{"id":424,"date":"2014-08-26T15:13:54","date_gmt":"2014-08-26T19:13:54","guid":{"rendered":"http:\/\/coro.etsmtl.ca\/blog\/?p=424"},"modified":"2014-09-14T11:01:10","modified_gmt":"2014-09-14T15:01:10","slug":"precise-automations-pf400-collaborative-scara-robot","status":"publish","type":"post","link":"https:\/\/coroblog.etsmtl.ca\/?p=424","title":{"rendered":"Precise Automation’s PF400 collaborative SCARA robot"},"content":{"rendered":"

\"PreciseSix months ago, after the publication\u00a0of our revelatory\u00a0feature article<\/a> regarding the safety of Universal Robots’ UR5 collaborative robot arm, Precise Automation\u00a0expressed their interest\u00a0to have\u00a0their one-of-a-kind\u00a0PF400 collaborative SCARA robot<\/em>\u00a0undergo a similar study in our lab. The company\u00a0claims that the PF400 is “intrinsically safe since all of the forces generated by its axes are limited so that the robot cannot hurt a user even if it collides with them at full speed.”\u00a0I asked one of our undergraduate students to test the\u00a0demo unit that we received on loan.\u00a0So does he think\u00a0we should leave\u00a0the PF400 fenceless?<\/p>\n


\nPrecise Automation<\/a> is a small company based in California, It was founded in 2004 by\u00a0Mr. Brian Carlisle and Dr. Bruce Shimano, who were the founders of Adept Technology<\/a>\u00a0and\u00a0key members of the team that developed the PUMA robot for Unimation. Precise Automation develops motion controllers, vision systems, Cartesian robots and SCARA robots. Their PreciseFlex SCARA robot was introduced several years ago as a “4-axis sample handler, with servo gripper, that is ideal for benchtop applications where price, ease-of-use, space requirements and safety are critical.”<\/p>\n

The PF400<\/a>\u00a0was released last year, but the PreciseFelx SCARA has been collaborative since it was released four years ago for the Life Science market.<\/span>\u00a0It\u00a0uses servo motors equipped with absolute encoders and moves very quietly. Its controller is embedded inside the robot arm, which results in a very small footprint. The PF400 does not come with a physical teach pendant. The robot\u00a0can be controlled using a web interface or it can run stand-alone\u00a0in automatic mode. Teaching robot positions\u00a0by demonstration\u00a0is easy. Motors on axes 2, 3 and 4 can be deactivated (they don’t have brakes), while the break\u00a0on axis 1 can be released by pushing a button beneath the proximal link\u00a0of the robot. The robot\u00a0can be programmed by using so-called motion blocks or with the help of a custom\u00a0programming language.<\/p>\n

PF400’s\u00a0payload is only 0.5 kg and its linear speed is limited to 500 mm\/s. In manual mode, the linear speed is further limited\u00a0to 250 mm\/s. Nevertheless, we performed a series of impact tests using our AMTI six-axis force plate. The maximum impact force registered during vertical motion (axis 1 only) was about 420 N. The maximum force in a horizontal motion was only 360\u00a0N. Furthermore, at large impacts, the robot is deactivated almost immediately (after 0.02 s) and the residual forces are very small (about 50 N in the case of vertical impact). Note, however, that our tests do not necessarily represent reality. Although we placed a small rubber mat\u00a0on the robot at the impact location, this mat does not have exactly the same compliance as the different parts of the human body. A larger compliance will obviously lead to smaller impact forces and vice versa.<\/p>\n

 <\/p>\n