Motion Magic
Motion Magic: Profiled Motion Control
Motion Magic builds on PID control by adding smooth acceleration and deceleration profiles. This prevents jerky movements and reduces mechanical stress while maintaining precise positioning.
Motion Magic automatically generates smooth velocity profiles to reach target positions with controlled acceleration.
Understanding Motion Magic Profiles
Trapezoidal Profile
Motion Magic creates a trapezoidal velocity profile with three phases:
Key Parameters
Motion Magic Cruise Velocity
Maximum velocity during cruise phase (rotations/second)
Motion Magic Acceleration
Rate of acceleration/deceleration (rotations/second²)
Motion Magic Jerk
Rate of change of acceleration (rotations/second³)
Official Motion Magic Documentation
For the full Motion Magic reference and configuration examples:
CTRE Motion Magic API ReferenceMotion Magic Tuning Steps
Position Mechanisms (Arms, Elevators)
1. Calculate Maximum Velocity:
- Motor Speed:The Kraken X44 runs about 125 RPS at maximum (CTRE's dyno measures ~129)
- Efficiency: Best used around 80% efficiency
- Gear Ratio: Our 25:1 arm gearing reduces speed
maxVel = (125 / 25) * 0.8 = 4.0 RPS
2. Set Motion Magic Parameters:
- Cruise Velocity: Use calculated max velocity
cruiseVel = 2.0; // conservative start (calculated max is 4.0)- Acceleration: Start with 2x–4x cruise velocity for smooth motion (the workshop example uses 4x)
- Competition: Typically end up with 4x to 10x cruise velocity
acceleration = cruiseVel * 4.0; // = 8.0, matches the example
Velocity Mechanisms (Flywheels, Shooters)
1. Calculate Maximum Velocity:
- Motor Speed:The Kraken X44 runs about 125 RPS at maximum (CTRE's dyno measures ~129)
- Efficiency: Best used around 80% efficiency
- Direct Drive: Using Kraken encoder directly on flywheel
maxVel = 125 * 0.8 = 100 RPS
2. Set Motion Magic Parameters:
- Target Velocity:Use calculated max velocity (for a flywheel, the setpoint IS the target speed; there's no separate cruise phase)
targetVel = 80.0; // comfortably under that ceiling- Acceleration: Start with 2x target velocity for smooth spin-up
- Competition: Typically end up with 4x to 10x cruise velocity
acceleration = cruiseVel * 2.0; // smooth start
Why This Method Works:
Calculating cruise velocity from motor specs and efficiency gives you motion limits the mechanism can actually hit, so the profile stays smooth instead of oscillating. Start with 2x acceleration for smooth motion; competition robots often end up at 4x to 10x cruise velocity for faster response.
Motion Magic Tuning Tutorial
This video walks through Motion Magic tuning and how to pick each parameter:
Motion Magic Implementation in Code
Motion Magic Configuration Example
Workshop Implementation: Motion Magic
Before & After: Implementation
Before
- • PID position control with PositionVoltage
- • Instant acceleration to target
- • Potential mechanical stress from jerky movements
- • No velocity planning or profiling
- • Abrupt start/stop motions
After
- • Motion Magic profiled motion with MotionMagicVoltage
- • Smooth acceleration and deceleration curves
- • Reduced mechanical stress and wear
- • Configurable cruise velocity and acceleration
- • Smooth, predictable motion profiles
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Code Walkthrough
Motion Magic Example Params for 25:1 Arm:
- • 25:1 Gearing: The Kraken X44 runs ~125 RPS, so 5 RPS theoretical max at output
- • Cruise Velocity (2.0): Conservative start: can reach 5 RPS but load may reduce performance
- • Acceleration (8.0): How quickly to reach cruise speed
- • Jerk (80.0): Smoothness of acceleration changes
- • MotionMagicVoltage: Replaces PositionVoltage for profiled control
Enhanced Features:
- • Setpoint Detection: Checks both position AND velocity
- • Smooth Motion: Eliminates jerky arm movements
- • Mechanical Safety: Reduces stress on gearboxes
- • Predictable Timing: Known motion duration
The arm now follows a smooth, profiled path to each target. Next, we cover tuning methods to get the best performance out of these controllers.
Motion Magic vs Basic PID
When to Use Basic PID:
- Simple positioning tasks
- Continuous control (like maintaining angle)
- When speed of response is critical
- Mechanisms with very low inertia
When to Use Motion Magic:
- Large, heavy mechanisms (arms, elevators)
- When smooth motion is important
- Preventing mechanical stress
- Predictable motion timing needed
This is the WPILib 2027 alpha
2027.0.0-alpha-6, Phoenix 6 26.50.0-alpha-1) on Java 25 and SystemCore — so exact APIs may still shift between alpha builds. This page was last verified against alpha-6 in July 2026.