Real-Time Mode Common Issues

Sub-documents

1. Errors and abnormal behavior
2. Network communication
3. Torque control
4. AR models
5. Other usage and real-time topics

1 Usage notes

1.1 Command planning requirements

User motion commands should satisfy recommended and necessary conditions. Recommended conditions improve smoothness and performance. Necessary conditions must be met; otherwise the robot stops. If recommended conditions are not met, you may see jitter or motor noise during motion.

1.1.1 Joint-space motion

1. Necessary conditions

Joint-space trajectory is smooth; at minimum, velocity must be continuously differentiable:

$$\begin{aligned}q_{\min} &< q_c < q_{\max} \\-\dot{q}_{\max} &< \dot{q}_c < \dot{q}_{\max} \\-\ddot{q}_{\max} &< \ddot{q}_c < \ddot{q}_{\max} \\-\dddot{q}_{\max} &< \dddot{q}_c < \dddot{q}_{\max}\\\end{aligned}$$

2. Recommended conditions

Torque commands within limits:

$$\begin{aligned}-\tau_{j\text{max}} &< \tau_{jc} < \tau_{j\text{max}} \\-\dot{\tau}_{j\text{max}} &< \dot{\tau}_{jc} < \dot{\tau}_{j\text{max}}\\\end{aligned}$$

At motion start:

$$\begin{aligned}q &= q_c \\\dot{q}_c &= 0 \\\ddot{q}_c &= 0\\\end{aligned}$$

At motion end:

$$\begin{aligned}\dot{q}_{c} &= 0 \\\ddot{q}_{c} &= 0\\\end{aligned}$$

1.2 Cartesian-space motion

1. Necessary conditions

Not at a singularity and inside the workspace:

$$\begin{aligned}-\dot{p}_{\max } & <\dot{p}_{c}<\dot{p}_{\max } \\-\ddot{p}_{\max } & <\ddot{p}_{c}<\ddot{p}_{\max } \\-\dddot{p}_{\max } & <\dddot{p}_{c}<\dddot{p}_{\max }\\\end{aligned}$$

2. Recommended conditions

Torque commands within limits:

$$\begin{aligned}\\-\tau_{j\max} &< \tau_{jc} < \tau_{j\max} \\-\dot{\tau}_{j\max} &< \dot{\tau}_{jc} < \dot{\tau}_{j\max}\end{aligned}$$

At motion start:

$$\begin{aligned}\\T &= T_c \\\dot{p}_c &= 0 \\\ddot{p}_c &= 0\\\end{aligned}$$

At motion end:

$$\begin{aligned}\dot{\mathbf{p}}_{\mathrm{c}} &= 0 \\\ddot{\mathbf{p}}_{\mathrm{c}} &= 0\\\end{aligned}$$

1.1.3 Direct torque control

1. Necessary conditions

Torque commands within limits and continuous:

$$\begin{aligned}-\dot{\tau}_{j \max } & <\dot{\tau}_{j c}<\dot{\tau}_{j \max } \\-\tau_{j \max } & <\tau_{j c}<\tau_{j \max }\\\end{aligned}$$

1.1.4 Motion limits

xMateER3 Pro, xMateER7 Pro, xMateER3, xMateER7 — Cartesian motion limits:

Parameter	Translation	Rotation
Velocity	$1.0 m/s$	$2.5 rad/s$
Acceleration	$10.0 m/s^2$	$10.0 rad/s2$
Jerk	$5000.0 m/s^3$	$5000.0 rad/s^3$

xMateER3 Pro and xMateER7 Pro — joint-space limits:

Parameter	Axis 1	Axis 2	Axis 3	Axis 4	Axis 5	Axis 6	Axis 7	Unit
Upper soft limit	170	120	170	120	170	120	360	°
Lower soft limit	-170	-120	-170	-120	-170	-120	-360	°
Max velocity	2.175	2.175	2.175	2.175	2.610	2.610	2.610	$rad/s$
Max acceleration	15	7.5	10	10	15	15	20	$rad/s^2$
Max jerk	5000	3500	5000	5000	7500	7500	7500	$rad/s^3$

xMate3 and xMate7 — joint-space limits:

Parameter	Axis 1	Axis 2	Axis 3	Axis 4	Axis 5	Axis 6	Unit
Upper soft limit	170	120	120	170	120	360	°
Lower soft limit	-170	-120	-120	-170	-120	-360	°
Max velocity	2.175	2.175	2.175	2.610	2.610	2.610	$rad/s$
Max acceleration	15	7.5	10	15	15	20	$rad/s^2$
Max jerk	5000	3500	5000	7500	7500	7500	$rad/s^3$

xMateER3 Pro and xMateER7 Pro — direct torque control limits:

Parameter	Axis 1	Axis 2	Axis 3	Axis 4	Axis 5	Axis 6	Axis 7	Unit
Max torque	85	85	85	85	36	36	36	$Nm$
Max torque derivative	1500	1500	1500	1500	1000	1000	1000	$Nm/s$

xMate3 and xMate7 — direct torque control limits:

Parameter	Axis 1	Axis 2	Axis 3	Axis 4	Axis 5	Axis 6	Unit
Max torque	85	85	85	36	36	36	$Nm$
Max torque derivative	1500	1500	1500	1000	1000	1000	$Nm/s$

1.2 DH parameters

xMateER3 Pro DH table:

Joint	A(mm)	Alpha(rad)	D(mm)	Theta(rad)
1	0	-pi/2	341.5	0
2	0	pi/2	0	0
3	0	-pi/2	394.0	0
4	0	pi/2	0	0
5	0	-pi/2	366	0
6	0	pi/2	0	0
7	0	0	250.3	0

xMateER7 Pro DH table:

Joint	A(mm)	Alpha(rad)	D(mm)	Theta(rad)
1	0	-pi/2	404.0	0
2	0	pi/2	0	0
3	0	-pi/2	437.5	0
4	0	pi/2	0	0
5	0	-pi/2	412.5	0
6	0	pi/2	0	0
7	0	0	275.5	0

xMate3 DH table:

Joint	A(mm)	Alpha(rad)	D(mm)	Theta(rad)
1	0	-pi/2	341.5	0
2	394	0	0	0
3	0	pi/2	0	0
4	0	-pi/2	366	0
5	0	pi/2	0	0
6	0	0	250.3	0

xMate7 DH table:

Joint	A(mm)	Alpha(rad)	D(mm)	Theta(rad)
1	0	-pi/2	404	0
2	437.5	0	0	0
3	0	pi/2	0	0
4	0	-pi/2	412.5	0
5	0	pi/2	0	0
6	0	0	275.5	0

1.3 RCI client compatibility

If you previously used the RCI client, you can use xCoreSDK directly after upgrading the controller to v1.7 or later.

1.3.1 First-time setup

1. Ensure RobotAssist → Communication → RCI is disabled, or confirm from the robot status in the middle of the status bar.

2. Call setMotionControlMode (RtCommand) to enable RCI. On success the robot enters RCI state and the status bar shows RCI:

3. After that you can toggle RCI via the SDK or RobotAssist. If you perform a factory reset / erase configuration, treat it as first-time setup again and re-enable RCI through the SDK.

1.3.2 Switching back to the RCI client

After using the SDK, the RCI client cannot be used at the same time. To switch back, call useRciClient(true) with RCI off as required by the API documentation, then use RobotAssist to toggle RCI.