[Last generated: Wed 4 Oct 2023 15:34:21 EDT]

• 1. Barrett WAM Specs:
  • 1.1 7DOF WAM:
    • 1.1.1 Motors (*1):
    • 1.1.2 Power (*1):
    • 1.1.3 Drive Inertias (*6)
  • 1.2 Barrett Torque Sensor (*2):
  • 1.3 Barrett Hand (*3):
• 2. Power Table
  • 2.1 Battery Status
    • 2.1.1 LiFePo (40152S 15Ah) [Original Robotnik]
    • 2.1.2 LiPo (18650) [Candidate]
    • 2.1.3 Original Charger for Lithium Battery
    • 2.1.4 Comparison Table (online)
    • 2.1.5 Comparison Table (Actual Collection)
      • 2.1.5.a) Discharge vs Charging with Summit:
      • 2.1.5.b) Discharge with Summit and WAM:
  • 2.2 WAM Voltage
    • 2.2.1 WAM Voltage Safty Module
  • 2.3 Other Components Voltage Ranges:
  • 2.4 Power Consumption Table
  • 2.5 DC-DC 48V Regulator For WAM
• 3. Sensors
  • 3.1 L515 Sensor

Frequency: 500 Hz (2 ms) Nescessary in-case one attempts to perform PID gain tuning.

*1. ref: motor power

*2. ref: TS sensor

*3. ref: BHand Spec

*4. Spec: WAM_UsersGuide_AE-00.pdf

*5. Review Paper Ref: 328784157_Light_Weight_Robot_Arms-An_overview#pf3

*6. WAM Inertial Spec

*7. WAM Puck communication

• Ref of Discharging Chart

• datasheet https://www.lifepo4-battery.com/Products/Cylindrical-battery-cell/Headway-40152S-15Ah.html

  • Lifecycle: 2000Cycles.

• Cell	Max Current	Const Voltage	Capacity	Temperature	Nominal Voltage	Discharge (fast cont/max pulse)	Cutoff	BMS Cutoff
  1	2C（30A)	3.6~3.7 V	15 Ah	-20~60 C	3.2 V	45A /150A	2.0 V	-
  16 series	2C（30A)	57.6 V	15 Ah	-20~60 C	51.2 V	45A /150A	32 V	?? 48V?

• Ref of Discharging Chart

• Ref of Charging Stage Chart 18650 DigiKey

  • The 18650 is popular cylindrical lithium cell, with a capacity of 2500 mAh. The datasheet recommends a 1250 mA constant current charge, then 4.2 V constant voltage charge, and charge termination when the current drops to 50 mA. The datasheet specifies a fast charge, which is 4000 mA constant current, then 4.2 V constant voltage, then cut off at 100 mA, which is a C/25 charge termination.

• Cell	Const Current	Const Voltage	Capacity	Temperature	Nominal Voltage	Discharge Continuous (std/fast/max)	Cutoff	BMS Cutoff
  1	1~1.25 A	4.2 V	2.5 Ah	050 C Charging -2075 C Discharge	3.6 V	0.5A / 10A / 20A	2.5V	-
  8 parallel	8A	-	20Ah	-	3.6 V	4A / 80A / 160 A	-	-
  14 series	-	58.8 V	-	-	50.4 V	-	35 V	-
  52 V	8A	58.8 V	20Ah	050 C Charging -2075 C Discharge	50.4 V	4A / 80A / 160 A	35 V	42 V

• 📓 From the chart, the V_float = 54.4V would work during stage 3

  📓 From the table, the V_const_max = 58.8V > 57.6V Const Voltage Charging

  📓 From the table, the I_const_max = 8A > 6.25A Boost Const Current

• Model: PB-360P-48

• Boost Charging V	Float Charging V	Capacity	Output Current	Over Volt Protection	Efficiency
  57.6 V	54.4 V	20~65 Ah	6.25 A	59~64 V	87%

	Discharging Table	Charging Stages
48V	Ref of Discharging Chart	Model: PB-360P-48
52V	Ref of Discharging Chart	Ref of Charging Stage Chart 18650 DigiKey

	Discharge with Summit ON Only	Charge with Summit ON Only
48V
52V

	Discharge with Demo Programs	Discharge with Summit ON and WAM_node Op.
48V	- [5] Joystick interfere to avoid collision. - [2] [5] : demo 14 , moving fwd, wam pointing fwd - [0] [3] : demo 12 , spinning, wam swinging up and down - [1] : demo 13, going circles, wam swinging up and down
52V

• The standard WAM system requires an input voltage of 18-90VDC
• 7-DOF ---> Q(no torque): 27W Typ(2kg payload): 45W Peak: 800W
• Provided WAM Standalone Power Supply switches automatically to local voltage standards (100-120 & 200-240 VAC at 50-60Hz)
  • Output: 10A of direct current at 48V.
• The safety module is configured with respect to 48V

• From safety manual [WAM_UserManual_AH-00.pdf] at pg. 29/80 (4.5.2 Safety Board):

a. SET SAFE 4 (this is necessary; do not skip this step)
b. SET SAFE 5
c. FIND VBUS
d. SET SAFE 0
e. SET VOLTL1 36
f. SET VOLTL2 30
g. SET VOLTH1 54
h. SET VOLTH2 57
i. SET GRPA 1
j. SET GRPB 2
k. SET GRPC 3
l. SAVE
m. RESET
o. GET VOLTL2 (should be 30, else SET and SAVE it again)
p. GET VOLTH1 (should be 54, else SET and SAVE it again)
q. GET VOLTH2 (should be 57, else SET and SAVE it again)
r. GET GRPA (should be 1, else SET and SAVE it again)
s. GET GRPB (should be 2, else SET and SAVE it again)
t. GET GRPC (should be 3, else SET and SAVE it again)

• We need a DC-DC Regulator for WAM at 48V and 10A or more

  • (Current Fuse Max at 10A)
  • Rated load at 120 W with 2kg load and BHand
  • Max Peak at 800 W
  • Old: 50V * 10A = 500 W, and never had blown the fuse
  • WAM Software Protection @48V: 54V Warning, 57V Cut-off

  Item	Type	Price	DCV_i	V_o	I_o_rate	Regulator Topology	Notes	Efficiency
  Digikey - ISL81801EVAL2Z	Dev Board	$189.86	32~80	48V	5A	Buck-Boost @ 200kHz	UV/OV/OC/OT protection	>95% when >1A <60V
  Mouser - VFK400W-DIN	Rail Mount Enclosed	$904.23	18~75	48V	8.3A	250kHz	UV/OV/OC/OT protection, isolated, heat sink	87%
  Not-stock Mouser - VFK600-D48-S48-DIN	Rail Mount Enclosed	$838.02	36~75	48V	12.5A		UV/OV(x1.15-1.4)/OC/OT protection, isolated, heat sink	92%
  19 in stock Digikey - VFK600-D48-S48	7.84" L x 4.99" W x 1.54" H (199.1mm x 126.8mm x 39.1mm)	$714.65	-	-	-	-	-	-
  153 in stock Digikey - SD-500L-48	8.46" L x 4.53" W x 1.97" H (215.0mm x 115.0mm x 50.0mm)	239.57 $229.45 (Mouser)	19~72	adjustable 46~60V	10.5A	Isolated DC-DC	forced air cooling, OV 62~68V, Remote-ON/OFF with 4-10V wire signal	89%
  DDR-480C-48 Mouser - 29 in stock vs Digikey	Isoltated DIN Rail 129mm x 85.5 mm x 125.2 mm	306.86 $291.90 (Digikey)	33.6 ~ 67.2 V	adjustable 48~56V	10A	Isolated DC-DC	All Protections, Isoltated, Remote ON-OFF, Current Sharing	92%
  **3 in stock RSD-500C-48 Digikey Mouser**	9.33" L x 3.94" W x 1.61" H (237.0mm x 100.0mm x 41.0mm)	364.57 $340.56 (Mouser)	33.6~67.2	48V	9.6A		Isolated	93%
  13 In Stock Digikey - DC2456A Dev Board	Dev. Board	$363.74 $348.39 (Mouser)	16V ~ 120V	48V	10A	Buck-Boost @ 200kHz	Dev. Board	98.7%

• Allan Variance Based on 3 Hour Idling Camera IMU

$ rosrun allan_variance_ros analysis.py --data data/allan_variance.csv
ACCELEROMETER:
X Velocity Random Walk:  0.00137 m/s/sqrt(s)  0.08200 m/s/sqrt(hr)
Y Velocity Random Walk:  0.00179 m/s/sqrt(s)  0.10751 m/s/sqrt(hr)
Z Velocity Random Walk:  0.00200 m/s/sqrt(s)  0.11988 m/s/sqrt(hr)
X Bias Instability:  0.00030 m/s^2  3869.16005 m/hr^2
Y Bias Instability:  0.00055 m/s^2  7163.72035 m/hr^2
Z Bias Instability:  0.00030 m/s^2  3869.13542 m/hr^2
X Accel Random Walk:  0.00004 m/s^2/sqrt(s)
Y Accel Random Walk:  0.00015 m/s^2/sqrt(s)
Z Accel Random Walk:  0.00009 m/s^2/sqrt(s)
GYROSCOPE:
X Angle Random Walk:  0.00863 deg/sqrt(s)  0.51793 deg/sqrt(hr)
Y Angle Random Walk:  0.00611 deg/sqrt(s)  0.36681 deg/sqrt(hr)
Z Angle Random Walk:  0.00460 deg/sqrt(s)  0.27610 deg/sqrt(hr)
X Bias Instability:  0.00161 deg/s  5.79476 deg/hr
Y Bias Instability:  0.00111 deg/s  3.99853 deg/hr
Z Bias Instability:  0.00037 deg/s  1.33671 deg/hr
X Rate Random Walk:  0.00041 deg/s/sqrt(s)
Y Rate Random Walk:  0.00027 deg/s/sqrt(s)
Z Rate Random Walk:  0.00007 deg/s/sqrt(s)
Writing Kalibr imu.yaml file.
Make sure to update rostopic and rate.

> Back To Top <