Channel Manifests - Bedrock Dynamics

A channel manifest describes a robot’s control and state interface. It defines the named, typed, bounded channels that a WASM controller reads from and writes to on every tick. The safety filter uses these same definitions to clamp values before they reach actuators. Manifests follow the ros2_control / MuJoCo / Drake pattern: each robot exposes N command channels (written by the controller) and M state channels (read by the controller). The WASM controller accesses channels by index. The safety filter enforces per-channel limits.

Built-In Manifests

roz ships with factory methods for common robot types. Each method returns a ChannelManifest with the correct channels, limits, and rates preconfigured.

UR5 Manipulator

ChannelManifest::ur5()

6-DOF arm with velocity control and full joint state feedback. 6 command channels, 12 state channels (6 position + 6 velocity). Command Channels (6)

Index	Name	Type	Unit	Limits	Rate Limit
0	`shoulder_pan_joint/velocity`	Velocity	rad/s	-3.14, 3.14	0.5
1	`shoulder_lift_joint/velocity`	Velocity	rad/s	-3.14, 3.14	0.5
2	`elbow_joint/velocity`	Velocity	rad/s	-3.14, 3.14	0.5
3	`wrist_1_joint/velocity`	Velocity	rad/s	-3.14, 3.14	0.5
4	`wrist_2_joint/velocity`	Velocity	rad/s	-3.14, 3.14	0.5
5	`wrist_3_joint/velocity`	Velocity	rad/s	-3.14, 3.14	0.5

Each command channel is paired with its corresponding position state channel (via position_state_index) for position limit enforcement. State Channels (12)

Index	Name	Type	Unit	Limits
0	`shoulder_pan_joint/position`	Position	rad	-6.28, 6.28
1	`shoulder_lift_joint/position`	Position	rad	-6.28, 6.28
2	`elbow_joint/position`	Position	rad	-6.28, 6.28
3	`wrist_1_joint/position`	Position	rad	-6.28, 6.28
4	`wrist_2_joint/position`	Position	rad	-6.28, 6.28
5	`wrist_3_joint/position`	Position	rad	-6.28, 6.28
6	`shoulder_pan_joint/velocity`	Velocity	rad/s	-3.14, 3.14
7	`shoulder_lift_joint/velocity`	Velocity	rad/s	-3.14, 3.14
8	`elbow_joint/velocity`	Velocity	rad/s	-3.14, 3.14
9	`wrist_1_joint/velocity`	Velocity	rad/s	-3.14, 3.14
10	`wrist_2_joint/velocity`	Velocity	rad/s	-3.14, 3.14
11	`wrist_3_joint/velocity`	Velocity	rad/s	-3.14, 3.14

Quadcopter

ChannelManifest::quadcopter()

Body-frame velocity control for drones. 4 command channels, 4 state channels. Command Channels (4)

Index	Name	Type	Unit	Limits	Rate Limit
0	`body/velocity.x`	Velocity	m/s	-5.0, 5.0	2.0
1	`body/velocity.y`	Velocity	m/s	-5.0, 5.0	2.0
2	`body/velocity.z`	Velocity	m/s	-3.0, 3.0	1.5
3	`body/yaw_rate`	Velocity	rad/s	-1.57, 1.57	1.0

State Channels (4)

Index	Name	Type	Unit	Limits
0	`body/position.x`	Position	m	-1000.0, 1000.0
1	`body/position.y`	Position	m	-1000.0, 1000.0
2	`body/position.z`	Position	m	0.0, 500.0
3	`body/yaw`	Position	rad	-3.14, 3.14

Differential Drive

ChannelManifest::diff_drive()

Twist-based control for wheeled mobile robots. 2 command channels, 3 state channels. Command Channels (2)

Index	Name	Type	Unit	Limits	Rate Limit
0	`base/linear.x`	Velocity	m/s	-1.0, 1.0	0.5
1	`base/angular.z`	Velocity	rad/s	-2.0, 2.0	1.0

State Channels (3)

Index	Name	Type	Unit	Limits
0	`base/odom.x`	Position	m	-1000.0, 1000.0
1	`base/odom.y`	Position	m	-1000.0, 1000.0
2	`base/odom.yaw`	Position	rad	-3.14, 3.14

Generic Velocity

ChannelManifest::generic_velocity(n_joints, max_velocity)

Creates n_joints velocity command channels with symmetric limits (-max_velocity, max_velocity) and no state channels. Useful for quick prototyping or when you know the joint count and velocity limit but not the full robot specification.

// 4-joint arm with 2.0 rad/s limit
let manifest = ChannelManifest::generic_velocity(4, 2.0);
// Creates: joint0/velocity, joint1/velocity, joint2/velocity, joint3/velocity

Channel Descriptor Fields

Each channel is described by a ChannelDescriptor with these fields:

Field	Type	Description
`name`	String	Channel name following `ros2_control` convention: `"joint_name/interface_type"`
`interface_type`	InterfaceType	`Position`, `Velocity`, or `Effort`
`unit`	String	Physical unit: `"rad"`, `"rad/s"`, `"m"`, `"m/s"`, `"Nm"`, `"N"`
`limits`	(f64, f64)	`(min, max)` value limits enforced by the safety filter
`default`	f64	Safe default value, usually `0.0`
`max_rate_of_change`	Option<f64>	Max change per tick for acceleration limiting. `None` = no rate limiting.
`position_state_index`	Option<usize>	Index of the corresponding position state channel for position limit checks.

Custom Manifests

You can define custom manifests by constructing a ChannelManifest directly:

use roz_core::channels::{ChannelManifest, ChannelDescriptor, InterfaceType};

let manifest = ChannelManifest {
    robot_id: "my_robot".into(),
    robot_class: "manipulator".into(),
    control_rate_hz: 100,
    commands: vec![
        ChannelDescriptor {
            name: "joint0/velocity".into(),
            interface_type: InterfaceType::Velocity,
            unit: "rad/s".into(),
            limits: (-2.0, 2.0),
            default: 0.0,
            max_rate_of_change: Some(0.3),
            position_state_index: Some(0),
        },
    ],
    states: vec![
        ChannelDescriptor {
            name: "joint0/position".into(),
            interface_type: InterfaceType::Position,
            unit: "rad".into(),
            limits: (-6.28, 6.28),
            default: 0.0,
            max_rate_of_change: None,
            position_state_index: None,
        },
    ],
};

robot.toml

When using roz sim start, the sim container provides its channel manifest automatically. For custom robots, you can define the manifest in a robot.toml file:

[manifest]
robot_id = "my_robot"
robot_class = "manipulator"
control_rate_hz = 100

[[manifest.commands]]
name = "joint0/velocity"
interface_type = "velocity"
unit = "rad/s"
limits = [-2.0, 2.0]
default = 0.0
max_rate_of_change = 0.3
position_state_index = 0

[[manifest.states]]
name = "joint0/position"
interface_type = "position"
unit = "rad"
limits = [-6.28, 6.28]
default = 0.0

Source Code

Channel manifest definitions: crates/roz-core/src/channels.rs

​Built-In Manifests

​UR5 Manipulator

​Quadcopter

​Differential Drive

​Generic Velocity

​Channel Descriptor Fields

​Custom Manifests

​robot.toml

​Source Code