Core Interfaces and Data Types

Command Sending Interface

The Sender class is responsible for sending joint control commands and mode switching commands to the robot via UDP.

Construction Example

Sender* send_cmd = new Sender("192.168.1.120", 43893);  ///< Specify robot IP and port

Main Interfaces

void SendCmd(RobotCmd& robot_cmd);     ///< Send 12-joint control command
void ControlGet(uint32_t mode);        ///< Control switch: SDK(2) or ROBOT(1)
void RobotStateInit(void);             ///< All joints return to zero and acquire control
void AllJointBackZero(void);           ///< All joints return to zero
void SetCmd(uint32_t code, uint32_t value);  ///< Send raw command code

Control Mode

Mode	Constant	Description
SDK Control	SDK (value 2)	SDK has control authority, can send joint commands
Robot Control	ROBOT (value 1)	Return control authority to the low-level controller

Data Receiving Interface

The Receiver class is responsible for receiving status data reported by the robot via UDP.

Construction and Start Example

Receiver* robot_data_recv = new Receiver();       ///< Create receiver
robot_data_recv->StartWork();                      ///< Start receiving thread
RobotData& data = robot_data_recv->GetState();     ///< Get latest state reference

Callback Registration Example

void OnMessageUpdate(uint32_t code) {
    if (code == 0x0906) {
        is_message_updated_ = true;  ///< Mark that robot data has been received
    }
}

robot_data_recv->RegisterCallBack(OnMessageUpdate);

The callback function is invoked each time a robot data update is received. The parameter code value of 0x0906 indicates a joint data update event.

Safe Sending Protection

It is recommended to confirm receipt of robot data before sending control commands:

if (is_message_updated_) {
    send_cmd->SendCmd(robot_joint_cmd);
}

High-Precision Timer Interface

DRTimer implements millisecond-level precision timing control based on Linux timerfd + epoll.

Interface Example

DRTimer set_timer;
set_timer.TimeInit(1);                                  ///< Initialize, period 1ms
double start_time = set_timer.GetCurrentTime();          ///< Get current time
if (set_timer.TimerInterrupt() == true) { continue; }   ///< Wait for timer interrupt
double now_time = set_timer.GetIntervalTime(start_time); ///< Get elapsed time (seconds)

Data Type Definitions

All data types are defined in robot_types.h.

Joint State Data (JointData)

typedef struct {
    float position;    ///< Joint position (unit: rad)
    float velocity;    ///< Joint velocity (unit: rad/s)
    float torque;      ///< Joint torque (unit: Nm)
    float temperature; ///< Motor temperature (unit: °C)
} JointData;

Joint Control Command (JointCmd)

typedef struct {
    float position; ///< Target position (unit: rad)
    float velocity; ///< Target velocity (unit: rad/s)
    float torque;   ///< Feedforward torque (unit: Nm)
    float kp;       ///< Position stiffness gain
    float kd;       ///< Velocity damping gain
} JointCmd;

IMU Data (ImuData)

struct ImuData {
    int32_t timestamp;            ///< Timestamp (ms)
    float angle_roll;             ///< Roll angle (°)
    float angle_pitch;            ///< Pitch angle (°)
    float angle_yaw;              ///< Yaw angle (°)
    float angular_velocity_roll;  ///< Roll angular velocity (°/s)
    float angular_velocity_pitch; ///< Pitch angular velocity (°/s)
    float angular_velocity_yaw;   ///< Yaw angular velocity (°/s)
    float acc_x;                  ///< X-axis acceleration (m/s²)
    float acc_y;                  ///< Y-axis acceleration (m/s²)
    float acc_z;                  ///< Z-axis acceleration (m/s²)
};

Robot Comprehensive Data (RobotData)

typedef struct {
    uint32_t tick;              ///< Running period count
    ImuData imu;                ///< IMU data
    LegData joint_data;         ///< 12-joint state data
    ContactForce contact_force; ///< Quadruped contact force data
} RobotData;

Joint Ordering

The unified ordering of all 12 joints is:

Index	Joint Name	Leg
0	FL_HipX	Front Left
1	FL_HipY	Front Left
2	FL_Knee	Front Left
3	FR_HipX	Front Right
4	FR_HipY	Front Right
5	FR_Knee	Front Right
6	HL_HipX	Rear Left
7	HL_HipY	Rear Left
8	HL_Knee	Rear Left
9	HR_HipX	Rear Right
10	HR_HipY	Rear Right
11	HR_Knee	Rear Right

Joints can also be accessed via leg structures:

robot_data->joint_data.fl_leg[3]  ///< Front left leg 3 joints
robot_data->joint_data.fr_leg[3]  ///< Front right leg 3 joints
robot_data->joint_data.hl_leg[3]  ///< Rear left leg 3 joints
robot_data->joint_data.hr_leg[3]  ///< Rear right leg 3 joints

Contact Force Data

robot_data->contact_force.fl_leg[]  ///< Front left foot tip X/Y/Z tri-axial contact force
robot_data->contact_force.fr_leg[]  ///< Front right foot tip X/Y/Z tri-axial contact force
robot_data->contact_force.hl_leg[]  ///< Rear left foot tip X/Y/Z tri-axial contact force
robot_data->contact_force.hr_leg[]  ///< Rear right foot tip X/Y/Z tri-axial contact force
robot_data->contact_force.leg_force[] ///< All 12-dimensional contact force

Tip: In most application scenarios, only the Z-direction contact force is used.