From db2c02c680e8f09af59c71fa515e17e3e486db07 Mon Sep 17 00:00:00 2001 From: Paul Guenette Date: Mon, 25 Mar 2019 20:04:45 +0100 Subject: [PATCH 1/2] Allow for regen current before braking --- Firmware/MotorControl/low_level.cpp | 8 ++++---- Firmware/MotorControl/odrive_main.h | 1 + 2 files changed, 5 insertions(+), 4 deletions(-) diff --git a/Firmware/MotorControl/low_level.cpp b/Firmware/MotorControl/low_level.cpp index 6125c99c..d2b995db 100644 --- a/Firmware/MotorControl/low_level.cpp +++ b/Firmware/MotorControl/low_level.cpp @@ -590,10 +590,10 @@ void update_brake_current() { Ibus_sum += axes[i]->motor_.current_control_.Ibus; } } - float brake_current = -Ibus_sum; - // Clip negative values to 0.0f - if (brake_current < 0.0f) brake_current = 0.0f; - float brake_duty = brake_current * board_config.brake_resistance / vbus_voltage; + + // Don't start braking until -Ibus > regen_current_allowed + float brake_current = std::max(-Ibus_sum - board_config.max_regen_current, 0.0f); + float brake_duty = std::max(brake_current * std::abs(board_config.brake_resistance) / vbus_voltage, 0.0f); // Duty limit at 90% to allow bootstrap caps to charge // If brake_duty is NaN, this expression will also evaluate to false diff --git a/Firmware/MotorControl/odrive_main.h b/Firmware/MotorControl/odrive_main.h index 677fb996..dc711015 100644 --- a/Firmware/MotorControl/odrive_main.h +++ b/Firmware/MotorControl/odrive_main.h @@ -71,6 +71,7 @@ struct BoardConfig_t { bool enable_uart = true; bool enable_i2c_instead_of_can = false; bool enable_ascii_protocol_on_usb = true; + float max_regen_current = 0.0f; #if HW_VERSION_MAJOR == 3 && HW_VERSION_MINOR >= 5 && HW_VERSION_VOLTAGE >= 48 float brake_resistance = 2.0f; // [ohm] #else From 8cc30a687da43e327c1a726cfe6a68ed1242e818 Mon Sep 17 00:00:00 2001 From: Paul Guenette Date: Mon, 25 Mar 2019 20:58:30 +0100 Subject: [PATCH 2/2] Add max_regen_current to protocol --- Firmware/communication/communication.cpp | 1 + 1 file changed, 1 insertion(+) diff --git a/Firmware/communication/communication.cpp b/Firmware/communication/communication.cpp index 79982e64..30b511a5 100644 --- a/Firmware/communication/communication.cpp +++ b/Firmware/communication/communication.cpp @@ -152,6 +152,7 @@ static inline auto make_obj_tree() { ), make_protocol_object("config", make_protocol_property("brake_resistance", &board_config.brake_resistance), + make_protocol_property("max_regen_current", &board_config.max_regen_current), // TODO: changing this currently requires a reboot - fix this make_protocol_property("enable_uart", &board_config.enable_uart), make_protocol_property("enable_i2c_instead_of_can" , &board_config.enable_i2c_instead_of_can), // requires a reboot