LUS2 hands-on for beginners: from power-on to a working pick-and-place loop

A friend recommended the LUS2 from Luming to me. His exact words were "springs up in one second, the world's first full-size." My first reaction was: if you put this thing next to a production line, can it keep up with the takt time, and how long does changeover take. Springing up fast is of course useful, but that's something that happens after it falls over itself—it's a fallback capability, not throughput.

But since someone delivered the machine to my door, I went through it following the old rules for installing a production line, from unboxing to running through the simplest pick-and-place cycle. This post is for peers who, like me, are touching a full-size humanoid robot for the first time.

First, let me clarify a few terms. Teaching means manually guiding the robot through a motion, it records each position, and then repeats it on its own. Joint torque is how much force a joint has—in the LUS2 materials both 360 and 400 Nm appear; the one I saw, calculated from the nameplate, is—refer to factory specs for the exact figure. Payload is the maximum weight it can hold in its hands; this one is rated at 3 kg. Weight too—both 55 kg and 57 kg are mentioned; the difference is small and doesn't affect judgment.

Placement and power-up are nothing special—just find a flat, hard surface. Don't try it on tile or a slope; a humanoid robot stands on two legs, and if the ground is uneven it constantly makes micro-adjustments, driving up power consumption and heat. Leave more than 1.5 meters around it, and don't leave cables lying on the floor. First confirm the emergency stop button is released—twist it clockwise—then close the main power, then press the power button on the body. Wait for self-check; the joint indicator lights go from blinking to steady, and the host computer interface shows each joint's angle and battery level. This step takes about one or two minutes. The interface version may differ from what I got, but the logic is similar—first check for red alarms, clear them if any, and don't rush ahead.

Next, connect. On the same LAN, enter the address on the body into the host computer; once connected you can see real-time posture. Then have it go from a crouch to a standing ready pose—you'll hear a series of slight joint movements, which is normal.

To teach a pick-and-place cycle, first switch to drag mode—this step is the most critical. If you don't switch modes and just push it by hand, at best you get an alarm, at worst you damage the reducer. Hold the forearm, slowly guide it to the pick point, click record point on the interface, name it pick. Lift and move to a transition point, record as via—this point is to avoid the edge of the material bin, don't skip it. Go to the place point, record as place. Set the gripper open/close, confirm the object being grabbed is within 3 kg. Execute step by step once, with a person standing next to the emergency stop. On my side, from switching modes to running through the single step took less than half an hour, half of which was spent tuning the transition point.

If the single step is fine, run continuously. On my side, one pick-and-place cycle is about a dozen seconds, depending on the distance between the two points and how smooth the transition point is. I ran continuously for twenty minutes; joint temperatures were in the normal range, and takt time didn't drift noticeably. A forklift passed by once in the middle, and the machine reported a posture deviation; after resetting it continued running.

There's another method: directly input coordinates instead of dragging—enter point coordinates in the interface. The advantage is consistency; the disadvantage is you have to measure every point with a ruler, and changeover means redoing everything. What I ended up using was teaching by dragging, then saving the points as a recipe, and adjusting the recipe for changeover. Saves hassle, but once there are many points it gets messy—that's a story for another day.

Let me mention a few pitfalls I hit. Pressing start and nothing happens—80% of the time it's because the emergency stop wasn't reset or the last alarm wasn't cleared. Forgetting to switch modes before dragging and pushing hard—this is the most common. After power-off and power-on you need to home; I replied in another thread a few days ago that you shouldn't rush to mount the joint module on the machine the first time you power it up—that was also about zero direction. Same here: skipping homing and running the program directly, I nearly crashed into the material bin. Overloading won't error out immediately—it first shakes, and only when it shakes do you notice.

Next step I plan to move it to an actual workstation, handshake signals with the conveyor line, and move only when material is in place. But there's one number I haven't figured out yet: how long it actually takes to re-teach points during changeover. On-site dragging changes are fast, but once there are many points it gets messy—whether recipe management can hold up, only running it a few times will tell.