Ontology Parameters:

RM65 Series Parameters and D-H Model

Basic Parameters

Parameter Name		Parameter Value
Basic Parameters	Degrees of Freedom	6
	Configuration	Humanoid Configuration
	Joint Brake Type	Joints 1 to 3: Hard Brake Joints 4 to 6: Soft Brake
	Working Radius/mm	Standard Version: 610 Six-Axis Force L Version: 627 Six-Axis Force K Version: 638.5
	Payload/kg	5
	Self-weight/kg	Standard Version: 7.2 Six-Axis Force Version: 7.3
	Repeatability/mm	±0.05
	TCP Line Speed/m/s	≤1.8
	Typical Power/W	≤150
	Peak Power/W	≤900
	Installation Angle	Any Angle
	Base Dimensions/mm	φ107
	Material	Aluminum Alloy/ABS
Environmental Adaptability	Operating Temperature/℃	0-45
	Operating Humidity	25~85% Non-condensing
Motion Angle Range/°	J1	-178~+178
	J2	-130~+130
	J3	-135~+135
	J4	-178~+178
	J5	-128~+128
	J6	-360~+360
Maximum Angular Velocity/°/s	J1	180
	J2	180
	J3	225
	J4	225
	J5	225
	J6	225
Force Control Specifications (Supported only by 6-DoF sensors)	Six-Axis Force Range	200N/7N·m
	Six-Axis Force Accuracy	±0.5%FS

Ontology Parameters

MDH model frame:

MDH parameters of RM65 (modified D-H parameters):

joint_id(i)	$a_{i-1}$(mm)	${\alpha }_{i-1}$(°)	$d_i$(mm)	${\theta }_i$ / $offse{t}_i$(°)
1	0	0	240.5	0
2	0	90	0	90
3	256	0	0	90
4	0	90	210	0
5	0	-90	0	0
6	0	90	$d_6$	0

• RM65-6FB-V : $d_6=184$ mm
• RM65-B-V     : $d_6=166.8$ mm
• RM65-B         : $d_6=144$ mm
• RM65-6FB     : $d_6=161.2$ mm
• RM65-6F       : $d_6=172.5$ mm

Note: offset refers to the offset of the joint zero position from the model zero position, that is, model angle = joint angle + offset.

Kinetic parameters of RM65 robot link

joint_id(i)	1	2	3	4	5	6	-	-
$m$	1.51	1.653	0.726	0.671	0.647	0.107	0.248	0.189
$x$	0.491	183.722	0.029	0.007	0.032	-0.506	-0.426	-0.352
$y$	7.803	0.103	-90.105	-9.486	-83.769	0.255	0.237	-0.067
$z$	-10.744	-1.665	4.039	-8.041	2.326	-10.801	-27.223	-18.302
$L_{xx}$	2928.466	1711.553	7259.884	794.014	5375.604	50.918	308.844	133.613
$L_{xy}$	-32.63	-38.271	2.994	-0.821	2.665	-3.136	-3.781	0.522
$L_{xz}$	-5.816	2314.91	-0.314	-0.655	-0.304	-0.699	-1.468	1.623
$L_{yy}$	2506.35	70514.722	371.872	596.235	285.265	47.42	304.616	130.260
$L_{yz}$	47.925	6.507	44.451	-34.785	14.235	0.388	0.888	0.531
$L_{zz}$	1756.017	70036.186	7228.758	486.228	5359.769	60.35	122.62	89.503
Remarks						B	6F	6FB

Description:

• $m$ is the mass of the link, $kg$
• $x$ is the x-coordinate of the center of mass of link, $mm$
• $y$ is the y-coordinate of the center of mass of link, $mm$
• $z$ is the z-coordinate of the center of mass of link, $mm$
• $L_{xx}$,$L_{xy}$,$L_{xz}$,$L_{yy}$,$L_{yz}$,$L_{zz}$ is the principal moment of inertia described in the link frame, $kg·mm²$
• B: standard version, 6FB: Six-Axis Force L Version, 6F: six-axis force K version

Remarks:

• Source of data: CAD design values.
• If the inertial parameters in the center of mass frame are required, they can be calculated based on the parallel axis theorem, as stated below.

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Assuming there is an output frame $\{i\}$, the center of mass frame coinciding with this coordinate system $\{i\}$ is $\{c\}$, and the coordinates of the center of mass in this frame $\{i\}$ are $P_c=[x_c,y_c,z_c{]}^T$, then according to the parallel axis theorem:

$$I_c=L_i-m(P_c^T{P}_c{I}_{3\times 3}-P_c{P}_c^T)$$

Where,

$$L_i=\left[\begin{array}{ccc}{L}_{xx}& L_{xy}& L_{xz}\\ L_{xy}& L_{yy}& L_{yz}\\ L_{xz}& L_{yz}& L_{zz}\end{array}\right]$$

Distribution and dimensions of joints

The RM65-B humanoid robotic arm has six rotating joints, each of which represents one degree of freedom. As shown in the figure below, robot joints include the shoulders (joint 1 and joint 2), elbow (joint 3), and wrists (joint 4, joint 5, and joint 6).

Workspace

The workspace of RM65-B is a sphere with a working radius of 610 mm, in addition to the cylindrical space directly above and below the base. When determining the installation position of the robot, due considerations must be given to the cylindrical space directly above and below the robot, to avoid moving tools to this cylindrical space as much as possible. Furthermore, in actual applications, the motion ranges of all joints are as follows: joint 1: ±178°; joint 2: ±130°; joint 3: ±135°; joint 4: ±178°; joint 5: ±128°; joint 6: ±360°.

Seen from the cross-section of the workspace, the area with good maneuverability of the 6-axis robot is as indicated by the yellow dotted line in the following figure, an annular area in the workspace as a whole.

Motion singularities

Singular Type 1: Shoulder singularity

When the intersection point of the axes of Joint 5 and Joint 6 lies on the plane that passes through the axis of Joint 1 and is parallel to the axis of Joint 2, a shoulder singularity occurs.

The following figure is a schematic diagram of the shoulder singularity. The blue plane refers to the plane that passes through the axis of Joint 1 and is parallel to the axis of Joint 2.

Example point 1: [90,43.4,-105.7,0,-30,0], as shown in the figure below:

Example point 2: [90,43.4,-105.7,0,62.3,0], as shown in the figure below:

Singular Type 2: Elbow singularity

When the intersection point of the axes of Joint 5 and Joint 6 lies on the plane formed by the axes of Joint 2 and Joint 3, and q3=0, i.e., the point format is [x,x,0,x,x,x], an elbow singularity occurs.

Example point 1: [-90,60,0,0,90,0], as shown in the figure below:

Example point 2: [0,0,0,90,-60,0], as shown in the figure below:

Singular Type 3: Wrist singularity

When the axes of Joint 4 and Joint 6 are parallel, q5=0, i.e., the point format is [x,x,x,x,0,x], a wrist singularity occurs.

Example point 1: [0,60,30,0,0,0], as shown in the figure below:

Singular Type 4: Boundary singularity

When the robot end-effector reaches the farthest point, q3=0 and q5=0, i.e., the point format is [x,x,0,x,0,x], a boundary singularity occurs.

Example point 1: [0,0,0,0,0,0], as shown in the figure below:

Example point 2: [-90,90,0,0,0,0], as shown in the figure below:

Example point 3: [-90,45,0,0,0,0], as shown in the figure below:

Load curves

Represent the curves of end load of RM65-B and RM65-6F and RM65-6FB, respectively. Where, L refers to the radial distance of the center of mass of end load against the plane of end flange, and Z refers to the normal distance of the center of mass of end load against the plane of end flange.