15.Isaac教程--Isaac机器人引擎简介
Isaac机器人引擎简介
ISAAC教程合集地址: https://blog.csdn.net/kunhe0512/category_12163211.html
文章目录
- Isaac机器人引擎简介
-
- 基础
- Codelets
- 完整的应用
基础
本节介绍如何使用 Isaac 机器人引擎。 它介绍了相关术语并解释了 Isaac 应用程序的结构。
Isaac 应用程序由 JavaScript Object Notation (JSON) 文件定义。 以下示例位于 /sdk/apps/tutorials/ping/ping.app.json 的 Isaac SDK 中，显示了基本格式。
{
"name": "ping",
"modules": [
"//apps/tutorials/ping:ping_components",
"sight"
],
"graph": {
"nodes": [
{
"name": "ping",
"components": [
{
"name": "ping",
"type": "isaac::Ping"
}
]
}
],
"edges": []
},
"config": {
"ping" : {
"ping" : {
"message": "My own hello world!",
"tick_period" : "1Hz"
}
}
}
}
Isaac 应用程序由四个部分定义：
-
name是一个包含应用程序名称的字符串。 -
modules是正在使用的库列表。 在上面的示例中，我们包含//apps/tutorials/ping:ping_components以便“apps/tutorials/ping/Ping.cpp”可用。 Isaac SDK 带有高质量和经过良好测试的包，可以作为模块导入。 本教程后面将显示一个更长的模块示例。 -
graph有两个小节来定义应用程序的功能：-
nodes是我们应用程序的基本构建块。 在这个简单的例子中，我们只有一个名为“ping”的节点，它只有一个组件。 请注意，此组件的类型isaac::Ping与apps/tutorials/ping/Ping.hpp的最后一行匹配。 一个典型的 Isaac 应用程序有多个节点，每个节点通常有多个组件。 -
edges将组件连接在一起并使它们之间能够通信。 此示例不需要连接任何组件。
-
-
config允许您根据您的用例调整每个节点的参数。 在此示例中，指定“ping”分量应以 1 赫兹tick。
定义应用程序后，接下来您需要创建一个 makefile。 以下是与 ping 应用程序关联的 BUILD 文件。
load("//bzl:module.bzl", "isaac_app", "isaac_cc_module")
isaac_cc_module(
name = "ping_components",
srcs = ["Ping.cpp"],
hdrs = ["Ping.hpp"],
)
isaac_app(
name = "ping",
data = ["fast_ping.json"],
modules = [
"sight",
"//apps/tutorials/ping:ping_components",
],
)
Codelets
Codelets 是使用 Isaac 构建的机器人应用程序的基本构建块。 Isaac SDK 包括您可以在您的应用程序中使用的各种小代码。 下面的示例说明了如何导出Codelets。
为了更好地理解Codelets，请参阅了解Codelets部分。
以下 Ping.hpp 和 Ping.cpp 清单显示了位于 sdk/apps/tutorials/ping 的示例Codelets的源代码：
// This is the header file located at sdk/apps/tutorials/ping/Ping.hpp
#pragma once
#include // This is the C++ file located at apps/tutorials/ping/Ping.cpp
#include "Ping.hpp"
namespace isaac {
void Ping::start() {
// This part will be run once in the beginning of the program
// We can tick periodically, on every message, or blocking. The tick period is set in the
// json ping.app.json file. You can for example change the value there to change the tick
// frequency of the node.
// Alternatively you can also overwrite configuration with an existing configuration file like
// in the example file fast_ping.json. Run the application like this to use an additional config
// file:
// bazel run //apps/tutorials/ping -- --config apps/tutorials/ping/fast_ping.json
tickPeriodically();
}
void Ping::tick() {
// This part will be run at every tick. We are ticking periodically in this example.
// Print the desired message to the console
LOG_INFO(get_message().c_str());
}
} // namespace isaac
完整的应用
下面显示的应用程序（位于 /sdk/apps/tutorials/proportional_control_cpp）功能更强大，具有具有多个节点的图、具有多个组件的节点、节点之间的边以及接收和传输消息的Codelets。
首先查看 JSON 文件以了解边缘是如何定义的。 请注意，此文件比上面的 ping 示例更长，但它遵循完全相同的语法。
{
"name": "proportional_control_cpp",
"modules": [
"//apps/tutorials/proportional_control_cpp:proportional_control_cpp_codelet",
"navigation",
"segway",
"sight"
],
"config": {
"cpp_controller": {
"isaac.ProportionalControlCpp": {
"tick_period": "10ms"
}
},
"segway_rmp": {
"isaac.SegwayRmpDriver": {
"ip": "192.168.0.40",
"tick_period": "20ms",
"speed_limit_angular": 1.0,
"speed_limit_linear": 1.0,
"flip_orientation": true
},
"isaac.alice.Failsafe": {
"name": "robot_failsafe"
}
},
"odometry": {
"isaac.navigation.DifferentialBaseOdometry": {
"tick_period": "100Hz"
}
},
"websight": {
"WebsightServer": {
"port": 3000,
"ui_config": {
"windows": {
"Proportional Control C++": {
"renderer": "plot",
"channels": [
{ "name": "proportional_control_cpp/cpp_controller/isaac.ProportionalControlCpp/reference (m)" },
{ "name": "proportional_control_cpp/cpp_controller/isaac.ProportionalControlCpp/position (m)" }
]
}
}
}
}
}
},
"graph": {
"nodes": [
{
"name": "cpp_controller",
"components": [
{
"name": "message_ledger",
"type": "isaac::alice::MessageLedger"
},
{
"name": "isaac.ProportionalControlCpp",
"type": "isaac::ProportionalControlCpp"
}
]
},
{
"name": "segway_rmp",
"components": [
{
"name": "message_ledger",
"type": "isaac::alice::MessageLedger"
},
{
"name": "isaac.SegwayRmpDriver",
"type": "isaac::SegwayRmpDriver"
},
{
"name": "isaac.alice.Failsafe",
"type": "isaac::alice::Failsafe"
}
]
},
{
"name": "odometry",
"components": [
{
"name": "message_ledger",
"type": "isaac::alice::MessageLedger"
},
{
"name": "isaac.navigation.DifferentialBaseOdometry",
"type": "isaac::navigation::DifferentialBaseOdometry"
}
]
},
{
"name": "commander",
"subgraph": "packages/navigation/apps/differential_base_commander.subgraph.json"
}
],
"edges": [
{
"source": "segway_rmp/isaac.SegwayRmpDriver/segway_state",
"target": "odometry/isaac.navigation.DifferentialBaseOdometry/state"
},
{
"source": "odometry/isaac.navigation.DifferentialBaseOdometry/odometry",
"target": "cpp_controller/isaac.ProportionalControlCpp/odometry"
},
{
"source": "cpp_controller/isaac.ProportionalControlCpp/cmd",
"target": "commander.subgraph/interface/control"
},
{
"source": "commander.subgraph/interface/command",
"target": "segway_rmp/isaac.SegwayRmpDriver/segway_cmd"
}
]
}
}
文件 isaac_app 与 ping 示例非常相似。 但是，添加了此应用程序所需的模块，如“segway”。
load("//bzl:module.bzl", "isaac_app", "isaac_cc_module")
isaac_cc_module(
name = "proportional_control_cpp_codelet",
srcs = ["ProportionalControlCpp.cpp"],
hdrs = ["ProportionalControlCpp.hpp"],
visibility = ["//visibility:public"],
deps = [
"//messages/state:differential_base",
"//packages/engine_gems/state:io",
],
)
isaac_app(
name = "proportional_control_cpp",
data = [
"//packages/navigation/apps:differential_base_commander_subgraph",
],
modules = [
"//apps/tutorials/proportional_control_cpp:proportional_control_cpp_codelet",
"navigation",
"segway",
"sensors:joystick",
"sight",
"viewers",
],
)
下面的 ProportionalControlCpp 小码可以通过 ISAAC_PROTO_RX 和 ISAAC_PROTO_TX 宏以及 JSON 文件中的关联边与其他组件进行通信。
// This is the header file located at
// sdk/apps/tutorials/proportional_control_cpp/ProportionalControlCpp.hpp
#pragma once
#include "engine/alice/alice_codelet.hpp"
#include "messages/differential_base.capnp.h"
#include "messages/state.capnp.h"
namespace isaac {
// A C++ codelet for proportional control
//
// We receive odometry information, from which we extract the x position. Then, using refence and
// gain parameters that are provided by the user, we compute and publish a linear speed command
// using `control = gain * (reference - position)`
class ProportionalControlCpp : public alice::Codelet {
public:
// Has whatever needs to be run in the beginning of the program
void start() override;
// Has whatever needs to be run repeatedly
void tick() override;
// List of messages this codelet recevies
ISAAC_PROTO_RX(Odometry2Proto, odometry);
// List of messages this codelet transmits
ISAAC_PROTO_TX(StateProto, cmd);
// Gain for the proportional controller
ISAAC_PARAM(double, gain, 1.0);
// Reference for the controller
ISAAC_PARAM(double, desired_position_meters, 1.0);
};
} // namespace isaac
ISAAC_ALICE_REGISTER_CODELET(isaac::ProportionalControlCpp);
// This is the C++ file located at
// apps/tutorials/proportional_control_cpp/ProportionalControlCpp.cpp
#include "ProportionalControlCpp.hpp"
#include "messages/math.hpp"
#include "messages/state/differential_base.hpp"
#include "packages/engine_gems/state/io.hpp"
namespace isaac {
void ProportionalControlCpp::start() {
// This part will be run once in the beginning of the program
// Print some information
LOG_INFO("Please head to the Sight website at : to see how I am doing." );
LOG_INFO(" is the Internet Protocol address where the app is running," );
LOG_INFO("and is set in the config file, typically to '3000'." );
LOG_INFO("By default, local link is 'localhost:3000'.");
// We can tick periodically, on every message, or blocking. See documentation for details.
tickPeriodically();
}
void ProportionalControlCpp::tick() {
// This part will be run at every tick. We are ticking periodically in this example.
// Nothing to do if we haven't received odometry data yet
if (!rx_odometry().available()) {
return;
}
// Read parameters that can be set through Sight webpage
const double reference = get_desired_position_meters();
const double gain = get_gain();
// Read odometry message received
const auto& odom_reader = rx_odometry().getProto();
const Pose2d odometry_T_robot = FromProto(odom_reader.getOdomTRobot());
const double position = odometry_T_robot.translation.x();
// Compute the control action
const double control = gain * (reference - position);
// Show some data in Sight
show("reference (m)", reference);
show("position (m)", position);
show("control", control);
show("gain", gain);
// Publish control command
messages::DifferentialBaseControl command;
command.linear_speed() = control;
command.angular_speed() = 0.0; // This simple example sets zero angular speed
ToProto(command, tx_cmd().initProto(), tx_cmd().buffers());
tx_cmd().publish();
}
} // namespace isaac