules = [];
+        for (let i = 0; i < 6; i++) {
+            const angle = (Math.PI / 2) + (i * Math.PI / 3);
+            modules.push({
+                x: outerRadius * Math.cos(angle),
+                y: outerRadius * Math.sin(angle),
+                name: `Module ${i + 1}`
+            });
+
+            modules.push({
+                x: innerRadius * Math.cos(angle),
+                y: innerRadius * Math.sin(angle),
+                name: `Module ${i + 7}`
+            });
         }
+        return modules;
+    },
+
+    sixteenWheelOctogon: (size) => {
+        const outerRadius = size;
+        const innerRadius = size / 2;
+        const modules = [];
+        for (let i = 0; i < 8; i++) {
+            const angle = (Math.PI / 2) + (i * Math.PI / 4);
+            modules.push({
+                x: outerRadius * Math.cos(angle),
+                y: outerRadius * Math.sin(angle),
+                name: `Module ${i + 1}`
+            });
+
+            modules.push({
+                x: innerRadius * Math.cos(angle),
+                y: innerRadius * Math.sin(angle),
+                name: `Module ${i + 9}`
+            });
+        }
+        return modules;
+    },
 };
 
 /*
@@ -205,32 +295,19 @@ const preset4WheelBtn = document.getElementById('preset-4wheel');
 const preset4RectBtn = document.getElementById('preset-4rect');
 const preset6WheelBtn = document.getElementById('preset-6wheel');
 const preset8WheelBtn = document.getElementById('preset-8wheel');
+const preset8SquareBtn = document.getElementById('preset-8square');
+const preset12HexBtn = document.getElementById('preset-12hex');
+const preset16OctBtn = document.getElementById('preset-16oct');
 
 /*
 * END DOM VARIABLES
 * BEGIN LISTENER CODE
 */
 
-
-vxSlider.addEventListener('input', (e) => {
-    vxOutput.textContent = parseFloat(e.target.value);
-});
-vxOutput.textContent = parseFloat(vxSlider.value);
-
-vySlider.addEventListener('input', (e) => {
-    vyOutput.textContent = parseFloat(e.target.value);
-});
-vyOutput.textContent = parseFloat(vySlider.value);
-
-omegaSlider.addEventListener('input', (e) => {
-    omegaOutput.textContent = parseFloat(e.target.value);
-});
-omegaOutput.textContent = parseFloat(omegaSlider.value);
-
 maxSpeedSlider.addEventListener('input', (e) => {
-    maxSpeedOutput.textContent = parseFloat(e.target.value);
+    maxSpeedOutput.textContent = e.target.value;
 });
-maxSpeedOutput.textContent = parseFloat(maxSpeedSlider.value);
+maxSpeedOutput.textContent = maxSpeedSlider.value;
 
 resetBtn.addEventListener('click', (e) => {
     vxSlider.value = 0;
@@ -284,13 +361,39 @@ preset6WheelBtn.addEventListener('click', () => {
 });
 
 preset8WheelBtn.addEventListener('click', () => {
-    const positions = PresetConfigs.eightWheel(robotSize);
+    const positions = PresetConfigs.eightWheelOctogon(robotSize);
     robot.setModules(positions);
     robot.setName("8-Wheel Octogon");
     createModuleDisplays(robot);
     updateModuleDisplays(robot);
 });
 
+preset8SquareBtn.addEventListener('click', () => {
+    const positions = PresetConfigs.eightWheelSquare(robotSize);
+    robot.setModules(positions);
+    robot.setName("8-Wheel Square");
+    createModuleDisplays(robot);
+    updateModuleDisplays(robot);
+});
+
+preset12HexBtn.addEventListener('click', () => {
+    const positions = PresetConfigs.twelveWheelHexagon(robotSize);
+    robot.setModules(positions);
+    robot.setName("12-Wheel Hexagon");
+    createModuleDisplays(robot);
+    updateModuleDisplays(robot);
+});
+
+preset16OctBtn.addEventListener('click', () => {
+    const positions = PresetConfigs.sixteenWheelOctogon(robotSize);
+    robot.setModules(positions);
+    robot.setName("16-Wheel Octogon");
+    createModuleDisplays(robot);
+    updateModuleDisplays(robot);
+});
+
+
+
 generateInputsBtn.addEventListener('click', () => {
     const count = parseInt(moduleCountInput.value);
 
@@ -554,18 +657,27 @@ function animate() {
     ySpeed = -parseFloat(vySlider.value);
     turnSpeed = parseFloat(omegaSlider.value);
 
-    // Animate the grid with robot movement
-    let offsetSpeedDivisor = (100 - gridSquareSize <= 0 ? 1 : 100 - gridSquareSize);
-
-    // Update grid offsets based on robot movement
-    xGridOffset = (xGridOffset + (xSpeed / offsetSpeedDivisor)) % gridSquareSize;
-    yGridOffset = (yGridOffset + (ySpeed / offsetSpeedDivisor)) % gridSquareSize;
-
     // Update module states before drawing the robot
     // The drive() method will update the gyroHeading internally
     robot.drive(xSpeed, ySpeed, turnSpeed, parseFloat(maxSpeedSlider.value));
     updateModuleDisplays(robot);
 
+    // Get the actual robot velocity (after scaling to max module speed) for grid animation
+    const actualVelocity = robot.getActualVelocity();
+
+
+    // Update control outputs with actual speeds
+    vxOutput.textContent = `Requested: ${vxSlider.value} | Actual: ${actualVelocity.x.toFixed(2)}`;
+    vyOutput.textContent = `Requested: ${vySlider.value} | Actual: ${-actualVelocity.y.toFixed(2)}`;
+    omegaOutput.textContent = `Requested: ${omegaSlider.value} | Actual: ${robot.actualTurnSpeed.toFixed(2)}`;
+
+    // Animate the grid
+    let offsetSpeedDivisor = (100 - gridSquareSize <= 0 ? 1 : 100 - gridSquareSize);
+
+    // Update grid offsets based on robot movement
+    xGridOffset = (xGridOffset + (actualVelocity.x / offsetSpeedDivisor)) % gridSquareSize;
+    yGridOffset = (yGridOffset + (actualVelocity.y / offsetSpeedDivisor)) % gridSquareSize;
+
     // Draw the robot and it's movement. Grid should be oversized so movement
     // doesn't find the edge of the grid
     drawGrid(ctx, canvas.width * 2, gridSquareSize, xGridOffset, yGridOffset);

styles.css

@@ -238,7 +238,7 @@ tr:hover {
 
 .visualization-area {
   grid-column: 1 / 2;
-  grid-row: 1 / 3;
+  grid-row: 2 / 4;
 }
 
 #swerve-canvas {
@@ -252,22 +252,22 @@ tr:hover {
 
 .controls-panel {
   grid-column: 1 / 2;
-  grid-row: 2 / 3;
+  grid-row: 3 / 4;
 }
 
 .config-panel {
   grid-column: 2 / 3;
-  grid-row: 1 / 2;
+  grid-row: 2 / 3;
 }
 
 .module-states {
   grid-column: 2 / 3;
-  grid-row: 2 / 3;
+  grid-row: 3 / 4;
 }
 
 .documentation {
   grid-column: 1 / 3;
-  grid-row: 4 / 5;
+  grid-row: 1 / 2;
 }
 
 fieldset {